Overview
This lecture introduces the basic concepts of anatomy and physiology, including structural organization, body systems, characteristics of life, homeostasis, and anatomical terminology.
Introduction to Anatomy and Physiology
- Anatomy studies body structures and their relationships; physiology investigates body functions and processes.
- Developmental anatomy examines structural changes from conception to adulthood; embryology focuses on the first 8 weeks.
- Microscopic anatomy includes cytology (cells) and histology (tissues).
- Gross anatomy studies structures visible without a microscope, by systems or regions.
- Surface anatomy involves external observation; anatomical imaging uses technology to view internal structures.
- Pathology studies diseases, their causes, and effects.
Subspecialties of Physiology
- Neurophysiology studies nerve cell functions.
- Endocrinology investigates hormones.
- Cardiovascular physiology covers heart and vessels.
- Immunology studies defense against diseases.
- Respiratory, renal, and pathophysiology explore lungs, kidneys, and disease changes.
Levels of Structural Organization
- Six levels: chemical, cell, tissue, organ, organ system, and organism.
- Chemical: atoms and molecules; cellular: cells and organelles; tissue: groups of similar cells; organ: tissues combined; system: related organs; organism: entire living being.
Organ Systems (Mnemonic: SMILE N CURRD)
- Skeletal, muscular, integumentary, lymphatic, nervous, cardiovascular, urinary, respiratory, reproductive, and digestive systems—each with distinct functions and components.
Characteristics of Life
- Organization, metabolism (chemical reactions), responsiveness, growth, development (differentiation and morphogenesis), and reproduction define living organisms.
Homeostasis and Body Fluids
- Homeostasis is maintaining a constant internal environment.
- Intracellular fluid (inside cells) and extracellular fluid (interstitial, plasma, lymph, CSF, synovial, eye fluids).
Feedback Systems
- Feedback loops monitor and adjust body conditions: receptors detect changes, control centers process, and effectors respond.
- Negative feedback reverses changes (e.g., body temperature); positive feedback amplifies (e.g., childbirth).
Pathophysiology and Disease
- Pathophysiology studies how disease disrupts normal processes due to genetics, environment, or lifestyle.
Anatomical Planes and Directions
- Sagittal divides left/right; transverse divides top/bottom; frontal divides front/back; oblique is at an angle; median is midline.
- Abdomen can be divided into 4 quadrants or 9 regions.
Body Sections, Regions, Cavities
- Longitudinal, transverse, and oblique sections describe organ cuts.
- Main regions: head, neck, trunk; limbs: upper and lower.
- Body cavities: dorsal (cranial and vertebral), ventral (thoracic, abdominopelvic), housing major organs.
Serous Membranes and Cavities
- Serous membranes line cavities and cover organs with parietal (wall) and visceral (organ) layers; fluid between reduces friction.
- Pericardium (heart), pleura (lungs), peritoneum (abdominal organs); mesentery supports digestive organs.
Key Terms & Definitions
- Anatomy — Study of body structures.
- Physiology — Study of body functions.
- Homeostasis — Maintenance of stable internal conditions.
- Negative feedback — Mechanism that reverses a change.
- Positive feedback — Mechanism that amplifies a change.
- Serous membrane — Double-layered lining of body cavities.
- Organ system — Group of organs with a common function.
Action Items / Next Steps
- Review organ system functions using the SMILE N CURRD mnemonic.
- Study anatomical planes and regions for diagram labeling.
- Prepare for reading on tissue types and homeostatic mechanisms.