Anatomy & Physiology 2 final

Cholesterol derivatives, hydrophobic, require protein carriers, bind intracellular nuclear receptors, affect gene transcription, lipid soluble, stored in fat.

Amino acid-based, hydrophilic, bind extracellular receptors, use cAMP second messenger system.

• Thyroid hormone is an exception: hydrophobic due to tyrosine.

Hormone binds ec membrane receptor. G-protein activates. Adenylate cyclase enzyme activates + catylazes ATP to become cAMP(second messenger). cAMP activates protein kinase A. Proteins are phosphorylated. Cell response occurs.

single amino acids (amine hormones) to several amino acids (peptide hormones) to complete proteins (protein hormones)

Stimulates another endocrine gland to secrete hormones;

• controls hormone secretion from other organs.

• Not trophic hormones, which induce target cell growth.

Small bean-sized organ in sella turcica of sphenoid bone;

• anterior lobe -(adenohypophysis, glandular),

• posterior lobe (neurohypophysis, nervous).

Anterior pituitary (adenohypophysis) + posterior pituitary (neurohypophysis).

Large blood vessels formed by merging capillaries; travel through infundibulum;

specialized blood supply between hypothalamus and pituitary gland.

Hypothalamic neurons in paraventricular and supraoptic nuclei produce hormones that travel down infundibulum and stay stored in axon terminals until Action potential fired allowing release into posterior pituitary capillaries.

pathway that tranpsorts adh +oxytocin from hypothalamus to pos pi.

ADH antidiuretic hormone/vasopresin

Source: Hypothalamus produced Posterior released /stored

Target: Kidney

Effects: Increase kidneys water retention (water reabsorption)

(decrease urine production)

Insertion of aquaporins in tubules cells

Decreases blood solute concentration

Increases blood volume

Source: Hypothalamus produced Posterior pituitary released/stored

Target: mammary glands + uterus

Effect: Milk let down reflex

infant suckling triggers contraction of glands resulting in milk ejection

positive feedback

Uterus contractions triggered by stretch

Follicle stimulating hormone

Source: Ant. Pituitary

Target: Gonads

Effects:

secrete chemical to bind + concentrate testosteron

triggers estrogen production + maturation of ovarian follicles

Thyroid stimulating hormone

Source: Anterior pit.thyrotrophs

Target: Thyroid

Effect: Development/growth of thyroid gland + hormone secretion t3, t4, stimulated by TRH

adrenocorticotropic hormone

Source: ant. pit

target: adrenal cortex

Effects: growth of adrenal cortex + production of steroid hormones

Luteinizing hormone (gonadotropin)

Source: Ant.pit

Target: gonads

Effect:

stimulates testosteron production in testes

release of oocyte 4 ovulation and production of estrogen + progesterone

Prolactin - Non tropic

Source: ant. pit

target: mammary glands

Effect: growth of mammary glands, initiation of milk production + maintenance

Growth hormone - Non tropic

Source: Ant. pit

Target: liver, muscle, fat, cartilage

Effect:

Short - lipolysis(fat breakdown) + gluceonegenesis (new glucose)

decreases muscle uptake of glucose (^ blood glucose)

So cell can use glucose + FA for cell growth.

Long: IGF stimulation

Insulin like growth factor

Source: liver

target: nearly all cell

Effect: prolong + mediat GH effects - LONG TERM

increases protein synthesis + cell division. + growth

Increases cell uptake of glucose (opposing GH effect)

Thyroid hormones

Source: Thyroid follicular cells

Target: all body cell

Effect:

regulation of the metabolic rate and thermoregulation,

promotion of growth and development

synergism with the sympathetic nervous system.

Source: parafollicular cells of thyroid gland

Target: bone osteoclast

effect: decrease in blood calcium from inhibition, short term

Parathyroid hormone

Source: chief cells of parathyroid glands

Target: bone, kidneys are small intestines

Effect: increased blood calcium

• bone breakdown, increase calcium reabsorption from tubule

• indirectly enhances dietary calcium in small intestine by stimulating kidney to convert vit D

mineralocorticoid

Source: adrenal cortex, zona glomerulosa

Target: kidney tubules

Effect: sodium reabsorption + water follows from distal tubule. and H+ and K+ secretion

Increases blood pressure/volume

Source: adrenal cortex glucocorticoid

Target: liver, muscle, adipose tissue, white blood cells

Effect:

Increases gluconeogenesis in liver

Increases protein breakdown in muscle

Increases lipolysis in adipose tissue

^ blood glucose

Inhibits inflammatory response/Helps body respond to stress

Main: insulin and glucagon;

others: thyroid hormone, growth hormone, cortisol.

Islet of Langerhans;

• alpha cells secrete glucagon (raises blood glucose),

• beta cells secrete insulin (lowers blood glucose).

Source: Produced by alpha cells of pancreatic islets;

Target: liver, muscle, fat

Effect: increases blood glucose by stimulating glycogenolysis(breakdown), gluconeogenesis(new), protein and fat breakdown, and ketone body formationfuel source from FA in liver).

Pituitary gland

Thyrotropin Releasing Hormone

Source: Hypothalamus

Target: Ant. pit

Effect: stimulates release of TSH

Gonadotropins Releasign Hormone

Source: Hypothalamus

Target: Ant. pit

Effect: stimulates release of gonadotropins FSH,

Source: Hypothalamus

Target: Ant. pit

Effect: stimulates release of GH

Thyroid hormones T3 and T4 increase the basal metabolic rate of most body cells. This increases ATP use and heat production, supports normal growth and nervous system development, and increases sensitivity to the sympathetic nervous system.

increased blood calcium

Bone: Stimulates osteoclast releasing calcium ion into blood

Kidney: increases calcium reabsorption from kidney tubules

Small intestine: indirectly enhances dietary calcium/intestine absorption through kidney activation

• kidney converts vitamin D to active form (Calcitriol)

Adrenal medulla: neuroendocrine organ

epinephrine & norepinephrine (effects are similar to the sympathetic nervous system – fight or flight)

when (hypothalamic ) capillaries drained by (portal) veins then transports to second group of capillaries (in anterior pitituary).

Source: beta cells of pancreatic islets

Target: liver, skeletal muscle, cardiac muscle, adipose tissue, some brain areas

Effects:

• Decreases blood glucose

• Increases glucose, amino, lipid uptake by cells

• Increases glycogen + fat synthesis

• satiety

Destruction of beta cells by immune system, causing low insulin and hyperglycemia. Cells starve because no way to go from blood to cells w/o insulin.

signs

Glucos/ketonuria glucose/ketone in urine

Polyuria: frequent urination

Polydipsia: thirst

Hunger

treatment: insulin injection + monitiring diet

Insulin resistance, impaired beta-cell response, body cells do not respond properly to insulin

Cause: heredity + obesity

Similair signs.

treatment: lifestyle changes, insulin

Irregularly shaped organ found in the mediastinum, larger in infants, replaced with adipose in adults

-  Hormones (thymosins) lead to development of T cells  – important for immune system 

• Site of T-lymphocytes(white blood cell) maturation involved in immune response 

• Thymus secretes hormones thymosin and thymopoietin that target T-lymphocytes for maturation 

ovaries + testes.

• the gonads produce the sex steroid hormones that are responsible for gamete production and have multiple other function

• Estradiol 

• Progesterone 

• Inhibin 

• Testosterone  - steroid

• Inhibin 

epithalamus, posterior diencephalon

Secrete melatonin when ambient light decreases in the evening, and it reaches its peak secretion over the nighttime hours.

Source:pineal gland

Target:brain stem/reticular formation (sleep regulating center)

effect: regulates sleep wake cycle in response to light. 

Source: ovaries (corpus luteum)

target: uterus/reproductive tissues

effect: prepares body pregnancy/fetus

• peaks after ovulation

• mammary gland development

• smooth muscle, temp regulation, blood clotting, bone tissue, + metabolism  

Source: ovaries, type of estrogen

Target: reproductive organs, bone, blood

Effect

• Development of secondary sex characteristics

• regulation of menstrual cycle

• reduced bone breakdown

• increases HDL and decreases LDL cholesterol

• blood clot risk 

Source: ovaries/testes 

Target: anterior pituitary

 Primary effect: inhibits FSH secretion through negative feedback 

Source: testes

Target: reproductive organs, bone, skeletal muscle, and other tissues

Effect: Development of secondary sex characteristics

• increase bone + muscle

• Supports sperm production

• Stimulates development of male reproductive organs

Active vitamin D

Source; kidney, stimulated by PTH from para glands

Target: small intestine

Effect: increases intestinal absorption of calcium ions, by conversion to active form

Erythropoietin

Source: kidney

target: red bone marrow

Effect: stimulates erythrocytes/RBC production, to increase oxygen in blood

produces a vitamin D precursor in response to UV light.

involved in the vitamin D precursor pathway before vitamin D is activated by the kidneys into calcitriol.

Atrial natriuretic peptide

Source: cardiac muscle cells of heart

Target: Blood vessel smooth mucle + kidney tubules:

Effect: Causes vasodilation

• Increases sodium excretion: natriuresis

• Water follows sodium into urine

• Decreases blood volume

• Decreases blood pressure

Slightly left in the thoracic cavity’s mediastinum, within the pericardial cavity.

• The right side of the heart pumps deoxygenated blood to the lungs through the pulmonary trunk/arteries.

• The left side of the heart receives oxygenated blood and pumps it to the body through the systemic circuit.

Gas exchange occurs between alveoli and pulmonary capillaries: O₂ diffuses from alveoli into blood, and CO₂ diffuses from blood into alveoli to be expired.

Pulmonary veins.

O₂ diffuses from blood into tissues, and CO₂ diffuses from tissues into blood, making the blood deoxygenated and returns by systemic veins to SVC/IVC.

Pulmonary circuit = low pressure, short distance to lungs. Systemic circuit = high pressure, greater distance to body.

Part of the thoracic cavity that contains the heart, pericardium, and pericardial cavity.

A membranous sac surrounding the heart that helps reduce friction and protect/anchor the heart.

• consists of fibrous + serous pericardium

• Tough outer layer of the pericardium that anchors the heart and prevents overfilling.

• Thin membrane of the pericardium made of

• parietal + visceral layers.

Layer of serous pericardium fused to the inside of the fibrous pericardium.

Layer of serous pericardium that covers the heart surface; also called the epicardium.

Space between the parietal and visceral pericardium that contains pericardial fluid.

• fluid acts as a lubricant and prevents friction as the heart beats.

peri/Epicardium, myocardium, endocardium.

Outermost layer of the heart wall; same as the visceral pericardium.

Middle and thickest heart wall layer; composed of cardiac muscle and fibrous skeleton.

Which heart wall layer does the pumping? Myocardium.

Deepest layer that lines the heart lumen/chambers; composed of simple squamous endothelium and continuous with blood vessel lining.

Which heart wall layer lines the chambers?Endocardium.

• Superior vena cava, inferior vena cava, and coronary sinus.

• Pulmonary veins.

• Receive blood from veins.

• Pump blood into arteries.

• Pumps blood into the pulmonary trunk/pulmonary circuit.

• Pumps blood into the aorta/systemic circuit.

Right ventricle is thinner; cresent

left ventricle is thicker because it pumps against higher systemic pressure.

External groove separating atria from ventricles; holds right and left coronary arteries.

External groove marking the separation between the right and left ventricles.

Thin internal wall separating the right and left atria.

• fossa ovalis indent in the interatrial septum; remnant of fetal foramen ovale.

Thick muscular wall separating the ventricles; contracts to help expel blood. AV bundle location

Muscular ridges on the internal anterior surface of the right atrium.

Ridges - Irregular protrustions of cardiac muscle on the internal ventricular surface.

Cord-like structures that attach papillary muscles to AV valve cusps.

Prevent AV valves from flipping backward into the atria during ventricular contraction.

• Keep blood flowing in one direction and prevent backflow.

• In response to pressure changes.

AV - Valves between atria and ventricles that prevent backflow into atria during ventricular contraction.

• Right AV valve Tricuspid valve; between right atrium and right ventricle. 3 cusps

• Left AV valve Bicuspid/mitral valve; between left atrium and left ventricle. 2 cusps

Valves between ventricles and arteries that prevent blood from flowing back into ventricles. 3 cusps

• Pulmonary valve SL valve bt right ventricle and pulmonary trunk;

• Aortic valve SL valve bt left ventricle and aorta;

Do semilunar valves have chordae tendineae/papillary muscles? No.

Valve closure and vibrations in the heart/blood vessel walls.

“Lub”; caused by closing of AV valves.

-Start of ventricular systole/isovolumetric contraction.

-longer and louder

“Dub”; caused by closing of semilunar valves.

Start of ventricular diastole/isovolumetric relaxation.

Systemic capillaries→ systemic veins → SVC → RA → tricuspid valve →RV → pulmonary valve → pulmonary trunk → right/left pulmonary arteries → pulmonary capillaries → pulmonary veins → LA → mitral/bicuspid valve → LV → aortic valve → aorta → systemic arteries → systemic capillaries 2 tissues.

• Right and left pulmonary arteries.

• Left atrium.

• Deoxygenated blood.

• Oxygenated blood.

Cardiac muscle cells; short, branched, usually one nucleus, many mitochondria, striations; Due to alternating contractile proteins used for tension generation.

Structures that join adjacent cardiocytes, including pacemaker and contractile cells.

• Allow heart muscle cells to contract as a coordinated unit.

• Desmosomes - Hold cardiac muscle cells together.

• Gap junctions - allow ions to pass between cells for electrical signal communication. AP spread quickly

Ability of pacemaker cells to spontaneously and rhythmically generate action potentials, setting the heart’s rhythm without nervous system input.

Three populations of pacemaker cells responsible for action potentials that pace the heart: SA node, AV node, and Purkinje fiber system.

• SA node → AV node → AV bundle → bundle branches → Purkinje fibers.

Sinoatrial

• Right atrium, inferolateral to the superior vena cava.

• Fastest rate of depolarization; sets sinus rhythm/pace for the heart.

Atrioventricular

• Posteromedial to the tricuspid valve

• Delays the signal so atria contract first and ventricles have time to fill before contraction.

Delay in conduction that allows atria to contract before ventricles.

• Delays the signal so atria contract first and ventricles have time to fill before contraction.

Slowest pacemaker group but conducts signals quickly through the ventricles.

• AV bundle, right/left bundle branches, and Purkinje fibers.

AV bundle : Conducts action potentials between atria and ventricles through the fibrous skeleton.

Bundle branches : Carry the signal down the interventricular septum.

Purkinje fibers : Spread the signal through the ventricles to contact contractile cells.

HCN/Na⁺ leak in → threshold → Ca²⁺ in → K⁺ out → repeat.

• slow initial deloparization to -40mv threshold

• Full depolarization - VG open Ca+ influx

• Repolarization: time gate Ca+, VG K+ channels open, K efflux

• Hyperpolarization/minimum potential : K+ open until minumum -> close, HCN open, repeats

Depolarization:VG Na⁺ channels open, rapid Na⁺ influx

Initial repolarization : Na⁺ channels inactivate + a small amount K⁺ leaves

Plateau phase: Slow Ca²⁺ influx and K⁺ efflux keep membrane 0 mV.

Repolarization : K⁺ leaves, returning membrane potential to about -85 mV.

99% of cardiac muscle cells and are triggered by action potentials from pacemaker cells.

• have a stable resting membrane potential unlike SA node cells

It prolongs the action potential, allows Ca²⁺ entry, strengthens contraction, lengthens the refractory period, and prevents tetanus.

Tool for heart examination that records electrical activity of the heart’s contractile cells AP.

Net changes in electrical activity;

Atrial depolarization + Atrial contraction.

1st wave

contraction of all cells except SA node

• SA node contracetion = flat segment after p wave

Ventricular depolarization/Ventricular contraction.

Q = first downward deflection, R = large upward deflection, S = second downward deflection.

• Large complex hides atrial repolarization

Ventricular repolarization.

• Occurs After the S wave and before ventricular relaxation.

Sequence of events from one heartbeat to the next.

• Atria contract at the end of filling to eject remaining blood into ventricles. due to pressure build up

Because of the AV node delay, which allows atria to contract and ventricles to fill before ventricular contraction.

Pressure gradients, not contraction force directly.

• Ventricular filling

• isovolumetric contraction

• ventricular ejection

• isovolumetric relaxation.

1. Blood flows from atria into ventricles; AV valves open, semilunar valves closed; ends with EDV.

1. Ventricles start contracting; AV valves close causing S1 Lub; all valves closed, so volume stays the same. EDV

3.Ventricular systole continues; semilunar valves open; blood is ejected.

• volume ejected = Stroke volume, SV 70ml

• ESV 50 mL

4.Ventricles relax; semilunar valves close causing S2 dub; AV valves are closed; all valves closed, so volume stays the same.

ESV

Starts again when

• Ventricular pressure drops, AV valves open, and ventricular filling begins.

• End-diastolic volume; blood in ventricles after filling. 120ml

• End-systolic volume; leftover blood in ventricles after contraction/ejection. 50mL

Amount of blood pumped in one heartbeat/cycle.

SV = EDV - ESV.

Preload increases, stretch increases, contraction is stronger, and SV increases.

What happens if ESV increases? Less blood was ejected, so SV decreases.

Amount of blood pumped by each ventricle into the circuits in 1 minute.

CO = SV × HR.

mL/beat × beats/min = mL/min.

Preload, contractility, and afterload.

Blood/stretch imposed on the heart before contraction; stretch of ventricular cells.

EDV

EDV is proportional to SV; more blood in the heart before contraction causes more blood to be ejected.

• More filling → more stretch → stronger contraction → higher stroke volume.

Strength of contraction for a given preload; tension-generating ability.

• increase: More blood is ejected, SV increases, and ESV decreases.

• De: Less blood is ejected, SV decreases, and ESV increases.

Resistance to blood being ejected from the ventricles; force the ventricles must overcome.

increase:SV decreases and ESV increases.

Decrease: SV increases and ESV decreases.

- EDV - pre

- ESV

-ESV

Number of heartbeats/cardiac cycles per minute.

The rate at which the SA node generates action potentials.

• Pulse: Pressure wave/recoil felt in arteries as blood is ejected from the heart.

• pulse reflect HR

Carry blood away from the heart.

They are the distribution system of the vasculature.

branch into smaller

Very numerous, tiny vessels where exchange happens in beds.

They are the exchange system.

Veins

-They are the collection system and also act as blood reservoirs because they hold a lot of blood at low pressure.

merge into larger

Innermost layer.

Contains endothelium, which is simple squamous epithelium lining the lumen.

Middle layer. Contains smooth muscle, allowing vasomotion.

Vasomotion = changing vessel diameter.

AKA adventivia

Outermost layer.

Connective tissue that supports/protects the vessel. prevents overstretch

• largest w estatic tissue to stretch + recoil w heartbeat

• internal and external elastic lamina on either side of tunica media  helps w recoil

• under high pressure

named for organs/regions

deliver blood to specific organs.

thick tunica media

Small arteries that control blood flow into tissues.

• They are major resistance vessels.

Smallest arteriole that connect arterioles to capillary beds.

• directly feed capillary beds into most tissues

Ring of smooth muscle that controls whether blood enters a capillary bed.

• Open or close to control blood flow into true capillaries.

Least leaky.

Have tight junctions. transcytosis

Found in places like muscle, skin, nervous tissue, and connective tissue.

Have pores/fenestrations.

More leaky than continuous capillaries. allow water = small solutes thru osmosis

ound where rapid exchange is needed, like kidneys, endocrine glands, and small intestine.

Leakiest.

Large gaps/irregular structure.

Allow large substances or cells to pass.

Found in liver, spleen, bone marrow, and lymphoid organs.

• large lumens

• thinner walls than arteries

• valves to prevent backflow

• blood reservoir

Prevent blood from flowing backward, especially in limbs where blood has to move against gravity.

Connection between vessels bt alternative path of blood flow.

Collateral circulation

• Alternate pathway for blood flow if one vessel is blocked.

Connection between arteries to meet tissue demands. common for heart + brain

Connection between veins via small calaterals creating weblike networks that can be seen under skin

Direct connection between an artery and a vein without going through a capillary bed.

This acts like a shunt.

-can regulate temp through blowflow to the skin or redirect blood away from non functioning organs in fetus

Study of blood flow.

fastest in arteries → slowest in capillaries → increases again in veins

but still slower than artery

Blood flow to an area of tissue through capillary bed.

Blood pressure = force blood exerts on vessel walls.

Blood flow is inversely proportional to resistance; that is, as resistance increases, blood flow decreases.

• Pressure during ventricular contraction.

• Pressure during ventricular relaxation.

Difference between systolic and diastolic pressure.

120/80 → pulse pressure = 40 mm Hg.

Mean arterial pressure.Average arterial pressure during one cardiac cycle.

MAP = diastolic pressure + 1/3 pulse pressure

• pulse pressure (systolic - diastolic)

• 95mmHG

highest + pulsatile in arteries

↓dampens in arterioles

↓lower and smoother in capillaries

↓very low and smooth in veins

• Arterioles are where pressure drops a lot because they create major resistance.

1. Cardiac output

-If CO increases, BP usually increases.

2. Blood volume

-If blood volume increases, BP increases.

3. Peripheral resistance

-If resistance increases, BP increases.

blood vessel radius, blood viscosity, and blood vessel length

• Longer vessels = higher resistance.

• Thicker blood = higher resistance.

• Small changes in radius cause big changes in resistance.

Vasomotion

Local vessels can constrict/dilate to direct blood to specific organs or tissues.

Example: active skeletal muscle gets more blood during exercise.

Sympathetic

• norepinephrine and epinephrine

• Increase BP, HR, contractility, cardiac out, PR, vasoconstriction

Parasympathetic

• acetylcholine

• Decrease BP, HR, CO, contractility (mild)

Cardiac output and peripheral resistance are the two factors that determine the pressure gradient driving circulation.

CO*PR=

Venous return = blood returning to the heart.

Because veins have low pressure, they need help.

Skeletal muscles squeeze veins during movement.

Valves prevent backflow, so blood moves toward the heart.

• Pressure changes during breathing help move venous blood back to the heart.

• Increases venous return because skeletal muscle pump is more active.

• Can cause venous pooling because blood is not being pushed back efficiently.

vessel radius   = most important physiologically  

Renin

• Released by kidneys when BP is low.

Angiotensin II

• Powerful vasoconstrictor

• Raises peripheral resistance + BP

• + stimulates aldosterone

Aldosterone

• Increases Na⁺ kidneys reabsorption

• Water follows Na⁺, so blood volume increases

• raises BP

ADH

• Inc kidney water retention

• Raises blood volume + BP

ANP

• Released by the heart when blood volume is high.

• Promotes sodium and water loss.

• Lowers blood volume and BP.

RAAS + ADH = raise BP

ANP = lowers BP

High blood pressure.

20%, associated w heart, kidney disease, etc. 1 modifiable risk factor = silent killer

Low blood pressure.

• hypovolemia - reduced blood volume, from fluid loss,

Diffusion through endothelial cells

Used for lipid-soluble substances to enter/exit cell to blood or fluid

Examples: travel of nutrients, ions, wastes,

• oxygen

• carbon dioxide

Movement of fluid by force out of the capillary due to pressure.

The force that a fluid exerts on the wall of its container. Drives water out

• Blood hydrostatic pressure drives fluid out of capillary 

Movement of fluid back into the capillary.

Pulls fluid into the capillary.

• due to plasma proteins, especially albumin.

The direction of fluid movement depends on the balance between:

• hydrostatic pressure pushing fluid out

• colloid osmotic pressure pulling fluid in

• More fluid moves out.

• More fluid moves in.

Excess fluid in the interstitial space.

Can happen if:

• hydrostatic pressure is too high

• colloid osmotic pressure is too low

• capillaries become too leaky

Ascending aorta - 3 branches

• Brachiocephalic trunk - 2 branches

  • right subclavian artery

  • right common carotid artery

• Left common carotid artery

• Left subclavian artery

Thoracic, abdominal = descending

Common iliac arteries - Terminal branches of abdominal

• internal iliac artery

• external iliac artery

Vertebral artery

• Helps supply brain. branch of right subclavian

External carotid artery - branch from common anteriorly

• Supplies superficial head, face, and neck.

Internal carotid artery - Branch from common superiorly

• Supplies brain and eyes.

• Brachiocephalic trunk - 2 branches

• Left common carotid

• Left subclavian

• Right common carotid

• Right subclavian

Celiac trunk

• Supplies upper abdominal organs like stomach, liver, spleen, pancreas.

Superior mesenteric artery

• Supplies small intestine and much of large intestine.

Renal artery

• Supplies kidneys.

Inferior mesenteric artery

• Supplies remaining large intestine.

Subclavian → axillary → brachial → radial + ulnar

1. Subclavian → Armpit. axillary → media upper arm .brachial → . thumb radial + ulnar. pinky

External iliac → femoral → popliteal → anterior tibial + posterior tibial

bigger. External iliac → straight branch. femoral → kneee. popliteal → anterior tibial + posterior tibial

Merge to form the superior vena cava.

left side = 3rd aorta branch

Drains blood from structures superior/inferior to the diaphragm into the right atrium.

External jugular vein

• Drains superficial face/head/neck.

Internal jugular vein

• Drains brain, deep head, and neck.

Vertebral vein

• Drains posterior neck.

all from right brachiocephalic vein

Superficial/deep pathway includes:

• ulnar vein

• radial vein

• median cubital vein - arm fold

• basilic vein - Basic Boob

• cephalic vein - outer

• brachial vein

• axillary vein

• subclavian vein

Median cubital vein is commonly used for drawing blood.

Great saphenous vein

• Superficial medial lower limb.

Femoral vein

• Major deep vein of thigh. middle unlike artery

Carries nutrient-rich blood from digestive organs/spleen to the liver for processing.

Drain processed blood from the liver into the inferior vena cava.

Higher up and 2

Hepatic portal vein = goes TO liverHepatic veins = leave liver TO IVC

Blood is a fluid connective tissue made of: Plasma, Serum, formed elements, Hemocrit

matrix of blood; contains plasma proteins (albumins, globulins, fibrinogen), nutrients, dissolved gasses and electrolytes 

• Albumins: help maintain colloid osmotic pressure, which keeps water in the blood

• Globulins: include transport proteins and immune proteins/antibodies

• Fibrinogen: clotting protein that gets converted into fibrin during coagulation

• plasma without clotting proteins/fibrinogen, fluid left after clotting happens

plasma = liquid part of blood before clotting

Cells/cell fragments in blood:

• Erythrocytes/RBCs

• Leukocytes/WBCs

• Platelets - cell fragments

Hematocrit = percentage of whole blood that is RBCs.

• Biconcave disc + surface area good 4 gas exchange

• Lack organelles, nucleus, DNA

• Contain hemoglobin

• Contain carbonic anhydrase, which helps with carbon dioxide transport

Their main job is gas transport, especially oxygen.

• Large protein that consists of four polypeptide subunits: two alpha (α) chains and two beta (β) chains.

• 4 globin proteins

• 4 heme groups

• Each heme group contains iron, + the iron binds oxygen.

• Heme = holds oxygen because it has iron.

RBCs last about 4 months, or about 100–120 days.

The spleen is called the RBC graveyard because old/damaged RBCs are trapped and broken down there.

• Globin proteins → amino acids, Iron → recycled

• Heme → converted to bilirubin

• Bilirubin is secreted in bile

• Heme → converted to bilirubin

• Bilirubin is secreted in bile

bile

RBC production in bone marrow,

EPO stimulated from kidney or liver when o2 leves low in blood = hypoxemia

immature RBC precursor.

It still has some leftover organelles/ribosomes but no nucleus. It matures into an erythrocyte.

Adaptation maximizes internal space for hemoglobin (for oxygen transport) and carbonic anhydrase (for CO2 transport/pH balance), allowing for efficient gas exchange and high deformability in capillaries.

Blood type is based on antigens found on RBCs.

Type A, A antigen, anti-B antibodies

Type B, B antigen, anti-A antibodies

Type AB, A+B antigen, No anti-A/B antibodies

Type O, no A or B antigens, Anti-A + anti-B

Positive

• D/Rh antigen is present on RBCs

Negative

• No D/Rh antigen on RBCs

  Antibodies D only form only when an Rh-negative person is exposed to Rh-positive blood + antigen.

• Mother is Rh-negative

• Fetus is Rh-positive

• Mother becomes exposed to fetal Rh+ RBCs

• Mother makes anti-Rh antibodies

• In a later pregnancy, those antibodies can cross the placenta and attack fetal RBCs

antibodies attach to antigens on different RBCs and make them clump.

potentially leading to hemolysis

Recipient antibodies cannot attack donor RBC antigens.

WBCs are involved in immune defense. Use blood to reach tissues (buffy coat).

Large w nucleus

Granulocytes: contain cytoplasmic granules that the cells release when activated

• neutrophils, eosniphil, basophil

AGranulocytes: lack visible cytoplasmic granules.

• lympocytes (B+T)

• monocyte

Never Let Monkeys Eat Bananas

production of WBCs, in bone marrow, all leukocytes arise from hematopoietic stem cells (HSCs). split into two cell lines.

Function:

• Phagocytosis of bacteria

• 3-5

High-yield memory: Neutrophils = bacteria eaters.

Function:

• Increased in allergies

• 2 bilobed, RED

• Also involved with parasitic worm infections

Function:

• Release inflammatory mediators

• S shaped, purple

Bae stop dont flame media

B lymphocytes + T lymphocytes - Agranulocyte

• Involved in immune response

  • B cells make antibodies

  • large nuclues, blue

  • T cells attack infected/cancerous cells and help coordinate immune response

Agranulocyte

• Leave blood and become macrophages

• u- shaped, purple

• Macrophages phagocytize pathogens, dead cells, and debris

cell fragments, important in hemostasis =stopping blood loss.

• Not true full cells, lack nucleus but have mitochondria

• Made from megakaryocyte fragments

• megakaryocyte fragments and help in hemostasis

platelet production.

megakaryoblasts turn into megakaryocyte, undergo uncomplete division.

• large + mature megakaryocytes extend ribbon-like “arms,” or extensions, filled with cytosol, granules, and several organelles.

  force of blood cuts arm into small piece = platelet

• Each arm can give rise to thousands of platelets

Hemopoiesis = production of blood formed elements/cells

• Red bone marrow

Produces:

• RBCs

• WBCs

• Platelets

Hemostasis = stoppage of blood flow/loss from a damaged vessel.

1. Vascular spasm  

1. Platelet plug formation 

1. Coagulation

2. clot retractionn

   1. clot retraction, brings the edges of the wounded vessel closer together + secretes serum

3. thrombolysis

   1. dissolving clot

The damaged vessel constricts.

Purpose:

• Decreases blood vessel diameter

• Reduces blood flow

• Limits blood loss = tissue. repair

Platelets stick/aggregate to the damaged area and to each other.

Purpose:

• Creates a temporary plug over the injury to exposed elastic fibers + release granule content to attract +

Coagulation makes the platelet plug stronger.

Key reaction: Thrombin(platelet) converts fibrinogen into fibrin.

• Fibrinogen = inactive soluble clotting protein

• Fibrin = sticky threadlike protein that glues the clot together

Thrombin(platelet) converts fibrinogen into fibrin.

• Fibrinogen = inactive soluble clotting protein in platelet

• Fibrin = sticky threadlike protein that glues the clot together

Heparin is an anticoagulant.

It prevents or slows clotting.

Thrombus

• A clot that forms and stays in one place in a vessel

Embolus

• A clot or piece of material that breaks loose and travels through the bloodstream

FIL

Fluid recovery

• return excess interstitial fluid back 2 bloodstream so blood volume + Bp dont drop

Immunity

• lymphatic organs+tissues help trap pathogens+house immune cells

Lipid absorption

• lymphatic capillaries in small intestine absorb dietary fats too large to enter blood capillaries directly

interstitial fluid once it enters lymphatic vessels

• Plasma leaks out of blood capillaries → becomes interstitial fluid → enters lymphatic capillaries → now called lymph.

• Can contain: water solutes proteins immune cells pathogens dietary fats from the small intestine

move lymph back toward the blood.

merge to form trunks

• capillaries – closed at one end 

• collecting vessels, lymphatic trunks, two lymphatic ducts (right lymphatic duct + thoracic duct) drain into subclavian veins 

Smallest lymphatic vessels around BV

Key features: away from tissues

• closed at one end, very leaky

• collect extra interstitial fluid, allow immune cells/pathogens to enter

• special lymphatic capillaries in small intestine are called lacteals, which absorb fats

• special lymphatic capillaries in small intestine are called lacteals, which absorb fats

Interstitial fluid → lymphatic capillaries → lymph-collecting vessels → lymphatic trunks → lymphatic ducts → subclavian veins → blood

• The vessels get larger as lymph moves closer to the bloodstream.

merged collecting vessels

Lymphatic trunks drain lymph from body regions.

• lumbar trunks: lower limbs and pelvis

• intestinal trunk: fats from small intestine

• jugular trunks: head and neck

• subclavian trunks: upper limbs

Right lymphatic duct

Drains R upper body

• R side of head/neck, upper limb +thorax

drains into junction of right internal jugular+subclavian veins

Thoracic duct

Drains remaining

• lower body

• L side of head/neck, upper body, thorax, upper limb

• drains into Left internal jugular+subclavian veins junction

immune cells found in lymphatic tissues/organs.

• Natural killer cells

• T lymphocytes / T cells

• B lymphocytes / B cells

• Plasma cells

• Macrophages

Kill abnormal cells, like virus-infected cells and cancer cells, without needing a super-specific antigen match.

• help activate immune responses

• kill infected or abnormal body cells

• They mature in the thymus.

Important for antibody-mediated immunity.

B cells can differentiate into plasma cells.

Plasma cells produce antibodies.

B cell → plasma cell → antibodies

Macrophages are phagocytes.

• engulf pathogens

• clean up dead cells/debris

• help activate other immune cells by presenting antigens

reticular connective tissue filled with immune cells. makes up organ tissue

• fibers form little “nets” that trap pathogens so immune cells can attack them.

MALT = mucosa-associated lymphatic tissue

clusters of b/t cells

It protects mucous membranes, which are areas exposed to pathogens.

• respiratory tract

• digestive tract

• genitourinary tract

specialized lymphoid follicles conisting primary of b cells

• tonsils (pharyngeal, palatine, lingual)

• Peyer’s patches (small intestine ileum)

• appendix (off large intesitne)

Red bone marrow, thymus, lymph nodes, tonsils, spleen 

• site of blood cell production

• B cells mature here

• T cells mature here

• secretes thymosins that help T cell development

• The thymus is most active in children and shrinks with age.

• no follicles so no b cells

• bean shaped organs

• filter lymph

• trap pathogens

• house B cells, T cells, macrophages, and dendritic cells

Lymph nodes swell when immune cells are activated and multiplying.

• cervical nodes: neck axillary nodes: armpit

• inguinal nodes: groin mesenteric nodes: abdomen

Specialized MALT near oral/nasal cavities.

• trap pathogens entering through mouth/nose

Types:

• pharyngeal tonsil/adenoid

• palatine tonsils

• lingual tonsil

Largest lymphoid organ.

• filters blood, not lymph

• removes pathogens from blood

• destroys old RBCs

  • white pulp = immune function, filters pathogens

  • red pulp = destroys old erythrocytes/RBCs

    • red dead

Lymphatic vessels - blinded ended tubes

Lymphatic tissue/organ w clusters of lymphoid follicles(tonsils, lymph nodes, spleen)

all chemical reactions in the body.

Catabolism = breaks molecules down Purpose: releases energy / makes ATP Example: glycolysis, glycogenolysis, lipolysis

Anabolism = builds molecules up Purpose: stores energy / builds body structures Example: glycogenesis, gluconeogenesis, lipogenesis

Breakdown of glucose.Glucose is split into smaller molecules to help make ATP.

Production of glycogen from glucose.

This happens when blood glucose is high and the body wants to store extra glucose.

Breakdown of glycogen into glucose.

This happens when blood glucose is low and the body needs more glucose

Production of new glucose from non-carbohydrate sources.

• Sources can include amino acids, glycerol, lactate, or other compounds.

Production of lipids/fats.

• This happens when the body has extra nutrients/energy and stores them as fat.

Breakdown of lipids/fats.

This happens when the body needs energy from stored fat.

Amino acids are the building blocks of proteins.

• Proteins are broken down into amino acids, and amino acids can be used to build new proteins.

Essential amino acids = the body cannot make them, so they must come from the diet.

Nonessential amino acids = the body can make them.

Complete protein = contains all essential amino acids.

• animal

Incomplete protein = missing one or more essential amino acids.

• Many plant proteins are incomplete by themselves, but they can be combined.

Proteins are not stored

• The body does not store extra amino acids the way it stores glucose as glycogen or fat as triglycerides.

• body will convert them into glucose or fat, or use parts of them for energy.

Cholesterol is a lipid/steroid molecule.

• cell membranes

• steroid hormone production

• vitamin D production

• bile salt production

  Cholesterol is not mainly used for fuel like triglycerides are.

Because lipids are hydrophobic, they do not travel well in watery blood/plasma by themselves.

• So the body packages lipids into lipoprotein complexes.

• HDL and LDL are not cholesterol. They are lipoprotein carriers that transport cholesterol.

Chylomicrons carry dietary lipids from the small intestine into lymph/blood.

VLDL = very low-density lipoprotein

Source: produced by the liver

Function: transports triglycerides from the liver to adipose tissue.

Once triglycerides are removed from VLDL, it becomes LDL.

LDL = low-density lipoprotein

Function: delivers cholesterol to body cells.

Cells need cholesterol for:

• cell membranes + steroid hormone production

LDL = “bad cholesterol” = misleading.

too much LDL means more cholesterol is being delivered to tissues

• can contribute to plaque buildup in arteries.

HDL = high-density lipoprotein

Source: produced by the liver as an “empty shell.”

Function: picks up excess cholesterol from tissues and takes it back to the liver.

• The liver can eliminate cholesterol in bile.

• "good cholesterol" misleading

• lipoprotein that removes excess cholesterol.

• gas exchange of O2 + co2

• helps w speech

• regulate blood ph

• assist w venous blood/lymph flow pressure (pump)

• hormone related - angiotensin II production

conducting zone moves air in and out of the body but does not do gas exchange. It includes structures like the nose, pharynx, larynx, trachea, bronchi, and most bronchioles.

• Air is filtered, warmed, and moistened as it travels in/out

he upper respiratory tract includes the passageways from the nasal cavity to the larynx.

The lower respiratory tract includes the passageways from the trachea to the respiratory tract’s terminal structures, the alveoli.

where gas exchange happens. It includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

provides the body’s cells with oxygen and removes the waste product carbon dioxide.

• pseudostratified ciliated columnar epithelium with goblet cells.

  • Goblet cells secrete mucus, which traps debris and particles.

  • cilia move the mucus toward the pharynx so it can be swallowed or expelled.

1st part of respiratory tract

• warm and humidify the inhaled air;

• filter out debris from inhaled air and secrete antibacterial substances;

• house olfactory receptors; for smell

• enhance the resonance of the voice (

Paired nasal bones

Lateral/alar cartilages

anterior nares - paired nostril openings

nasal septum - divides in to l/r sections

nasal concha (superior, middle, inferior)

nasal meatus (superior, middle, inferior) 

• Meatuses are the air lanes. the lines

• The conchae increase surface area + help create turbulenceo air can be warmed, moistened, and filtered more effectively.

Throat portion after posterior nares

• passageway posterior to the nasal and oral cavities

• nasopharynx, oropharynx, and laryngopharynx.

• Behind the nasal cavity. It extends from the posterior nares to the uvula.

• lined with pseudostratified ciliated columnar epithelium

• so it continues warming, humidifying, and filtering air.

• behind the oral cavity.

• Both air and food pass through it

• lined with nonkeratinized stratified squamous epithelium, which protects against abrasion.

• extends from the hyoid bone to the esophagus.

• Both air and food pass through it

• lined with nonkeratinized stratified squamous epithelium, which protects against abrasion.

• voice box

• connects the pharynx to the trachea

• keep food and liquid out of the airway and is involved in sound production.

helps prevent food and liquid from entering the airway during swallowing

Large cartilage of the larynx, often called the Adam’s apple.

sits inferior to the thyroid cartilage

• false vocal cords, They help protect the airway

• true vocal folds, produce sound when air passes through and causes them to vibrate.

• glottis is the opening between the vocal cords.

windpipe

• carries air from the larynx into the bronchial tree

  • open posteriorly so the esophagus can expand during swallowing.

  • posterior part of the trachea has smooth muscle and elastic connective tissue.

• carina = last trachea ring w sensory recptors that trigger cough

• trachea branches at carina to form L/R primary bronchi

• branching airway system inside the lungs

• bronchioles continue branching until they reach the respiratory zone.

  • Trachea → primary bronchi → secondary bronchi → tertiary bronchi → bronchioles → respiratory bronchioles → alveolar sacs

1,2,3, bronchioles then respiratory

• beginning of the respiratory zone

• 2/3 from terminal surrounded w thing smooth muscle bands

• lead to alveolar sacs(clusters of alveoli)

• start of gas exchange

• Alveoli are tiny air sacs where oxygen and carbon dioxide are exchanged between air and blood.

• alveolar sacs = clusters

Type I alveolar cells

• Type I alveolar cells are thin squamous cells. Their thinness allows rapid gas diffusion.

Type II alveolar cells

• produce surfactant to reduce surface tension + keep them open + not collapse, cuboidal

Alveolar macrophages

• phagocytize particles, debris,+ pathogens in alveoli

• thin barrier that gases must cross to move between the alveoli and pulmonary capillary blood.

  • Type I squamos alveolar cells

  • shared basal lamina

  • Capillary endothelial cell

• lungs serous membrane

  • Visceral pleura

    The visceral pleura is attached directly to the lung surface.

  • Parietal pleura

    The parietal pleura lines the inner wall of the thoracic cavity.

The potential space between the visceral and parietal pleurae

• contains pleural fluid, which reduces friction as the lungs move during breathing.

• breathing = inspiration/expiration

• pressure gradients

  • Gas moves from an area of higher pressure to lower pressure.

2-3 alveolar sacs 

respiratory membrane

prime mover 4 inpsiration

• When the diaphragm contracts, it moves downward, increasing thoracic cavity volume.

• This lowers intrapulmonary pressure and pulls air into the lungs.

  • When volume increases, pressure decreases.

  • When volume decreases, pressure increases.

boyle ^

• external intercostals assist with inspiration by helping expand the thoracic cage.

• internal intercostals are important during forced expiration.

If the airway diameter decreases, resistance increases and airflow decreases.

• pressure inside the pleural cavity

• slight vacuum between visceral and parietal pleurae

• normally lower than atmospheric pressure, creating a slight vacuum.

• helps keep the lungs expanded against the thoracic wall

  • if disrupted, the lung may collapse.

• Diaphragm contracts → thoracic volume increases

• causes intrapulmonary pressure to decrease below atmospheric pressure.

• air flows into lungs increasing lung volume

• → lung volume increases → intrapulmonary pressure decreases → air flows in

• Normal quiet exhalation is passive

• inspiratory muscles relax and the lungs recoil due to elastic tissue.

• Muscles relax → lung volume decreases → intra pressure increases above Atm → air flows out

• Forced exhalation uses muscles, like abdominal muscles and internal intercostals.

-air enters the pleural cavity.

-disrupts the normal intrapleural pressure/vacuum that holds the lung open.

-lungs collaspe risk

-bc it is no longer being pulled outward against the thoracic wall.

airway resistance, alveolar surface tension, and pulmonary compliance.

• A smaller airway diameter causes more resistance and less airflow.

• A larger airway diameter causes less resistance and more airflow.

airflow - controlled by the contraction or relaxation of the smooth muscles of the bronchioles

• Bronchodilation means the airways widen. This decreases resistance and increases airflow.

• Bronchoconstriction means the airways narrow. This increases resistance and decreases airflow.

• tension is caused by water molecules lining the alveoli

  • tension tends to pull the alveoli inward and could promote collapse.

• Surfactant from Type II alveolar cells reduces surface tension, making it easier for alveoli to stay open and for the lungs to expand.

ability of the lungs and the chest wall to stretch, a property known as distensibility ( not elasticity)

• Pulmonary compliance is how easily the lungs expand

• High compliance means the lungs expand easily.

• Low compliance means the lungs are stiff and harder to inflate

  • Restrictive lung diseases

• These are measured with a spirometer.

• TV = normal breath. IRV = extra in. ERV = extra out. RV = stuck air. VC = max usable exhale after max inhale. TLC = everything.

TV- 500mL

• amount of air inhaled or exhaled during a quiet breat

IRV

• extra air that can be inhaled after a normal tidal inhalation

• during forced inhalation.

ERV

-extra air that can be exhaled after a normal tidal exhalation

during forced exhalation

RV

-air remaining in the lungs after maximum exhalation

-This air cannot be voluntarily exhaled.

VC - 4700mL

-maximum amount of air that can be exhaled after a forced inspiration.

-the total amount of exchangeable air, or the total amount of air that can move in and out of the lungs. It is equal to the sum of the TV, IRV, and the ERV

TV + IRV + ERV

IC

the total amount of air that can be inhaled after a normal exhalation

IRV +TV

amount of air remaining in the lungs after a normal tidal exhalation.

the total amount of air the lungs can hold. 6000 mL.

exchangable + non

IRV, TV, ERV, and RV.

volume - green

capacity - blue+ longer

• Pulmonary gas exchange involves the exchange of gases between the alveoli and the blood

• Tissue gas exchange involves the exchange of gases between the blood in systemic capillaries and the body’s cells.

  Pulmonary ventilation brings new air into alveoli + removes oxygen-poor air from alveoli.

along their partial pressure gradients.

• A bigger pressure gradient increases the rate of exchange.

• A thicker respiratory membrane decreases gas exchange because gases must diffuse farther.

• A decreased surface area decreases gas exchange because there is less membrane available for diffusion.

fluid accumulation along the alveolar walls. This increases the distance gases must diffuse, so it -

• decreases the rate of gas exchange.

• alveolar walls break down.

• This decreases surface area available decreasing gas exchange,

• so oxygen and carbon dioxide exchange becomes less efficient.

Ventilation = airflow to alveoli. Perfusion = blood flow to alveoli.

• body match airflow + blood flow so gas exchange is efficient.

• No air? Move blood away. No blood? Move air away.

pulmonary arterioles constrict. This redirects blood away from poorly ventilated alveoli.

so rates matched

In areas with poor perfusion, bronchioles constrict. This redirects air away from areas that do not have good blood flow.

• between the alveoli and pulmonary capillary blood.

• In lungs, blood loads oxygen and unloads carbon dioxide.

• Oxygen moves from alveoli into blood bc alveolar PO₂ is higher than blood PO₂.

• Carbon dioxide moves from blood into alveoli because blood PCO₂ is higher than alveolar PCO₂.

• between systemic capillary blood and tissue cells.

• In the tissues, blood unloads oxygen and loads carbon dioxide to return

• Oxygen moves from blood into tissues because blood PO₂ is higher than tissue PO₂.

• Carbon dioxide moves from tissues into blood because tissue PCO₂ is higher than blood PCO₂.

Gas transport is the movement of oxygen and carbon dioxide through the blood.

• Most oxygen is transported bound to the 4 heme groups on hemoglobin inside erythrocytes.

  • four oxygen molecules can bind to one hemoglobin.

• A small amount of oxygen is dissolved in plasma (gas+solutes)

• Most carbon dioxide is transported as bicarbonate ion after carbonate ion dissolves

• CO₂ + H₂O → H₂CO₃ → HCO₃⁻ + H⁺

• This reaction is catalyzed by carbonic anhydrase, an enzyme found in red blood cells.

• Some carbon dioxide is dissolved in plasma or binds to the globin = carbaminohemoglobin

During loading, oxygen from alveoli binds to hemoglobin in the pulmonary capillaries.

• This loading reaction converts hemoglobin from deoxyhemoglobin (HHb) to oxyhemoglobin (HbO2).

During unloading, Hb in the systemic capillaries releases oxygen to the tissue cells.

Ventilation is controlled largely by groups of neurons in the brainstem.

• respiratory pattern generator helps generate the basic rhythm of breathing. RPG

• Ventral respiratory group

• dorsal respiratory group

  • Medulla oblongata controls breathing rate

• Medulla oblongata

RBG/ medulla oblongata set basic rhythym

• Central chemoreceptors monitor the pH of cerebrospinal fluid, or CSF.

• Blood CO₂ levels affect CSF pH bc CO₂ can combine w water to form carbonic acid, which dissociates into bicarbonate and hydrogen ions.

• More CO₂ leads to more H⁺, which lowers pH.

Decrease in rate/ depth of ventilation

• breathing rate decreases.

• to retain more co2 so when reacts w water forms carbonic acid that dissociates into H+ + bicarbonate ion

• neurons in the medullary reticular formation that detect ph changes in CSF

• located in the aortic bodies and carotid bodies + monitor blood ph, Partial p of O2 + CO2

  Central chemoreceptors check CSF pH. Peripheral chemoreceptors check blood gases and pH.

• If PCO₂ is high or H⁺ is high, breathing rate increases.

• This helps remove more CO₂ from the body. Removing CO₂ reduces carbonic acid formation and helps raise pH back toward normal.

• High CO₂/high H⁺ = breathe faster.

• They are especially important for detecting changes in oxygen levels in the blood.

  Peripheral chemoreceptors detect low O₂, high CO₂, or high H⁺ → signal medulla → breathing rate and depth increase.

Decrease pulmonary compliance

-reduce inspiration effectiveness + IC, TLC, VC

-lungs are harder to expand

cause: increased surface tension + destroyed eleastic fibers

• idiopathic pulmonary fibrosis - smoking , pneumoconiosis -toxins, neuromuscular disease, and chest wall deformities.

• make it harder to move air through the airways,

• due to airflow blockage or increased airway resistance

• decrease the efficiency of expiration

  Obstructive = airways blocked/narrowed. Problem getting air out.

  Asthma, chronic bronchitis, and emphysema

cleans the blood of metabolic wastes

-organs of excretion; that is, they remove wastes and water from the body

-essential for removing toxins, maintaining homeostasis of many variables (including blood pH and blood pressure), and producing erythrocytes.

Waste elimination

Regulates blood pressure, blood volume, osmolarity, and pH

Secretes renin and erythropoietin

removes metabolic wastes from the blood and eliminates them in urine. body cant use

• urea: nitrogenous waste product made from protein/amino acid metabolism. The kidneys filter urea from the blood so it can leave the body in urine.

kidneys and the urinary tract (bladder + urethra)

- transport, store, and eventually eliminate urine from the body.

filter the blood to remove metabolic wastes and then modify the resulting fluid producing urine.

Kidneys

• BP by controlling blood volume + releasing renin.

• Blood volume by deciding # water reabsorbed vs versus lost 2 urine.

• Osmolarity by controlling water + electrolyte balance, especially sodium and water.

• pH by controlling hydrogen ion secretion + bicarbonate ion reabsorption/excretion

• The kidneys secrete renin, which starts the RAAS pathway to raise blood pressure.

• The kidneys also secrete erythropoietin/EPO, which stimulates red blood cell production in red bone marrow when blood oxygen is low.

• kidney bean, in both shape and color

• Against the posterior abdominal wall and are retroperitoneal = behind organs

• right lower due to liver

Renal fascia, Adipose capsule, Renal capsule

-outer CT that anchors the kidney to surrounding structures/ abdominal wall

-middle fat that cushions the kidney + helps hold it in place.

-thin, deep connective tissue layer directly covering the kidney. It protects the kidney from trauma and infection.

cortex, medulla (pyramid )

-outer region contains renal corpuscles + < renal tubules. has a rich blood supply

-deeper/middle contains renal pyramids and nephron loops/collecting ducts.

renal cortex

lot of the tubules also present in this region

central cavity inside the kidney that contains urine-draining structures, blood vessels, nerves, and fat.

extensions of the renal cortex that project between renal pyramids. They contain blood vessels.

Renal pyramids are cone-shaped structures in the renal medulla. They contain many parallel tubules and collecting ducts.

The papilla is the tip of a renal pyramid. Urine drains from the papilla into a minor calyx.

papillary duct → minor calyx → major calyx → renal pelvis → ureter

In the kidney’s renal cortex, the interlobular arteries branch into tiny afferent arterioles

The afferent arteriole brings blood to the glomerulus.

The efferent arteriole carries/drains blood away from the glomerulus.

• to peritubular capillaries

ball of fenestrated g capillaries where blood filtration occurs.

-part of nephrons corpuscle

-allow water + solutes to leave blood easily

surround the renal tubules. They receive reabsorbed water and solutes from the tubule and can also deliver substances for secretion into the tubule.

• fed by efferent arteriole

capillaries associated with juxtamedullary nephrons.

They help maintain the medullary osmotic gradient without washing away solutes.

• As blood flows down into the medulla, it gains solutes and loses water.

• As blood flows back up toward the cortex, it loses solutes and gains water.

receives filtrate from multiple distal tubules. It helps determine final urine concentration, especially under the influence of ADH.

The papillary duct is the final portion of the collecting system. It drains urine into the minor calyx.

functional unit of the kidney. It filters blood, modifies filtrate, and helps produce urine.

Made of Renal corpuscle, tubule + can be cortical or juxtamedullar

The renal corpuscle is where filtration happens. It includes the glomerulus(capillaries) and the glomerular/Bowman capsule.

The glomerulus is the fenestrated capillary bed that filters plasma.

-surrounds the glomerulus and catches the filtrate that leaves the blood.

• parietal outer layer of glomerular capsule. made of simple squamous epi

• visceral layer made of podocytes, wrap around glomerular capillaries. w foot processes that form filtration slits

• capsular space = bt parietal + visceral layers. Filtrate enters this space after being filtered from blood

modifies filtrate through reabsorption and secretion.

• Proximal: 1st, longest, w micro villi bc does reabsorption.

• Distal tubule: after nephron loop. It has fewer microvilli than proximal tubule and is important for hormonally controlled reabsorption/secretion.

nephron loop is part of tubule

Descending limb move filtrate down into medulla; water permeable, so it leaves filtrate

• Thin: simple squamos; water

Ascending limb move filtrate up toward cortex; impermeable 2 water

pearmeable 2 solutes : Na, K, and Cl ions are moved out.

• Thick:cuboidal epithelium, transports ions

mostly located in the renal cortex

short nephron loops + are mainly associated with peritubular capillaries.

• renal corpuscles near the cortex-medulla border

• long nephron loops that extend deep into the medulla

• associated with the vasa recta and are important for producing concentrated urine.

  • help maintain the medullary osmotic gradien

1. Glomerular filtration Blood plasma is filtered from glomerulus into capsular space.

2. Tubular reabsorption Useful substances move from the tubule back into the blood.

3. Tubular secretion Substances move from the blood into the tubule to be eliminated.

barrier bt blood in the glomerulus and the capsular space. It allows water and small solutes to pass, but blocks blood cells, platelets, and most proteins

• fenestrated glomerular capillaries

• basal lamina; bt endothelial ^ + podocytes, neg charged + blocks proteins

• podocytes with filtration slits

• Increased blood pressure in the capillary pushes fluid + increases filtration

• If blood osmolarity is higher, blood has more solutes/proteins pulling water back into the capillaries by osmosis. This decreases filtration.

afferent arteriole dilates, increasing filtration

efferent arteriole constricts; Blood has trouble leaving the glomerulus, so pressure backs up and filtration increases.

glomerular filtration rate

• amount of filtrate formed by both kidneys per minute

high: filtrate 2 fast thru tubules. kidneys dont got time 2 reabsorb needed substances; may be lost in urine.

low: filtrate 2 slow. Too much reabsorbed; wastes may remain in blood or be reabsorbed instead of eliminated

Juxtaglomerular apparatus/JGA

composed of macula densa + juxtaglomerular cells

• regulates GFR + BP

– cells in the distal tubule that detect salinity NaCL of tubular fluid 

• salinity is an indicator of the rate of filtration (too much filtration = salty fluid) 

If filtration is too fast, less time is available for NaCl reabsorption, so tubular fluid reaching the macula densa is saltier.

• high salinity = GFR too high

• low salinity = GFR too low

JG cells

• modified smooth muscle cells in the walls of the afferent and efferent arterioles. They can help adjust arteriole diameter + they secrete renin.

• based on signals from macula densa cell

• If blood pressure/GFR is low, JG cells release renin to activate RAAS.

Water(drags) + solutes move from tubule to blood

• glucose, amino acids, sodium ions, chloride ions, bicarbonate ions

  • readily move into peritubular capillaries by osmosis and solvent drag 

proximal tubule reabsorbs the majority of filtered water and solutes.

• absorbs 100% of glucose

• sodium, bicarbonate, glucose, and amino acids.

sodium reabsorption creates gradient

• as sodium pumped(Na/K) out tubules cells to interstilial fluid = creates gradient

  • pull sodium out of filtrate and into cells

    • Cl, glucose w SLT transporter, water follows via osmosis - can drag others

• If blood glucose is too high, too much glucose is filtered.

  • Diabetes mellitus

• SGLT transporters can become saturated, meaning reach their transport maximum

• glycosuria:glucose cannot all be reabsorbed and glucose appears in the urine

Substances move from blood into tubule

Secretion helps

• remove wastes, drugs, toxins

  • ammonium ions, creatinine, uric acid, + other

• Aids in pH balance

  • secreting hydrogen ions into the filtrate

  • Removing H⁺ from the blood helps prevent blood from becoming too acidic.

water conservation

• higher osmolarity deeper in medulla = stronger pull for water to leave filtrate

• creates an osmotic gradient that pulls water out of the collecting duct when ADH is present.

• Salty renal medulla creates an osmotic gradient that pulls water out of the collecting duct when ADH is present.

Countercurrent multiplier establishes salinity gradient

• in the nephron loop of juxtamedullary nephrons. It creates the salty medullary gradient.

• Water leaves by osmosis(medulla is salty) bc descending limb permeable. Fluid = concentrated

• Water impermeable ascending limb, allows solutes(Na, K, Cl) to leave making medulla even more salty.

The concentrated medulla creates the osmotic gradient that pulls water out of the collecting duct when ADH is present, allowing the body to conserve water and make concentrated urine.

ADH inserts aquaporins into the collecting duct. Water then leaves the filtrate by osmosis because the medulla is highly concentrated. This makes urine more concentrated

When ADH is low or absent, few aquaporins are in the collecting duct. Water stays in the filtrate, so the urine remains dilute and more water is lost.

As water leaves the collecting duct, urea becomes concentrated in the filtrate. Some urea diffuses out into the medulla, adding to the osmotic gradient. Some reenters the nephron loop/proximal and cycles again, helping keep the medulla concentrated.

NaCl from the ascending limb and urea from the medullary collecting duct.

• The vasa recta helps supply blood to the medulla without washing away the salt gradient.

• The medulla needs blood supply, but if normal capillaries carried away all the salt, the kidney could not make concentrated urine. The vasa recta prevents that.

Low Osmolarity

• Dilute urine is produced when the body has excess water and needs to get rid of it.

• ADH not triggered so less aquaporin in CD

• Dilute urine after ascending limb;solutes left

• Less aquoporins in CD, allow less water to leave

• water stays in filtrate

High Osmolarity - Concentrated when water conservation needed

ADH triggered + inserts aquaporins into CD

water leaves via osmosis

high ADH = more aquaporins = more water reabsorbed = concentrated urine

Renin-Angiotensin-Aldosterone System/RAAS

• activated when BP, blood volume, Na levels low

• JG cells from Aferent arteriole release renin

• Renin converts angiotensinogen to angiotensin I

• ACE ( found in lungs endothelial)convert to AG- II

• Angiotensin II

Renin converts angiotensinogen to angiotensin I

ACE found in endothelial lungs converts I -> II

Increase BP!

• Vasoconstriction, increases peripheral resistance and raises blood pressure.

• stimulates the adrenal cortex to release aldosterone(increase sodium + water rention)

• promotes sodium reabsorption in proximal tubules

• stimulates the thirst center

• increased reabsorption of Na+ ions and increased secretion of K+ ions in the distal tubule/Collecting system 

• increased retention of water (water follows sodium ions) – less water in urine 

aldosterone = save Na⁺, lose K⁺, water follows Na⁺, BP rises

• The ureters transport urine from the kidneys to the urinary bladder.

• They use smooth muscle contractions called peristalsis to move urine.

stores urine

Detrusor muscle:Smooth muscle layer bladder wall.

• contracts during urination to push urine out.

trigone: smooth triangular region on bladder floor

• It is formed by the two ureter openings and the internal urethral orifice.

• It is formed by the two ureter openings and the internal urethral orifice.

smooth triangular region on bladder floor

The urethra carries urine from the urinary bladder to the outside of the body.

The internal urethral sphincter is smooth muscle and involuntary.

• point of trigone: right at bladder entrance

• Skeletal muscle and voluntary. This allows conscious control over urination

  outside of urethra

The external urethral orifice is the opening where urine exits the body.

pee hole

prostatic urethra — passes through the prostate membranous — short section thru pelvic floor spongy urethra — passes through the penis

Urination

Micturition means urination/voiding.

• bladder fills → stretch receptors fire → detrusor contracts → internal sphincter relaxes

• → external sphincter voluntarily relaxes → urine exits

• cortical collecting duct fine-tunes Na⁺, K⁺, H⁺, and water using hormones like aldosterone and ADH

• medullary collecting duct passes through salty medulla; with ADH, water leaves into medulla, making concentrated urine. Urea can also leave here and help maintain medullary osmotic gradient.

Ingestion, secretion, propulsion, digestion, absorption, defecation 

moving food through the tract. Examples: swallowing, peristalsis, mass movements, defecation.

• Defecation = elimination of indigestible material as feces.

Ingestion = taking food/liquid into the mouth.

Secretion = releasing substances into the GI tract, like saliva, mucus, acid, enzymes, bicarbonate, bile, and hormones. exo/endo

Digestion = breaking food down

• Mechanical

  • physically breaking food into smaller pieces w/o breaking bonds

    • mastication, stomach churning, segmentation, lipid emulsification

• Chemical

  • enzymes break bonds 4 nutrients thru hydrolysis

  • amylase breaks carbohydrates, pepsin/trypsin breaks proteins, lipase breaks triglycerides

digested nutrients, water, electrolytes, and vitamins move across the GI epithelium into blood or lymph.

AKA

alimentary canal/GI tract = the tube food passes through

• oral cavity → pharynx → esophagus → stomach → small intestine → large intestine → rectum/anal canal

help digestion but food usually does not pass through them

• teeth, tongue, salivary glands, liver, gallbladder, pancreas

Mucosa, submucosa, muscularis externa, serosa/adventiva

innermost layer touching the lumen of tract

3 parts!

• lined w epithelium:secretion/absorption

• Lamina propria: ct w blood vessels lymphatic tissue/MALT

• Muscularis mucosae: smooth

The 1st layer of the alimentary canal - mucosa ( 1/3 of its componets)

CT that contains blood vessels + tissue like MALT.

MALT is in the lamino propria of the mucosa layer of the alimentary canal

2nd part of canal

Connective tissue layer with blood vessels, lymphatic vessels, glands, and nerves. It supports the mucosa.

3 part of canal: w 2 smooth muscle layers

• Inner circular layer + outer longitudinal layer

• produces movement: peristalsis, segmentation, churning, sphincter control.

• outer layer for organs in the peritoneal cavity

  • is the visceral peritoneum + reduces friction

• Aventitia

  • outer connective tissue layer for organs not in the peritoneal cavity, like much of the esophagus. It anchors the organ to surrounding structures.

serous membrane of the abdominopelvic cavity.

• Parietal peritoneum lines the body wall

• Visceral peritoneum/serosa covers organs.

• Peritoneal cavity contains serous fluid to reduce friction.

Folds of peritoneum that hold digestive organs in place and carry blood vessels, nerves, and lymphatic vessels.

• Greater/Lesser omentum

• large fatty “apron” of peritoneum that hangs from the stomach over abdominal organs.

• Lesser omentum = smaller mesentery between the stomach and liver.

• digestive tract’s local nervous system

  • controls a lot of digestive motility + secretion through short reflexes

works with the ANS:

• Parasympathetic generally stimulates digestion.

• Sympathetic generally inhibits digestion

Labial frenulum = fold of mucosa connecting inside of the lips to the gums.

Vestibule = space between lips/cheeks and teeth/gums.

lined mostly with stratified squamous epithelium, which protects against abrasion from food.

= chewing.

• It mechanically breaks food into bolus/smaller pieces, increasing surface area for enzymes.

moist ball of chewed food mixed with saliva that is ready to be swallowed.

superior rood of mouth consisting of Hard palate + soft palate

Hard

• maxillae and palatine bones helps w mechanical digestion bc tongue can push food against it

Soft

• made of skeletal muscle.

• Uvula

  • Projection from soft palate

• Projection from the soft palate

• During swallowing, the soft palate and uvula move posteriorly/superiorly to help block food from entering the nasal cavity.

helps with mechanical digestion, taste, speech, and swallowing

• Lingual frenulum = fold that anchors the tongue to the floor of mouth.

• Papillae = projections on the tongue; some contain taste buds, and they help with friction during food manipulation.

Extrinsic muscles move the tongue as a whole. POSITIONs ex grande

Intrinsic muscles change the shape of the tongue. In SHAPE

Parotid glands = mostly watery/enzyme-rich saliva - BIG BUCCinator

Submandibular glands = produce most saliva; mixed serous and mucus Sublingual glands = mostly mucus-rich saliva

Saliva consists primarily of water; electrolytes such as sodium, chloride, and potassium ions; and variable amounts of mucus, depending on the type of salivary gland.

• Water = moistens food

• Mucus = lubricates bolus

• Salivary amylase = begins carbohydrate digestion

• Lysozyme and IgA = help protect against bacteria/pathogens

• Bicarbonate ions = help neutralize acid

• carbohydrate digestion

Enzyme begins chemical digestion of carbohydrates by breaking polysaccharides into smaller carbohydrates/oligosaccharides.

• involved in propulsion/swallowing of mucus lubricated bolus

• oropharynx and laryngopharynx

BT pharynx and esophagus. It relaxes during swallowing to allow the bolus to enter the esophagus.

• muscular tube posterior to trachea that moves the bolus to stomach w peristalsis(wave - like contractions)

• Stratified squamous nonkeratinized epi bc it needs protection from food abrasion

• Most of esophagus has adventitia bc not freely suspended in peritoneal cavity. Adventitia anchors it.

Opening in the diaphragm where the esophagus passes into the abdominal cavity to reach the stomach.

AKA gastroesophageal sphincter.

• It controls entry into the stomach + helps prevent acidic stomach contents from moving backward into the esophagus.

Deglutition - 3

1. Voluntary phase

2. Pharyngeal phase - involuntary

3. Esophageal phase

1. Voluntary phase

The tongue pushes the bolus posteriorly toward the oropharynx.

Involuntary. The bolus enters the oropharynx.

• The soft palate/uvula block the nasopharynx.

• The larynx elevates.

• The epiglottis helps cover the glottis so food does not enter the airway.

• The upper esophageal sphincter relaxes.

Peristalsis moves the bolus down the esophagus to the stomach.

Big idea: swallowing is about moving food down while protecting the airway.

Chyme = acidic, partially digested liquid mixture produced by stomach churning (mechanical) + chemical digestion.

Greater/Lesser curvature/ BODY

cardia = region where esophagus enters stomach

fundus = dome-shaped superior region

Pyloric region = distal + leading to small intestine (antrum + pyloric)

• Pyloric antrum

• Pylorus = terminal region near duodenum(1st part of small)

Controls movement of chyme from stomach into duodenum.

• Only a small amount of chyme exits at a time, about 3 mL, so the small intestine is not overwhelmed.

3ml of chyme through the pyloric sphincter into the small intenstine

Longitudinal, circular, and oblique - deep

• The extra inner oblique layer helps with strong churning/mixing.

simple columnar epithelium that secretes mucus.

• Mucous coat = barrier against acid/pepsin

• Tight junctions = prevent acid from leaking between epithelial cells

• Rapid epithelial replacement = damaged cells are replaced quickly

• Rugae = folds that allow the stomach to expand.

• Gastric pits = invaginations in the mucosa leading to gastric glands.

Pits lead to glands

• Mucous cells = secrete mucus for protection

• Enteroendocrine/DNES cells = secrete hormones like gastrin

• Parietal cells = secrete HCl + intrinsic factor

• Chief cells = secrete pepsinogen and gastric lipase

• Secreted by parietal cells in glands

• HCl creates acidic pH

• It helps activate pepsinogen into pepsin + kills many pathogens.

• Required for vitamin B12 absorption in the ileum.

• Secreted by parietal cells in gastric glands

• Inactive precursor released by chief cells.

  • HCl converts it into pepsin, which begins protein digestion.

• Secreted by chief cells of gastric glands

• Begins a small amount of lipid digestion.

= secrete hormones like gastrin

gastric lipase secreted by cheif cells

The small intestine is the major site of chemical digestion and absorption.

• MALT = peyers patch 4 immune

• Duodenum = first part; receives chyme, bile, and pancreatic juice

• Jejunum = main site of chemical digestion + absorption

• Ileum = final part; leads to large intestine

• Controls movement from ileum into cecum and prevents backflow from large intestine into small intestine.

big folds of the small intestine wall

= increase surface area + slow chyme

• smaller finger-like projections on the circular folds

• Each villus has

  • enterocytes = absorptive cells

  • goblet cells = mucus-producing cells

  • core with blood capillaries = absorb carbs/proteins into blood

  • lacteal = absorbs chylomicrons/lipids into lymph

tiny projections on the enterocytes cells of the villi

• Brush border = the fuzzy border made by the microvilli w enzymes

enzymes on/near the brush border that finish digestion, especially carbs and proteins

• Examples: lactase, maltase, sucrase, peptidases.

• glands between villi.

• They contain cells that secrete juice, mucus, hormones, + help replace epithelial cells.

• Intestinal juice

  • helps digestion and movement of chyme.

• Segmentation = mixing/churning + Peristalsis

Circular muscle contracts to mix/churn chyme with enzymes and bile.

• Absorb water + electrolytes

• Form and store feces

• Secrete mucus

• House bacterial flora

• Defecation

• simple columnar epi w many goblet cells

• Intestinal Crypts: glands w mucus-secreting cells

• Large intestine has lymphatic tissue bc it contains many bacteria + needs immune defense. MALT = appendix

• normal bacteria that

• Produce vitamins, especially vitamin K

• Metabolize undigested materials

• Help prevent harmful bacteria from growing

• Stimulate immune system development

• Cecum = first pouch of large intestine - 2 ileum

• Appendix = lymphatic tissue, attached 2 cecum

• Ascending colon, Transverse colon

• Descending colon, Sigmoid colon(END)

• Rectum, Anal cana

Taenia coli = 3 bands of longitudinal smooth muscle

• tension creates pouch-like sacs called haustra.

• Internal anal sphincter = smooth muscle, involuntary.

• External anal sphincter = skeletal muscle, voluntary

• right next 2 each other internal IN

Haustral contractions = due 2 contractions of circular muscle, slow mixing contractions that help absorb water/electrolytes.

Mass movements = stronger peristaltic movements that push feces toward rectum.

contain indigestible material, bacteria, water, mucus, and waste products.

Endocrine = releases hormones into blood, like insulin and glucagon

Exocrine = releases digestive secretions into ducts

• acinar cells: secrete digestive enzymes in ducts

• These ducts carry pancreatic juice to the duodenum - 1st part of small intestine

• Exocrine function by acinar cells^

• Sodium bicarbonate = neutralizes acidic chyme

  • NaHCO3

• Enzymes = digest carbohydrates, proteins, lipids, and nucleic acids

the hormones cholecystokinin (CCK) and secretin 

CCK = enzymes + bile release

Secretin = bicarbonate for acid

• Release triggered when proteins/lipids enter duodenum

• Effect

  • stimulates pancreatic enzyme secretion + gall bladder contraction 4 = bile release

Released triggered by chyme(acidic) entrance to duodenum

Effect: stimulates bicarbonate secretion from pancreatic ducts + increases bile production

• Larger Right lobe

  • Caudate lobe - behind right lobe

• Left lobe

• Quadrate lobe(small near Gallbladder)

Separates right and left lobes and anchors liver to anterior abdominal wall.

Functional units of the liver.

• Central vein

• Hepatic sinusoids

• Hepatocytes

• Hepatic triads

Leaky capillaries where blood flows slowly past hepatocytes so materials can be exchanged.

RIVERS

liver cells

• absorb glucose + other nutrients from the blood after digestion  

• removes + degrades hormones, toxins and drugs 

• produces albumin + clotting factors then secretes them into the blood 

• glycogenolysis (glycogen to glucose)

• urea after amino acid breakdown

  Make

• nonessential aminos

• lipoproteins

Liver lobule corner:

Hepatic artery branch = brings oxygen-rich blood

arteriole

Hepatic portal vein branch = brings nutrient-rich blood from digestive organs - venule

Bile ductule = carries bile away

Brings nutrient-rich blood from digestive organs

Blood flows toward central vein. thru sinosoids

Bile flows away from hepatocytes toward bile ductules

Bile is important for fat digestion because bile acids/salts emulsify lipids.

Bile acids/salts

Bilirubin ( waste into bile)+ Water + electrolytes

Cholesterol + wastes

• Helps remove excess cholesterol through bile

• Produces urea after amino acid breakdown

• Produces nonessential amino acids

• Synthesizes plasma proteins like albumin and clotting factors

• Produces bile

• Detoxifies alcohol and drug

The gallbladder stores and concentrates bile.

Cystic Duct

• Carries bile to and from the gallbladder.

Bile Release

• Stimulated by CCK - 2 cause gallbladder contration

Right and left hepatic ducts → common hepatic duct

gallbladder - Cystic duct

mouth - carbs

Salivary amylase breaks polysaccharides into smaller carbs.

breaks polysaccharides into smaller carbs

breaks polysaccharides into oligosaccharides

All monosaccharides enter capillaries in intestinal villi and travel through the hepatic portal vein to the liver.

Protein digestion starts in the stomach.

• Pepsinogen is released by chief cells.

• HCl activates pepsinogen into pepsin.

• Pepsin begins breaking proteins into smaller peptides

• pepsin - released as pepsinogen from stomach 

• trypsin - released as trypsinogen from pancreas 

• prevent premature digestion

Trypsin. inactive form released by pancrease. a protease

• Brush border enzymes finish breaking peptides into amino acids.

• Amino acids enter enterocytes, then enter capillaries in intestinal villi, then go to the liver through the hepatic portal vein.

• Lingual lipase = starts minor lipid digestion, mostly more important in infants

• Gastric lipase = begins lipid digestion in stomach

• Pancreatic lipase = main lipid-digesting enzyme in small intestine

mechanical digestion of fat into smaller droplets.

• Bile acids/salts do this.

emulsification does not chemically digest fat. It just breaks big fat globules into smaller droplets so lipase has more surface area to work on.

• Carry digested lipids from the intestinal lumen to the absorptive enterocyte.

• They carry things like fatty acids, monoglycerides, cholesterol, and fat-soluble vitamins.

Triglycerides are packaged into chylomicrons.

• Chylomicrons are too large to enter blood capillaries.

• Chylomicrons enter lacteals, which are lymphatic capillaries in the villus into lymphatic system then blood stream

after micells bring digested lipids

• Free fatty acids and monoglycerides are rebuilt into triglycerides.

• then packeged into chylomicrons

Carbs/proteins → blood capillaries → hepatic portal vein → liver

Lipids → lacteals/lymph → blood later

A, D, E, K - Fatty lives in the attic

• They require fat for absorption because they are absorbed with lipids in micelles

• fat digestion/absorption is impaired, fat-soluble vitamin absorption can also decrease

B complex + C

They dissolve in water and are absorbed differently than fats.

• Important special case: Vitamin B12 must bind 2 intrinsic factor from stomach parietal cells + is absorbed in the ileum

Body balances water gain/loss

• Water is important because it transports solutes, regulates temperature, cushions organs, and lubricates tissues.

• Fluid maintained throguh 2 compartments.

• Intracellular fluid, ICF = fluid inside cells, mostly cytosol.Main ion inside cells: K⁺

• Extracellular fluid, ECF = fluid outside cells. This includes interstitial fluid and plasma.Main ions outside cells: Na⁺ and Cl⁻.

• Plasma and interstitial fluid are both ECF, but plasma has more proteins.

• That matters because plasma proteins help create colloid osmotic pressure, which pulls water into blood.

water moves toward the side with more solute / higher osmolarity.

water follows solute

• how one fluid affects water movement compared with another fluid.

• iso, hyper, hypo

• Same solute concentration

  • no water movement

• Hypotonic - swells

  • lower solute concentration

• Hypertonic - shrivels

  • high solute concentration

Hypothalamus

• through osmoreceptor 4 plasma

• Dehydration → osmolarity increases → hypothalamic osmoreceptors detect it → thirst

• Angiotensin II and decreased blood volume/blood pressure can also stimulate thirst.

• ADH causes the kidneys to retain water by inserting aquaporins into the distal tubule and collecting duct/system.

• ADH controls water output independently of sodium.

High ADH → more water reabsorbed → less urine → concentrated urine → water retention

it retains water indirectly by retaining sodium first

• ADH = water channels directly.

• Aldosterone = Na⁺ reabsorption first, then water follows Na⁺.

total body water decreases and ECF osmolarity increases

• thirst, shrink cell, low bp/v,

Overhydration = total body water increases + ECF osmolarity decreases

• cell swell

hyponatremia, meaning low sodium concentration due to dilution.

increased interstitial fluid

• usually isosomotic

• caused by high HP

  • pushing fluid out of capillary

    • Hypertension, + Na

• Low blood osmP

  • less protein 2 pull water in

    • liver disease

  • impaired lympnodes

Too much fluid pushed out, not enough fluid pulled back in, or lymph can’t drain it.

• ICF: mostly K⁺

• ECF: mostly Na⁺ and Cl⁻

mainly ecf

• resting membrane potentials/depolarization

• therefore muscle (including heart) + nervous function 

• aldosterone, ANP

Aldosterone saves sodium. ANP dumps sodium.

Mainly ICF

• RMP, repolarization, muscle/heart + nervous

• Aldosterone

• Aldosterone saves sodium. ANP dumps sodium.

• So aldosterone lowers blood potassium.

mainly ECF

• depends on sodium

• follows

important for skeleton

• muscle contraction

• second messenger system for hormones,

• exocytosis (important for neuronal synapses)

• blood clotting 

• PTH, calcitrol, calcitonin

PTH - secreted when levels low , increase bone release, dietary via vit D activation

Calcitriol / vitamin D₃

• increases calcium absorption from the small intestine, dietary + absorp P

• Calcitonin

  • lowers blood calcium by encouraging calcium deposition into bone

pH measures hydrogen ion concentration.

7.35–7.45

pH does not directly change because sodium or other ions change unless those ions bind or release hydrogen ions.

Buffers resist changes in pH.

in blood

more h+ = low ph = acidic

These are organ systems:

• respiratory system - quicker

• urinary system - effective

• weak acid + conjugate base

• bicarbonate buffer system

• phosphate buffer system

• protein buffer system

CO₂ + H₂O ⇌ H₂CO₃ ⇌ HCO₃⁻ + H⁺

carbon dioxide + water ⇌ carbonic acid

• High H+ ions, bicarbonate bind to H+ ions to keep the pH stable (equation pushed left) 

• Low H+ ion , equation pushed right (which releases hydrogen ions), helping to keep the hydrogen ion concentration (and pH) stable 

too acidic in the body, H+ too high respiratory system can rid the body of carbon dioxide by breathing faster. decreasing potential carbonic acid formed.

hypo:breathing rate can be slowed if conditions become too basic (alkaline) 

increases the amount of carbon dioxide that is breathed off, and more carbon dioxide breathed off makes conditions less acidic in the body 

• secretion of hydrogen ions to be excreted in urine

• reabsorption of bicarbonate ions 

• Kidneys remove H⁺ and save HCO₃⁻ when body is too acidic.

  retain H⁺ and secrete/excrete HCO₃⁻. when to basic

pH below 7.35

• This means there is too much H⁺ or too little bicarbonate.

Ineffective ventilation → CO₂ builds up → carbonic acid increases → H⁺ increases → pH decreases

• hypoventilation, airway obstruction, poor gas exchange

• renal compensation. by secreted H+ absorbing HCO3

acid problem not primarily caused by CO₂

• Excess acid production: ketones, loss of bases; direhea, or kidney not reabsorbing bicarbonate; base loss or acid gain

• Respiratory compensation or urinary(if not prob)

Hyperventilation blows off CO₂ → lowers carbonic acid → lowers H⁺ → raises pH

Alkalosis = pH above 7.45.

This means there is too little H⁺ or too much bicarbonate/base.

Hyperventilation → too much CO₂ lost → carbonic acid decreases → H⁺ decreases → pH increases

compensation: → The urinary system compensates by decreasing H⁺ secretion and decreasing HCO₃⁻ reabsorption, so more bicarbonate is lost in urine.

• excessive antacids

• prolonged vomiting, because stomach acid/H⁺ is lost; acid loss or base gain

• Respiratory compensation: hypoventilates

  • Hypoventilation retains CO₂ → increases carbonic acid → increases H⁺ → lowers pH

• Renal compensation: retain H+, secrete HCO3

• gonads are the primary sex organs.

• Their job is to produce gametes and sex hormones.

• male: testes/testicles: spermatozoa/sperm; testosterone

• female:ovaries:oocytes/ova:estrogens, progesterone, inhibin,

meiosis, not mitosis

Meiosis reduces chromosome number from 46 chromosomes/23 pairs to 23 chromosomes so fertilization can restore the normal diploid number.

Humans have 46 chromosomes arranged in 23 pairs.

XX = female

XY = male

Y chromosome contains the SRY gene

• which triggers development of testes

• to produce testosterone to support male reproductive tract

two duct systems

• . If testosterone is present, the male ducts develop and the female ducts degenerate.

• If testosterone is absent, the female ducts develop.

body changes that develop at puberty due to rising sex hormones.

-pubic, facial, axillary hair 

• voice changes (males), breast development (females) 

• male:increased muscle mass, increased bone density, thicker skin, and increased RBC production

• testes begin development in the abdominopelvic cavity

• descend into the scrotum.

• gubernaculum shortens and helps pull the testes downward

• pass through the inguinal canal.

• This matters because sperm production requires a temperature a few degrees lower than core body temperature.

• perineum is the diamond-shaped region bounded by the

• pubic symphysis anteriorly, ischial tuberosities laterally, and coccyx posteriorly

• Male external genitalia include the penis and scrotum.

pouch containing the testes. It protects them and helps regulate temperature.

contains structures traveling to and from the testis

• Ductus deferens — carries sperm

• Testicular artery — brings blood to testes

• Pampiniform venous plexus — cools arterial blood before it reaches testes

• Lymphatics — drainage

• Testicular nerves

• Cremaster muscle — raises/lowers testes

raises/lowers testes for temperature regulation

in cord

— cools arterial blood before it reaches testes

site of sperm production - Spermatogenesis

• interstitial cells between tubules produce testosterone 

• sustentacular cells aid in sperm development 

Testes contain many internal lobules with seminiferous tubules.

• spermatic cord

• scrotum

• spermatogonia = diploid STEM cells 

• primary spermatocytes undergo meiosis I to = 2 haploid secondary spermatocytes 

• each secondary spermatocyte undergoes meiosis II to give rise to two haploid spermatids  

• four haploid spermatids - genetic variation + new allele combos

• product of meiosis is four haploid spermatids – each with 23 chromosomes  

• the spermatids have genetic variation, new combinations of alleles 

differentiates into a primary spermatocyte.

meiosis I, producing two haploid secondary spermatocytes.

= spermatids mature into spermatozoa 

• shed excess cytoplasm,

• develop a flagellum/tail,

• form an acrosome over the nucleus,

• move mitochondria into the midpiece.

Seminiferous tubules → straight tubules → rete testis → efferent ductules → epididymis → ductus deferens → ejaculatory duct → urethra → external urethral orifice

Epididymis: Site of sperm maturation and storage

Ductus deferens: Transports sperm from epididymis toward pelvic cavity

• ampulla – wide portion at the terminal end 

Ejaculatory duct

• Forms where ductus deferens meets seminal vesicle

• passes through prostate gland + empties into the urethra

Urethra

Transports semen out of the body through the penis. In males, the urethra is part of both the urinary and reproductive systems.

Accessory glands add fluid to sperm to make semen.

seminal vesicle, prostate, bulbourethral

Paired glands that empty into the ejaculatory ducts. They contribute a large portion of seminal fluid.

seminal vesicle

Surrounds the urethra inferior to the bladder. It secretes a thin/milky fluid.

• secretes thin, white secretion  

Paired glands near the base of the penis.

• secrete a small amount of alkaline mucus-like lubricating fluid that helps lubricate

Semen = sperm + seminal fluid (fluid from seminal vesicles and prostate gland) 

• Fructose = sperm fuel

• prostaglandins – chemical messengers for the female 

  • Affect female reproductive tract/mucus/contractions

• bicarbonate neutralizes acidic conditions in the vagina 

• root = internal portion 

• shaft = external portion 

• glans = terminal portion 

• prepuce = foreskin 

engorge with blood during erection 

• corpus spongiosum – encloses spongy urethra

• corpora cavernosa  - paired

HPG axis

GnRH

FSH - Sustentacular cells = ABP + inhibin.

• stimulates release of androgen-binding protein (ABP) –it binds androgens (testosterone)  supports

LH - stimulates interstitial cells = testosterone.

Testosterone : spermatogenesis + 2nd

inhibin: Released by sustentacular cells inhibits FSH

• androgen-binding protein (ABP) –it binds androgens (testosterone) 

• ABP keeps testosterone in the tubule, stimulating spermatogenesis 

• outer region is the ovarian cortex, where follicles and oocytes develop.

• The inner region is the ovarian medulla, which contains blood vessels, lymphatics, and nerves.

ovarian cortex

release of a secondary oocyte from the ovary

The uterine tubes/fallopian tubes receive the ovulated oocyte and move it toward the uterus.

• Fimbriae — fingerlike projections that help “catch” the ovulated secondary oocyte.

site of implantation and supports development during pregnancy. If pregnancy does not occur, the uterus sheds menstrual fluid.

• Fundus — rounded superior region

• Body — main portion

• Cervix — inferior neck that opens into vagina

From superficial to deep by anatomy:

Perimetrium — outer serous layer

Myometrium — thick smooth muscle layer

Endometrium — inner mucosal lining

Stratum functionalis — thickens and sheds during menstruation.

Stratum basalis — remains after menstruation and rebuilds the stratum functionalis.

receives the penis/semen during intercourse, provides a passageway for menstrual flow, and acts as the birth canal.

• hymen is an incomplete mucosal fold near the vaginal opening

• stratified squamous epithelium to protect against friction. It has an acidic environmen

collective term for external female genitalia.

mons pubis

labia majora, labia minora ,clitoris

vestibule, vestibular glands, prepuce of clitoris

The clitoris contains erectile tissue and is homologous to erectile tissue in the penis.

modified sweat glands. Their function is milk production after pregnancy.

• Areola — pigmented skin around nipple

production of the female gamete.

• It begins before birth, pauses, resumes at puberty, and ends at menopause.

Oogonia divide by mitosis and become primary oocytes.

prophase I MEOSIS I

BEFORE BIRTH

Each month, a group/cohort of follicles is stimulated. Usually one primary oocyte completes meiosis I.

• one large secondary oocyte + one small polar body

• BEGIN

• secondary oocyte begins meiosis II but arrests in metaphase II.

MEIOSIS II /metaphase II

Ovulation=

-Usually one secondary oocyte is ovulated each month.

The secondary oocyte only completes meiosis II if fertilized. Then it forms: 1 ovum + second polar body

one functional ovum and polar bodies.

Spermatogenesis makes 4 functional sperm.

Oogenesis makes 1 functional ovum + 1-3 polar bodies.

follicle development in the ovary

secondary oocyte = ovum + polar bodies 1 or 3

1st step of follicgeneis

present at birth; primary oocyte surrounded by one layer of follicular cells.

Tertiary/vesicular follicle — large fluid-filled antrum forms; mature follicle develops.

mature follicles – only one develops each month 

= ovulation

forms from ruptured follicle after ovulation; secretes progesterone and some estrogen.

scar tissue remnant if pregnancy does not occur and corpus luteum degenerates.

The sexual cycle includes the ovarian cycle and the uterine cycle. They happen at the same time and are coordinated by hormones.

• Follicular = day 1-14 

  • Fol growth, produce estrogen , trigger LH

• Ovulation ~ day 14 

  • release secondary oocyte + cells 

  • triggered by LH surge

• Luteal = day 15 – 28 

• luteum secretes progesterone ~estrogen

• (hormone levels drop at end of phase due to corpus luteum involution forming corpus albicans) 

Menstrual = 1-5 , 6-14proliferative phase, secretory 15-28

• days 1–5

• The uterus sheds the stratum functionalis, producing menstrual fluid from the vagina.

• This happens because estrogen and progesterone levels are low after the corpus luteum degenerates.

days 6–14

The stratum basalis rebuilds the stratum functionalis.

This is stimulated mainly by estrogen from developing follicles.

Endometrial glands and spiral arteries grow.

Ovulation occurs at the end of this phase.

• endometrium thickens and becomes secretory.

• Endometrial glands secrete glycogen-rich fluid/uterine milk to prepare for implantation.

• stimulated mainly by progesterone from corpus luteum.

If no pregnancy, corpus luteum involutes

progesterone drop = menstration