Overview
This lecture introduces core concepts in anatomy and physiology, covering historical context, organization levels, organ systems, and essential terminology for understanding the human body.
Historical Background
- Early anatomy relied on superstition, observation, and basic healing practices.
- Advancements included experimentation, new terminology, and cadaver dissection.
Branches of Anatomy
- Gross anatomy studies large structures (regional, systemic, surface).
- Microscopic anatomy focuses on cells (cytology) and tissues (histology).
- Developmental anatomy examines embryo changes before birth.
- Pathology investigates structural changes from disease.
Form and Function Principle
- Structure (anatomy) always relates to function (physiology).
- Physiology describes chemical and physical processes in living systems.
Levels of Organization
- Chemical: atoms and molecules.
- Cellular: basic living units.
- Tissue: groups of similar cells.
- Organ: combinations of tissues.
- Organ system: organs working together.
- Organism: integrated organ systems.
Organ Systems (A&P 1 Focus)
- Integumentary: protects, regulates temperature, produces vitamin D.
- Skeletal: supports, moves body, makes blood cells, stores minerals.
- Muscular: enables movement, maintains posture, produces heat.
- Nervous: controls quickly, sends signals, processes intellect.
Microbiome
- The human body contains trillions of microbes, varying by age, location, and lifestyle.
- Beneficial bacteria are essential for health; there is no single ideal microbiome.
Characteristics of Life
- Organization: separation and coordination of internal/external parts.
- Metabolism: chemical reactions including anabolism (builds/stores) and catabolism (breaks down/releases).
- Responsiveness: ability to react to changes.
- Growth: increase in size or cell number.
- Development: differentiation and life changes.
- Reproduction: making new organisms.
Survival Needs
- Requires nutrients, water (~70% of body), oxygen, proper atmospheric pressure, and homeostasis.
Homeostatic Control
- Three components: receptor, control center, effector.
- Negative feedback reduces change (e.g., temperature regulation).
- Positive feedback increases change until a specific endpoint (e.g., childbirth).
Anatomical Position & Directional Terms
- Reference: standing, feet apart, palms forward, thumbs out.
- Terms: anterior/posterior, superior/inferior, medial/lateral, proximal/distal, superficial/deep.
Body Planes
- Sagittal: divides left/right.
- Frontal (coronal): divides anterior/posterior.
- Transverse: divides superior/inferior.
Body Cavities & Serous Membranes
- Dorsal cavity: cranial and spinal.
- Ventral cavity: thoracic (pleural, pericardial), abdominopelvic (abdominal, pelvic).
- Serosa: parietal (lines cavity) vs visceral (covers organ); reduces friction.
- Pleura (lungs), pericardium (heart), peritoneum (abdominal organs).
Abdomen Mapping
- Four quadrants and nine regions help localize clinical findings.
Regional Terms (Selected)
- Head: frontal, orbital, nasal, oral, otic.
- Trunk: cervical, thoracic, pectoral, abdominal, pelvic, lumbar.
- Upper limb: brachial, antebrachial, carpal, palmar, digital.
- Lower limb: femoral, crural, tarsal, plantar, hallux.
Key Terms & Definitions
- Anatomy — study of body structure.
- Physiology — study of body function.
- Homeostasis — maintaining stable internal conditions.
- Negative Feedback — mechanism counteracting changes.
- Positive Feedback — mechanism amplifying changes to a set point.
- Serosa — slippery membrane lining cavities and organs.
- Anabolism — metabolic process building molecules, storing energy.
- Catabolism — metabolic process breaking down molecules, releasing energy.
- ATP — cell’s immediate energy currency.
Action Items / Next Steps
- Review and memorize directional, regional, and body plane terms.
- Study organ system functions and relationships.
- Practice identifying abdominal quadrants and regions.