Overview of Anatomy & Physiology 2

Respiratory System
- Main functions: gas exchange (O2 and CO2), regulation of blood pH, and olfaction.
- Key structures: nasal cavity, pharynx, larynx, trachea, bronchi, lungs (alveoli).
- Mechanism of breathing: inhalation (diaphragm contraction) and exhalation (relaxation of diaphragm).
Cardiovascular System
- Components: heart, blood vessels (arteries, veins, capillaries), and blood.
- Heart anatomy: chambers (atria, ventricles), valves (atrioventricular, semilunar).
- Blood circulation: systemic and pulmonary circuits; cardiac cycle (systole and diastole).
Digestive System
- Main functions: intake of food, digestion (mechanical and chemical), absorption of nutrients, elimination of waste.
- Major organs: mouth, esophagus, stomach, small and large intestines, liver, pancreas.
- Processes: peristalsis, enzymatic breakdown, nutrient absorption via villi.
Urinary System
- Main functions: regulation of body fluids, electrolyte balance, waste removal.
- Key structures: kidneys (nephrons), ureters, bladder, urethra.
- Processes: filtration (glomerulus), reabsorption, secretion, and excretion.
Endocrine System
- Functions: hormone production, regulation of metabolism, growth, and homeostasis.
- Major glands: pituitary, thyroid, adrenal, pancreas, reproductive glands.
- Hormonal pathways: feedback mechanisms (negative and positive feedback).
Nervous System
- Divisions: central nervous system (CNS) and peripheral nervous system (PNS).
- Neuron structure: dendrites, cell body, axon, synapse.
- Functions: sensory input, processing, motor output; reflex arcs.
Immune System
- Main functions: defense against pathogens, signaling for immune response.
- Components: white blood cells (B cells, T cells), lymphatic system, antibodies.
- Immune responses: innate (immediate) and adaptive (specific), memory cell formation.
Reproductive System
- Male structures: testes, spermatic ducts, prostate, penis; hormone: testosterone.
- Female structures: ovaries, fallopian tubes, uterus, vagina; hormones: estrogen, progesterone.
- Reproductive processes: gametogenesis, fertilization, gestation, lactation.

Integration of Systems

Homeostasis: systems work together to maintain stable internal conditions.
Interdependence: for example, respiratory and cardiovascular systems collaborate for gas exchange.
Feedback loops: maintain equilibrium in physiological processes, such as blood glucose regulation between the endocrine and digestive systems.

Clinical Relevance

Pathophysiological changes can affect multiple systems; understanding interactions is essential for treatment.
Common diseases: asthma (respiratory), hypertension (cardiovascular), diabetes (endocrine), chronic kidney disease (urinary).

Study Strategies

Use diagrams to visualize structures and processes.
Practice with flashcards to memorize key terms and functions.
Engage in group discussions to reinforce material through teaching and questioning.

Respiratory System

Primary function: Gas exchange of oxygen and carbon dioxide.
Other functions: Regulating blood pH and facilitating sense of smell (olfaction).
Key structures: Nasal cavity, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi, lungs.
Lungs, the primary site of gas exchange: Contain tiny air sacs called alveoli.
Breathing Mechanism:
- Inhalation: Diaphragm contracts, increasing thoracic cavity volume and drawing air in.
- Exhalation: Diaphragm relaxes, decreasing thoracic cavity volume and expelling air.

Cardiovascular System

Components: Heart, blood vessels (arteries, veins, capillaries), and blood.
Heart: A four-chambered pump responsible for circulating blood.
- Chambers: Two atria (upper chambers) and two ventricles (lower chambers).
- Valves: Atrioventricular valves prevent backflow between atria and ventricles, and semilunar valves prevent backflow from ventricles into arteries.
Blood Circulation:
- Systemic circulation: Blood travels from the heart to the body and back.
- Pulmonary circulation: Blood travels from the heart to the lungs and back.
Cardiac Cycle: Repeated sequence of contractions and relaxations of the heart.
- Systole: Contraction phase when heart pumps blood.
- Diastole: Relaxation phase when heart fills with blood.

Digestive System

Primary function: Breakdown of food into smaller molecules for absorption.
Other functions: Ingestion of food, nutrient absorption, elimination of waste.
Major organs: Mouth, esophagus, stomach, small and large intestines, liver, pancreas.
Processes:
- Peristalsis: Wave-like muscular contractions that move food through the digestive tract.
- Enzymatic breakdown: Chemical digestion using enzymes to break down complex molecules.
- Nutrient absorption: Primarily occurs in the small intestine via villi, finger-like projections that increase surface area.

Urinary System

Primary Functions:
- Regulation of body fluids: Maintaining proper water balance.
- Electrolyte balance: Controlling the levels of salts and minerals in the body.
- Waste removal: Eliminating metabolic byproducts and excess substances.
Key structures: Kidneys, ureters, bladder, urethra.
Kidneys:
- Nephrons: Functional units of the kidneys where filtration, reabsorption, secretion, and excretion take place.
Processes:
- Filtration: Blood is filtered in the glomerulus (capillary network) of each nephron.
- Reabsorption: Useful substances are reabsorbed from the filtrate back into the blood.
- Secretion: Waste products are secreted from the blood into the filtrate.
- Excretion: The remaining waste (urine) passes through the ureters, bladder, and urethra for elimination.

Endocrine System

Function: Production and secretion of hormones that regulate various bodily functions.
Major Glands: Pituitary gland, thyroid gland, adrenal glands, pancreas, and reproductive glands.
Hormonal Pathways: Hormones travel through the bloodstream to target cells.
- Feedback Mechanisms:
  - Negative feedback: Counteracts changes, maintaining homeostasis (e.g., blood glucose control by insulin).
  - Positive feedback: Amplifies changes, often involved in rapid processes (e.g., childbirth).

Nervous System

Divisions:
- Central Nervous System (CNS): Brain and spinal cord.
- Peripheral Nervous System (PNS): Nerves connecting the CNS to the rest of the body.
Neuron Structure:
- Dendrites: Receive signals from other neurons.
- Cell body: Contains the nucleus and other cellular machinery.
- Axon: Transmits signals away from the cell body.
- Synapse: Junction between the axon of one neuron and the dendrite of another.
Functions:
- Sensory input: Receive information about the environment.
- Processing: Integrate and analyze information.
- Motor output: Send signals to muscles and glands to produce responses.
- Reflex Arcs: Fast, involuntary responses to stimuli.

Immune System

Primary Function: Defend against pathogens (disease-causing organisms).
Other functions: Removing waste products, signaling for immune responses.
Components:
- White blood cells: Lymphocytes (B cells and T cells) and other immune cells.
- Lymphatic system: A network of vessels and tissues that help transport immune cells and fluid.
- Antibodies: Proteins that bind to specific antigens on pathogens, marking them for destruction.
Immune Responses:
- Innate immunity: Non-specific, immediate defenses (e.g., skin, phagocytic cells).
- Adaptive immunity: Specific, targeted defenses (e.g., antibody production, T cell-mediated responses).
- Memory cell formation: Immune cells that remember previous pathogens, providing faster and stronger responses upon re-encounter.

Reproductive System

Male Reproductive System:
- Structures: Testes (produce sperm), spermatic ducts, prostate gland, penis.
- Hormone: Testosterone (responsible for male sexual characteristics).
Female Reproductive System:
- Structures: Ovaries (produce eggs), fallopian tubes, uterus, vagina.
- Hormones: Estrogen and progesterone (regulate female reproductive cycle).
Reproductive Processes:
- Gametogenesis: Production of gametes (sperm and eggs).
- Fertilization: Union of sperm and egg.
- Gestation: Development of the fetus in the uterus.
- Lactation: Production of milk by the mammary glands after childbirth.

Integration of Systems

Homeostasis: Maintaining stable internal conditions through the coordinated actions of all body systems.
Interdependence: Organ systems work together, often relying on each other to function effectively.
- Example: Respiratory and cardiovascular systems collaborate for gas exchange (O2 delivery and CO2 removal).
Feedback Loops: Help maintain equilibrium in physiological processes.
- Blood glucose regulation: The endocrine system (insulin and glucagon) interacts with the digestive system to control blood sugar levels.

Clinical Relevance

Pathophysiological changes: Disruptions in the normal functioning of systems.
Importance of understanding inter-system interactions: Understanding how disease or injury in one system can affect other systems is crucial for diagnosis and treatment.
Common Diseases:
- Asthma (respiratory): Disorder of the airways, affecting breathing.
- Hypertension (cardiovascular): High blood pressure, affecting heart function and blood vessel health.
- Diabetes (endocrine): Disorder of blood sugar regulation, affecting multiple systems.
- Chronic kidney disease (urinary): Progressive loss of kidney function, affecting fluid balance and waste removal.

Study Strategies

Visualization: Use diagrams and illustrations to understand the structure and function of organs and systems.
Flashcards: Create flashcards to learn and remember key terms, definitions, and functions.
Active Learning: Engage in group discussions, practice explaining concepts to others, and ask clarifying questions.