Overview
This lecture introduces the fundamentals of anatomy and physiology, including structural organization, body systems, basic life processes, homeostasis, anatomical terminology, body planes, cavities, and membranes.
Introduction to Anatomy and Physiology
- Anatomy studies body structure; physiology studies body functions.
- "Ana" means apart, "tomy" means to cut.
- Systemic anatomy studies by systems; regional by areas; surface by external features; imaging uses technology.
Levels of Structural and Functional Organization
- Chemical level: atoms and molecules (e.g., DNA, glucose).
- Cellular level: basic units of life; cytology is the study of cells.
- Tissue level: groups of similar cells; histology is the study of tissues.
- Four tissue types: epithelial, connective, muscle, and nervous.
- Organ level: two or more tissues working together (e.g., stomach, heart).
- System level: groups of organs with a common function (e.g., digestive system).
- Organism level: complete living being, single or multicellular.
Major Body Systems and Their Functions
- Nervous: regulates body activities with nerve impulses.
- Digestive: breaks down food, absorbs nutrients, eliminates wastes.
- Cardiovascular: circulates blood, delivers oxygen/nutrients, removes waste.
- Respiratory: gas exchange, regulates acid-base balance.
- Reproductive: gamete production, hormone secretion.
- Urinary: eliminates waste, maintains blood composition.
- Lymphatic: returns fluids, immunity.
- Skeletal: support, movement, mineral storage, blood cell production.
- Muscular: movement, posture, heat production.
- Integumentary: protection, temperature regulation, sensation.
- Endocrine: regulates bodily functions with hormones.
Characteristics of Life
- Metabolism: chemical processes (catabolism = breakdown, anabolism = buildup).
- Movement/organization: coordinated actions of body parts.
- Growth: increase in size or cell number.
- Development/differentiation: changes in structure/function over time.
- Responsiveness: sensing and reacting to changes.
- Reproduction: producing new individuals or cells.
Homeostasis
- Maintenance of internal stability (variables kept within setpoint range).
- Controlled by receptors (detect changes), control centers (analyze info), effectors (carry out response).
- Negative feedback reverses changes; positive feedback amplifies changes.
Anatomical Position and Directional Terms
- Anatomical position: standing, facing forward, arms at sides, palms forward.
- Prone: face down; supine: face up.
- Directional terms: superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep, etc.
Body Regions and Quadrants
- Body divided into head, neck, trunk, upper and lower limbs.
- Abdomen divided into four quadrants or nine regions for locating organs.
Body Planes and Sections
- Sagittal plane: divides left/right.
- Frontal (coronal) plane: divides front/back.
- Transverse plane: divides top/bottom.
- Oblique plane: angled cut.
Body Cavities and Serous Membranes
- Major cavities: thoracic (with mediastinum), abdominal, pelvic.
- Serous membranes: parietal (lines cavity), visceral (covers organ), filled with serous fluid.
- Pericardial cavity (heart), pleural cavities (lungs), peritoneal cavity (abdominal organs).
- Mesenteries anchor organs; retroperitoneal organs lie behind peritoneum.
Key Terms & Definitions
- Cytology — study of cells.
- Histology — study of tissues.
- Homeostasis — maintenance of stable internal conditions.
- Negative feedback — mechanism that reverses a deviation from setpoint.
- Anatomical position — standard body posture for descriptions.
- Serous membrane — thin tissue lining body cavities and covering organs.
- Mesenteries — folds of peritoneum that support abdominal organs.
- Retroperitoneal — organs behind the peritoneal lining.
Action Items / Next Steps
- Review diagrams of body planes, quadrants, and major body systems.
- Memorize key directional terms and anatomical regions.
- Read Seeley's Essentials of Anatomy and Physiology, Chapter 1.