ANP Midterm Study Guide: Key Concepts and Systems

Blood and Circulatory System

Hemorrhage

Hemorrhage refers to the loss of blood from the circulatory system, which can occur internally or externally. It is a critical condition that can lead to hypovolemic shock if not managed promptly.

• Key Point: Severe hemorrhage reduces blood pressure and oxygen delivery to tissues.

• Example: Trauma resulting in arterial bleeding.

Blood Types and Transfusion Compatibility

Blood types are classified based on the presence of antigens (A, B, AB, O) and Rh factor. Compatibility is crucial for safe transfusions.

• Universal Donor: Type O negative can donate to any blood type.

• Universal Recipient: Type AB positive can receive from any blood type.

Blood Type	Can Donate To	Can Receive From
O-	All types	O-
AB+	AB+	All types
A+	A+, AB+	A+, A-, O+, O-
B+	B+, AB+	B+, B-, O+, O-

Blood Clotting (Hemostasis)

Hemostasis is the process that stops bleeding and involves three main phases.

• Vascular Spasm: Immediate constriction of blood vessels.

• Platelet Plug Formation: Platelets adhere to the site and aggregate.

• Coagulation: Formation of a fibrin mesh stabilizing the plug.

Phases of Hemostasis

• Vascular spasm

• Platelet plug formation

• Coagulation

Blood Components

• Albumin: Maintains osmotic pressure.

• Globulins: Alpha, beta, and gamma globulins function in transport and immunity.

• Fibrinogen: Essential for clot formation.

Blood pH

The normal average pH range of blood is 7.35–7.45.

Velocity of Blood Flow

Blood flow velocity is highest in arteries and lowest in capillaries, allowing for efficient exchange of gases and nutrients.

Factors Influencing Blood Pressure

• Cardiac output

• Peripheral resistance

• Blood volume

• Vessel elasticity

Arteriolar Blood Pressure

Increased by vasoconstriction, increased cardiac output, and higher blood volume.

Blood Flow Resistance

Most significant source is the diameter of arterioles.

Blood Disorders

• Pernicious anemia: Vitamin B12 deficiency.

• Aplastic anemia: Bone marrow failure.

• Sickle cell anemia: Abnormal hemoglobin.

• Polycythemia: Excess RBCs.

Blood Distribution Functions

• Transport of oxygen, nutrients, hormones, and waste.

• Regulation of temperature, pH, and fluid volume.

• Protection against infection and blood loss.

Heart and Cardiac System

Cardiac Muscle and Blood Supply

Cardiac muscle requires a constant blood supply for oxygen and nutrients. Deprivation leads to ischemia, angina pectoris, or myocardial infarction.

• Example: Blockage of coronary arteries causes heart attack.

Conduction System of the Heart

The heart's conduction system coordinates contraction.

• Sinoatrial (SA) node

• Atrioventricular (AV) node

• AV bundle (Bundle of His)

• Bundle branches

• Purkinje fibers

Electrocardiogram (ECG) Waves

• P wave: Atrial depolarization

• QRS complex: Ventricular depolarization

• T wave: Ventricular repolarization

Cardiac Cycle and Heart Sounds

• First heart sound (S1): Closure of AV valves

• Second heart sound (S2): Closure of semilunar valves

Left Ventricular Wall Thickness

The left ventricular wall is thicker than the right because it pumps blood throughout the systemic circulation, requiring more force.

Absolute Refractory Period in Cardiac Muscle

Longer than in skeletal muscle to prevent tetanus and ensure rhythmic contractions.

Heart Block

Damage to the AV node or bundle can cause heart block, disrupting electrical conduction.

ANP Synthesis

Atrial Natriuretic Peptide (ANP) is synthesized in the atria of the heart and regulates blood pressure by promoting sodium excretion.

Blood Vessels

Types and Functions

• Arteries: Carry blood away from the heart.

• Veins: Return blood to the heart.

• Arterioles: Regulate blood flow and pressure.

• Capillaries: Sites of gas and nutrient exchange.

• Venules: Collect blood from capillaries.

Structure of Blood Vessels

• Tunica intima: Inner layer

• Tunica media: Smooth muscle layer

• Tunica externa (adventitia): Outer connective tissue

Respiratory System

Pulmonary Circulation

Pulmonary circulation carries deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium.

Respiratory Control Centers

Located in the medulla oblongata and pons of the brainstem.

Gas Exchange Mechanism

Oxygen and carbon dioxide exchange in the lungs occurs by diffusion across the alveolar-capillary membrane.

Lung Volumes and Capacities

• Tidal volume: Amount of air inhaled or exhaled in a normal breath.

• Inspiratory capacity: Maximum amount of air inhaled after a normal exhalation.

• Expiratory reserve volume: Additional air exhaled after normal exhalation.

• Vital capacity: Total amount of air that can be exhaled after maximal inhalation.

Lung Compliance

Determined by elasticity of lung tissue and surface tension in alveoli.

Type I and II Alveolar Cells

• Type I: Form the alveolar wall, allow gas exchange.

• Type II: Secrete surfactant to reduce surface tension.

Intrapulmonary Pressure

Pressure within the alveoli; changes during breathing to allow air movement.

Air Movement in Lungs

• Air moves into lungs when intrapulmonary pressure drops below atmospheric pressure.

• Air moves out when intrapulmonary pressure rises above atmospheric pressure.

Gas Laws

• Boyle's Law: $P_1V_1 = P_2V_2$ (Pressure and volume are inversely related)

• Charles' Law: $V \propto T$ (Volume is proportional to temperature)

• Dalton's Law: Total pressure is sum of partial pressures.

• Henry's Law: Gas solubility in liquid is proportional to partial pressure.

Carbon Dioxide Transport

• Most CO2 is carried as bicarbonate ions in plasma.

• Equation: $CO_2 + H_2O \rightarrow H_2CO_3 \rightarrow H^+ + HCO_3^-$

Lymphatic and Immune System

Lymphatic Structures

• Lymph nodes: Filter lymph.

• Lymph follicles: Contain immune cells.

• Lymphatics: Vessels transporting lymph.

• Thymus, tonsil, Peyer's patch, appendix: Lymphatic organs.

Lymph Transport

Involves movement through lymphatic vessels, aided by skeletal muscle contraction and valves.

Immunocompetence

The ability of lymphocytes to recognize and respond to antigens.

Antibodies (Immunoglobulins)

• IgG: Most abundant, crosses placenta.

• IgA: Found in mucosal areas.

• IgM: First produced in response.

• IgE: Allergic responses.

• IgD: B cell receptor.

Primary Immune Response

Initial response to antigen exposure, slower and less robust than secondary response.

Passive Immunity

Acquired by receiving antibodies from another source (e.g., maternal antibodies).

Complete Antigens

Substances that provoke a full immune response and have immunogenicity and reactivity.

Interferon Role

Proteins produced by cells in response to viral infection; inhibit viral replication and activate immune cells.

Phagocytosis Sequence

• Chemotaxis

• Adherence

• Ingestion

• Digestion

• Exocytosis

Cells Involved in Immunity

• T lymphocytes: Cell-mediated immunity.

• B lymphocytes: Antibody-mediated immunity.

• Plasma cells: Produce antibodies.

• Neutrophils, eosinophils, monocytes, basophils: Types of white blood cells.

• Megakaryocyte: Platelet precursor.

• Hemocytoblast: Stem cell for blood cells.

• Polymorphonuclear cell: Neutrophil.

Structures Draining Lymph

The right lymphatic duct drains lymph from the right upper limb, right side of head, and thorax.

Functions of Lymphatic System

• Fluid balance

• Absorption of fats

• Immune defense

Endocrine System

Hormones and Their Actions

• Aldosterone: Regulates sodium and water balance.

• Epinephrine: Fight-or-flight response.

• Estrogen: Female reproductive hormone.

• Renin: Regulates blood pressure.

• Angiotensinogen: Precursor to angiotensin.

• Secretin, leptin, gastrin: Various digestive and metabolic functions.

Hormone Mechanisms

• Protein or amino acid-based hormones: Act via second messenger systems (e.g., cAMP, Ca2+).

• Steroid hormones: Act via direct gene activation in the nucleus.

Second Messenger Mechanism

Hormone binds to receptor, activates G protein, which stimulates production of second messenger (e.g., cAMP).

Factors for Target Cell Activation

• Hormone concentration

• Number of receptors

• Affinity of receptor for hormone

Posterior Pituitary Gland

Not a true endocrine gland; stores and releases hormones produced by the hypothalamus.

Special Senses

Eye Anatomy and Function

• Aqueous humor: Fluid in anterior chamber.

• Cornea: Transparent front part.

• Lens: Focuses light.

• Iris: Controls pupil size.

• Order of light passage: Cornea → aqueous humor → lens → vitreous humor → retina.

• Rod cells: Responsible for vision in dim light.

• Cone cells: Responsible for color vision.

• Ganglion, bipolar cells: Transmit visual signals.

Dark Adaptation

Process by which eyes adjust to low light conditions, primarily involving rod cells.

Conscious Perception of Vision

Reflects activity in the visual cortex of the occipital lobe.

Equilibrium and Hearing

• Maculae: Essential for static equilibrium.

• Utricle, cochlear duct, semicircular canals: Structures involved in balance and hearing.

• Receptors for hearing: Located in the cochlea.

Olfactory and Taste Buds

Olfactory cells are stimulated by odorants; taste buds are stimulated by dissolved chemicals.

• Fungiform papillae: Contain taste buds.

• Basal cells: Regenerate taste cells.

• Gustatory hairs: Detect taste stimuli.

Other Key Concepts

Static Equilibrium

Maintained by the maculae in the vestibular system.

Fluid Balance Across Capillary Walls

Reflected by the net filtration pressure, which determines direction and amount of fluid movement.

Hypertension Consequences

Can result in damage to blood vessels, heart, kidneys, and increased risk of stroke.

Parathyroid Gland Mechanisms

Maintains blood calcium levels by releasing parathyroid hormone (PTH), which increases calcium release from bones, absorption in intestines, and reabsorption in kidneys.

Reproductive System

Follicle Stimulating Hormone (FSH) is essential for spermatogenesis; deficiency can lead to infertility.

Fetal Circulation

• Ductus arteriosus: Becomes ligamentum arteriosum at birth.

• Foramen ovale: Becomes fossa ovalis at birth.

Cellular Affinity, Stressor Reaction, Up Regulation

• Cellular affinity: Strength of binding between receptor and hormone.

• Stressor reaction: Body's response to stress, often involving hormone release.

• Up regulation: Increase in receptor number in response to hormone.

Second Messenger Ions

Calcium ions (Ca2+) can act as second messengers for amino acid-based hormones.

Peripheral Resistance

Resistance to blood flow in peripheral vessels, mainly arterioles.

Platelets

Cell fragments essential for blood clotting.

Functional Characteristics of WBCs

• Phagocytosis

• Antibody production

• Inflammatory response

Inflammatory Response

Body's defense mechanism involving redness, heat, swelling, and pain.

Chemotaxis, Diapedesis, Phagocytosis

• Chemotaxis: Movement toward chemical signals.

• Diapedesis: WBCs moving through vessel walls.

• Phagocytosis: Engulfing pathogens.

Adaptive and Innate Immunity

Natural killer cells can kill cancer and virus-infected cells before activation of adaptive immunity.

Gas Exchange Sites

Main sites are alveoli in the lungs.

Balance of Fluid Across Capillary Walls

Determined by hydrostatic and osmotic pressures.

Sequence of Events in Phagocytosis

• Recognition

• Attachment

• Engulfment

• Digestion

• Exocytosis

Hormone Receptor Interaction

Activation depends on hormone concentration, receptor number, and affinity.

Distributing Functions of Blood

• Transport of gases, nutrients, waste

• Regulation of pH, temperature

• Protection against pathogens

Components of Lymph

• Water

• Proteins

• White blood cells

• Fatty acids

Order of Light Passage Through Eye

• Cornea

• Aqueous humor

• Lens

• Vitreous humor

• Retina

Summary Table: Key Blood Cells

Cell Type	Function
Neutrophil	Phagocytosis of bacteria
Eosinophil	Combat parasites, allergies
Monocyte	Phagocytosis, become macrophages
Basophil	Release histamine
Megakaryocyte	Produce platelets
Hemocytoblast	Stem cell for all blood cells

Summary Table: Gas Laws

Law	Statement
Boyle's Law	Pressure and volume are inversely related ($P_1V_1 = P_2V_2$)
Charles' Law	Volume is proportional to temperature ($V \propto T$)
Dalton's Law	Total pressure is sum of partial pressures
Henry's Law	Gas solubility in liquid is proportional to partial pressure

Additional info: Academic context and explanations have been added to brief points for completeness and clarity.