Comprehensive Study Guide: Anatomy & Physiology II (Chapters 16–27) Learning Objectives

Unit 1: The Endocrine, Cardiovascular, and Lymphatic Systems

Chapter 16: The Endocrine System

The endocrine system is a collection of glands that secrete hormones to regulate bodily functions. It works closely with the nervous system to maintain homeostasis.

• Hormone: A chemical messenger secreted into the blood that acts on distant target cells.

• Infundibulum: The stalk connecting the hypothalamus to the pituitary gland, allowing communication between the nervous and endocrine systems.

• Endocrine vs. Nervous System:

  • Endocrine: Slow, long-lasting effects via hormones in the bloodstream.

  • Nervous: Rapid, short-term effects via electrical impulses and neurotransmitters.

  • Similarity: Both maintain homeostasis and use chemical messengers.

• Neuroendocrine Organs: Organs like the hypothalamus and adrenal medulla that release hormones in response to neural signals.

• Major Structures: Hypothalamus, pituitary, thyroid, parathyroid, adrenal glands, pancreas, pineal gland, and gonads.

• Hormone Classes:

  • Amino acid-based hormones: Bind to cell surface receptors; act via second messengers.

  • Steroid hormones: Lipid-soluble; cross cell membranes and bind intracellular receptors.

• Stimuli for Secretion: Humoral (blood levels), neural (nerve fibers), hormonal (other hormones).

• Pituitary Gland:

  • Anterior: Glandular tissue; produces and releases hormones.

  • Posterior: Neural tissue; stores and releases hypothalamic hormones.

• Hypothalamic-Hypophyseal Portal System: Network of blood vessels connecting hypothalamus to anterior pituitary for hormone transport.

• Glucagon & Insulin: Antagonistic hormones from the pancreas regulating blood glucose.

Tables to Review:

• Table 16.1: Hypothalamus & Pituitary Hormones

• Table 16.2: Thyroid & Parathyroid Hormones

• Table 16.3: Adrenal Gland Hormones

• Table 16.4: Other Endocrine Organs

Chapter 17: The Heart

The heart is a muscular organ that pumps blood through two circuits: pulmonary (lungs) and systemic (body).

• Blood Flow: Blood enters atria from veins and exits ventricles via arteries.

• Pulmonary Circuit: Right side pumps blood to lungs; returns to left atrium.

• Systemic Circuit: Left side pumps blood to body; returns to right atrium.

• Heart Wall Layers:

  • Epicardium: Outer layer (connective tissue).

  • Myocardium: Middle layer (cardiac muscle).

  • Endocardium: Inner layer (endothelial tissue).

• Coronary Sinus: Delivers deoxygenated blood from myocardium to right atrium.

• Blood Pathway: Systemic capillaries → venae cavae → right atrium → right ventricle → pulmonary arteries → lungs → pulmonary veins → left atrium → left ventricle → aorta → systemic capillaries.

• Cardiac Conduction: SA node → AV node → AV bundle → bundle branches → Purkinje fibers.

• Pacemaker Cells: SA node, AV node, Purkinje fibers; differ in location and rate.

• Plateau Phase: Prolongs action potential, prevents tetanus.

• ECG Waves: P, QRS, T, U, PR interval; represent electrical events.

• Heart Sounds: S1 (AV valves close), S2 (semilunar valves close).

• Cardiac Cycle Phases: Filling, contraction, ejection, relaxation.

• Volumes:

  • EDV: End-diastolic volume (pre-contraction).

  • ESV: End-systolic volume (post-contraction).

  • Stroke Volume: $SV = EDV - ESV$

  • Cardiac Output: $CO = SV \times HR$

Chapter 18: Blood Vessels

Blood vessels transport blood throughout the body and regulate blood pressure and flow.

• Three Tunics:

  • Tunica externa: Connective tissue (outermost).

  • Tunica media: Smooth muscle (middle).

  • Tunica intima: Endothelium (innermost).

• Blood Flow & Pressure: Directly proportional to pressure gradient; inversely to resistance.

• Blood Pressure Factors: Cardiac output, blood volume, peripheral resistance.

• Mean Arterial Pressure: $MAP = \frac{1}{3} (SBP - DBP) + DBP$

• Capillary Types: Continuous, fenestrated, sinusoidal; differ in permeability.

• Hydrostatic Pressure: Drives water out of capillaries; higher at arterial end.

• Colloid Osmotic Pressure: Draws water into capillaries; due to plasma proteins.

Unit 2: Blood, Lymphatic, and Immune Systems

Chapter 19: Blood

Blood is a connective tissue with multiple functions, including transport, regulation, and protection.

• Blood Composition (centrifuged):

  • Plasma: ~55%

  • Buffy coat (leukocytes & platelets): <1%

  • Erythrocytes: ~45%

• Functions: Transport gases/nutrients, immune defense, clotting, pH regulation.

• Plasma Proteins: Albumin (osmotic pressure), globulins (immunity), fibrinogen (clotting); produced in liver.

• Erythrocytes: Biconcave, no nucleus, lifespan ~120 days.

• Key Terms: Hematocrit, erythropoiesis, hematopoiesis, HSCs, leukopoiesis.

• Erythropoiesis: Formation of RBCs; regulated by erythropoietin (EPO).

• Leukocytes: Five types; granulocytes (neutrophils, eosinophils, basophils), agranulocytes (lymphocytes, monocytes).

• Platelets: Cell fragments from megakaryocytes; involved in clotting.

• Hemostasis: Five steps: vascular spasm, platelet plug, coagulation, clot retraction, clot removal.

• Blood Types: Determined by antigens (A, B, Rh); O- universal donor, AB+ universal recipient.

Chapter 20: Lymphatic System and Immunity

The lymphatic system returns interstitial fluid to the blood and provides immune defense.

• Lymphatic Capillaries: More permeable than blood capillaries; absorb interstitial fluid.

• Lymph Nodes: Filter lymph; house immune cells.

• Main Functions: Fluid balance, fat absorption, immune response.

• Immunity: Innate (nonspecific) vs. adaptive (specific); three lines of defense.

• Antibodies: Five classes (IgG, IgA, IgM, IgE, IgD); functions include agglutination, opsonization, neutralization.

• Active vs. Passive Immunity: Active (body produces antibodies), passive (antibodies received).

Unit 3: Respiratory and Digestive Systems, Metabolism

Chapter 21: Respiratory System

The respiratory system enables gas exchange and regulates blood pH.

• Major Structures: Nasal cavity, pharynx, larynx, trachea, bronchi, lungs.

• Zones: Conducting (air movement), respiratory (gas exchange).

• Respiratory Processes: Pulmonary ventilation, gas exchange, transport, tissue exchange.

• Boyle's Law: $P_1V_1 = P_2V_2$

• Respiratory Volumes: TV, IRV, ERV, RV; capacities are combinations of volumes.

• Gas Transport: Oxygen (bound to hemoglobin), CO2 (dissolved, as bicarbonate, bound to Hb).

• Hyperventilation: Decreases CO2, increases pH (alkalosis).

• Hypoventilation: Increases CO2, decreases pH (acidosis).

Chapter 22: Digestive System

The digestive system breaks down food, absorbs nutrients, and eliminates waste.

• Major Functions: Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, defecation.

• Alimentary Canal Layers: Mucosa, submucosa, muscularis externa, serosa/adventitia.

• Accessory Organs: Teeth, tongue, salivary glands, liver, gallbladder, pancreas.

• Motility: Peristalsis (propulsion), segmentation (mixing).

• Stomach Phases: Cephalic, gastric, intestinal; regulate secretion and motility.

• Small Intestine: Duodenum, jejunum, ileum; main site of absorption.

• Liver: Produces bile; gallbladder stores bile.

Chapter 23: Metabolism and Nutrition

Metabolism includes all chemical reactions in the body, divided into catabolism (breakdown) and anabolism (synthesis).

• ATP: Main energy currency; hydrolysis is highly exergonic.

• Glycolysis: Anaerobic; produces 2 net ATP per glucose.

• Citric Acid Cycle & ETC: Aerobic; produce most ATP.

• Glycogenesis: Formation of glycogen from glucose.

• Glycogenolysis: Breakdown of glycogen to glucose.

• Gluconeogenesis: Formation of glucose from non-carbohydrate sources.

• Hormonal Regulation: Insulin (anabolism), glucagon (catabolism).

Unit 4: Urinary, Fluid/Electrolyte, Reproductive, and Developmental Systems

Chapter 24: Urinary System

The urinary system removes waste and regulates fluid, electrolyte, and acid-base balance.

• Organs: Kidneys, ureters, bladder, urethra.

• Kidney Regions: Cortex, medulla, pelvis.

• Nephron: Functional unit; renal corpuscle (glomerulus + capsule), renal tubule.

• Urine Formation: Filtration, reabsorption, secretion.

• GFR: Glomerular filtration rate; affected by arteriole diameter and pressures.

• Hormonal Regulation: RAAS, ADH, ANP.

• Micturition: Reflex and voluntary control of urination.

Chapter 25: Fluids, Electrolytes, and Acid-Base Homeostasis

Body fluid balance is essential for cellular function and homeostasis.

• Electrolytes: Dissociate into ions; nonelectrolytes do not.

• Fluid Compartments: Intracellular, extracellular.

• Water Movement: Driven by hydrostatic and osmotic pressures.

• Acid-Base Balance: Maintained by buffers, respiratory, and renal mechanisms.

• pH: Acidic (<7), neutral (7), basic (>7).

• Disorders: Metabolic/respiratory acidosis/alkalosis.

Chapter 26: The Reproductive System

The reproductive system produces gametes and enables fertilization and development.

• Gonads: Testes (sperm), ovaries (ova).

• Meiosis: Produces haploid gametes; increases genetic variability.

• Spermatogenesis: Sperm production in seminiferous tubules.

• Oogenesis: Ova production; begins before birth, completes at fertilization.

• Hormonal Regulation: FSH, LH, estrogens, progesterone.

• Ovarian/Uterine Cycles: Follicular, ovulation, luteal; menstrual, proliferative, secretory phases.

Chapter 27: Development and Heredity

Development covers prenatal and postnatal changes; heredity explains genetic inheritance.

• Prenatal Periods: Pre-embryonic, embryonic, fetal.

• Fertilization: Sperm meets oocyte; prevents polyspermy.

• Embryonic Development: Gastrulation (germ layers), organogenesis.

• Placenta: Nutrient/gas exchange; barrier to some substances.

• Genetics: Chromosome, gene, allele, genotype, phenotype, codominance, sex-linked inheritance.

Additional info:

• Tables and figures referenced (e.g., Table 16.1, Figure 17.8) should be reviewed in the textbook for detailed hormone lists, pathways, and visual summaries.

• Key equations are provided in LaTeX format for clarity and exam preparation.