Overview
This lecture introduces the foundational concepts of anatomy and physiology, focusing on terminology, structural organization, organ systems, characteristics of life, homeostasis, anatomical positions, and basic medical imaging.
Introduction to Anatomy and Physiology
- Anatomy studies the structure of body parts and their relationships.
- Physiology is the study of the functions of body parts.
- Gross anatomy examines structures visible to the naked eye; microscopic anatomy studies structures only visible with a microscope.
- Microscopic anatomy is subdivided into cytology (cells) and histology (tissues).
- Gross anatomy can be regional (specific regions), surface (external features), or systemic (body systems).
Levels of Structural Organization
- Levels: Chemical (atoms, molecules), Cellular (organelles, cells), Tissue (groups of similar cells), Organ (two or more tissues), Organ System (organs working together), Organism (all systems combined).
- Cell theory: cells are the basic unit of life, all life is cellular, and cells come from pre-existing cells.
Overview of the 11 Organ Systems
- Lymphatic: protects against infection, transports lymph, absorbs fats.
- Respiratory: gas exchange (Oâ‚‚ and COâ‚‚), lungs, trachea, nasal passages.
- Muscular: movement, support, heat production.
- Nervous: communication, immediate responses via the brain, spinal cord, nerves.
- Integumentary: skin, hair, nails for protection and temperature regulation.
- Skeletal: bones for support, movement, blood cell formation, mineral storage.
- Endocrine: hormone-secreting glands for long-term regulation.
- Cardiovascular: heart, blood, vessels for nutrient/waste transport.
- Digestive: intake, breakdown, absorption of food, waste elimination.
- Urinary: kidneys, bladder for waste removal, pH, and fluid balance.
- Reproductive: organs for production of gametes and hormones.
Characteristics and Requirements of Life
- Responsiveness: sense/respond to stimuli.
- Growth and development: increase in size/number of cells.
- Reproduction: produce offspring.
- Movement: move body or internal fluids/materials.
- Respiration: exchange of Oâ‚‚ and COâ‚‚.
- Circulation: movement of fluids (blood).
- Digestion: breakdown and absorption of food.
- Excretion: removal of metabolic waste.
- Metabolism: includes anabolic (building) and catabolic (breaking) reactions.
- Requirements: oxygen, nutrients, narrow temperature range, atmospheric pressure.
Homeostasis and Feedback Mechanisms
- Homeostasis: maintenance of stable internal conditions.
- Controlled by feedback mechanisms: negative feedback opposes changes (temperature regulation); positive feedback amplifies changes (childbirth, blood clotting).
- Homeostatic control has three components: receptor (sensor), control center, effector.
Anatomical Terminology and Position
- Anatomical position: standing upright, feet parallel, palms forward.
- Prone: lying face down; Supine: lying face up.
- Directional terms: anterior (front), posterior (back), superior (top), inferior (bottom), medial (midline), lateral (side), proximal (closer), distal (farther), superficial (surface), deep (internal).
- Sectional planes: sagittal (left/right), midsagittal (midline), parasagittal (off midline), frontal/coronal (front/back), transverse (top/bottom), oblique (diagonal).
Body Cavities and Membranes
- Dorsal cavity: cranial (brain), vertebral (spinal cord).
- Ventral cavity: thoracic (pleural, mediastinum), abdominal, pelvic.
- Serous membranes: double-layered, parietal (body wall), visceral (organ), with serous fluid between layers.
Abdominopelvic Regions and Quadrants
- Four quadrants: RUQ, LUQ, RLQ, LLQ with specific organs in each.
- Nine regions: umbilical, epigastric, hypogastric, right/left hypochondriac, lumbar, iliac regions.
Medical Imaging Overview
- X-ray: imaging bones.
- CT scan: detailed cross-sectional images.
- MRI: uses magnetic fields for soft tissues.
- PET scan: visualizes activity/blood flow.
- Ultrasound: uses sound waves, safe for pregnancy.
Key Terms & Definitions
- Gross Anatomy — study of body structures visible to the naked eye.
- Microscopic Anatomy — study of structures too small to see unaided.
- Homeostasis — maintaining a stable internal environment.
- Negative Feedback — response that reverses a change in a controlled condition.
- Positive Feedback — response that enhances a change in a controlled condition.
- Anatomical Position — standard body orientation for terminology.
- Serous Membrane — double-layered membrane with fluid, lining body cavities.
Action Items / Next Steps
- Learn major organs and functions of each of the 11 organ systems.
- Study all anatomical terms, roots, prefixes, and suffixes.
- Review tables and diagrams of body regions, quadrants, and directional terms.