BIOL 252: Human Anatomy & Physiology II - Structured Study Notes

Course Overview: Human Anatomy & Physiology II

Introduction

This course is the second in a sequence covering human anatomy and physiology, focusing on the circulatory, lymphatic, respiratory, digestive, urinary, and reproductive systems. It emphasizes mechanisms, case studies, and laboratory components to provide experiential learning and real-world applications.

Blood Composition and Hemostasis

Blood Components and Functions

Blood is a connective tissue composed of plasma and formed elements (erythrocytes, leukocytes, platelets). It serves critical functions in transport, regulation, and protection.

• Plasma: The liquid matrix of blood, containing water, proteins, nutrients, hormones, and waste products.

• Erythrocytes (Red Blood Cells): Specialized for oxygen transport via hemoglobin.

• Leukocytes (White Blood Cells): Involved in immune defense and response.

• Platelets: Cell fragments essential for blood clotting (hemostasis).

Hemostasis is the process that prevents and stops bleeding, involving vascular spasm, platelet plug formation, and coagulation.

• Vascular Spasm: Immediate constriction of blood vessels after injury.

• Platelet Plug Formation: Platelets adhere to exposed collagen and aggregate.

• Coagulation: Cascade of clotting factors leading to fibrin mesh formation.

Diagnostic Blood Tests: Used to assess blood composition and detect disorders. Common tests include complete blood count (CBC), hematocrit, and blood typing.

Blood Typing: Determines ABO and Rh blood groups, crucial for transfusions.

Key Equations:

• Hematocrit calculation: $\text{Hematocrit} = \frac{\text{Volume of RBCs}}{\text{Total Blood Volume}} \times 100$

Cardiovascular System: The Heart

Heart Anatomy and Physiology

The heart is a muscular organ responsible for pumping blood throughout the body. It consists of four chambers (two atria, two ventricles) and is divided by valves that ensure unidirectional flow.

• Microscopic Anatomy: Cardiac muscle fibers are striated, branched, and interconnected by intercalated discs for synchronized contraction.

• Heart Valves: Include atrioventricular (tricuspid, bicuspid/mitral) and semilunar (pulmonary, aortic) valves.

• Cardiac Cycle: Sequence of events in one heartbeat, including systole (contraction) and diastole (relaxation).

• Electrical Conduction: Involves the sinoatrial (SA) node, atrioventricular (AV) node, bundle of His, and Purkinje fibers.

ECG (Electrocardiogram): Records the electrical activity of the heart. Key components include the P wave, QRS complex, and T wave.

• P wave: Atrial depolarization

• QRS complex: Ventricular depolarization

• T wave: Ventricular repolarization

Cardiac Output Equation:

• $\text{Cardiac Output} = \text{Heart Rate} \times \text{Stroke Volume}$

Factors Affecting Heart Function: Physical activity, autonomic nervous system, metabolic demands, and pathological conditions.

Cardiovascular System: Blood Vessels

Structure and Function of Blood Vessels

Blood vessels transport blood throughout the body and are classified as arteries, veins, and capillaries.

• Arteries: Carry blood away from the heart; thick muscular walls.

• Veins: Return blood to the heart; thinner walls, contain valves.

• Capillaries: Microscopic vessels for exchange of gases, nutrients, and wastes.

Blood Pressure: The force exerted by blood on vessel walls. Measured in mmHg.

• Systolic pressure: Pressure during ventricular contraction.

• Diastolic pressure: Pressure during ventricular relaxation.

Key Equation:

• $\text{Blood Pressure} = \text{Cardiac Output} \times \text{Total Peripheral Resistance}$

Capillary Exchange: Movement of substances between blood and tissues via diffusion, filtration, and osmosis.

Regulation of Blood Flow: Influenced by vessel diameter, blood viscosity, and local metabolic needs.

The Lymphatic System and Immunity

Lymphatic Vessels and Immune Response

The lymphatic system returns interstitial fluid to the bloodstream and is integral to immune defense.

• Lymphatic Vessels: Network of vessels transporting lymph, filtered through lymph nodes.

• Lymph Nodes: Sites of immune cell activation and filtration of pathogens.

• Primary Lymphoid Organs: Bone marrow and thymus (site of lymphocyte development).

• Secondary Lymphoid Organs: Spleen, lymph nodes, tonsils (site of immune response).

Innate Immunity: Non-specific defense mechanisms (skin, mucous membranes, phagocytes).

Adaptive Immunity: Specific responses involving lymphocytes (B cells and T cells) and antibody production.

Respiratory System

Structure and Function

The respiratory system enables gas exchange, supplying oxygen and removing carbon dioxide.

• Major Organs: Nose, pharynx, larynx, trachea, bronchi, lungs.

• Alveoli: Site of gas exchange via diffusion.

• Respiratory Muscles: Diaphragm and intercostal muscles facilitate ventilation.

Gas Exchange Equation:

• $\text{O}_2 + \text{Hb} \rightleftharpoons \text{HbO}_2$

Pathological States: Disorders such as asthma, COPD, and pneumonia affect respiratory function.

Digestive System

Structure and Physiology

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

• Major Organs: Mouth, esophagus, stomach, small intestine, large intestine, liver, pancreas.

• Digestive Processes: Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, defecation.

Enzymatic Breakdown: Enzymes such as amylase, protease, and lipase facilitate digestion.

Physiological Processes: Peristalsis, secretion of digestive juices, absorption of nutrients.

Urinary System

Structure and Function

The urinary system maintains homeostasis by regulating fluid balance, electrolyte concentration, and waste removal.

• Major Organs: Kidneys, ureters, bladder, urethra.

• Nephron: Functional unit of the kidney, responsible for filtration and reabsorption.

Regulation of Concentration and Volume: Achieved through hormonal control (ADH, aldosterone) and renal mechanisms.

Key Equation:

• $\text{Glomerular Filtration Rate (GFR)} = \frac{\text{Urine Concentration} \times \text{Urine Flow Rate}}{\text{Plasma Concentration}}$

Reproductive System

Anatomy and Physiology

The reproductive system ensures species continuity through gamete production and fertilization.

• Male Reproductive System: Testes, epididymis, vas deferens, seminal vesicles, prostate, penis.

• Female Reproductive System: Ovaries, fallopian tubes, uterus, vagina.

• Spermatogenesis: Process of sperm cell development in the testes.

• Oogenesis: Process of egg cell development in the ovaries.

Hormonal Regulation: Involves FSH, LH, estrogen, progesterone, and testosterone.

Summary Table: Major Systems and Key Functions

System	Main Organs	Key Functions
Circulatory	Heart, blood vessels, blood	Transport, regulation, protection
Lymphatic	Lymph nodes, vessels, spleen, thymus	Fluid balance, immune defense
Respiratory	Lungs, trachea, bronchi, alveoli	Gas exchange, pH regulation
Digestive	Stomach, intestines, liver, pancreas	Digestion, absorption, waste elimination
Urinary	Kidneys, bladder, ureters, urethra	Excretion, fluid/electrolyte balance
Reproductive	Testes, ovaries, uterus, penis, vagina	Gamete production, fertilization

Additional info: These notes expand on the course outline and module objectives, providing academic context and definitions for key terms and processes relevant to Anatomy & Physiology II.