Overview
This lecture introduces human anatomy and physiology, explaining their importance, history, main principles, organizational hierarchy, and essential anatomical terminology.
Introduction to Anatomy and Physiology
- Anatomy studies the structure and relationships between body parts.
- Physiology explores how body parts function together to sustain life.
- The disciplines are connected and explain fundamental life processes like movement, eating, and thinking.
Historical Context
- Early anatomical studies were limited by taboos about dissection.
- Key figures included Galen and Da Vinci, who advanced anatomical knowledge through animal and human studies.
- Legal dissection of human bodies began in the 17th and 18th centuries, leading to public dissections.
- Today, cadaver study is legal and based on voluntary body donation.
Core Principles
- The function of any body part reflects its structure; this is the complementarity of structure and function.
- All living things are made of atoms, organized into cells, tissues, organs, organ systems, and ultimately the whole organism.
- Homeostasis is the body's ability to maintain stable internal conditions despite external changes.
- Loss of homeostasis leads to death (e.g., organ failure, hypothermia, severe bleeding).
Levels of Organization
- Atoms combine to form molecules, which create cells (basic units of life).
- Cells group to form tissues (muscle, nervous, connective, etc.).
- Tissues combine to create organs (heart, liver, lungs).
- Organs function together as organ systems (digestive, circulatory, etc.).
- All systems make up the complete organism.
Anatomical Position and Directional Terms
- Anatomical position: body standing upright, facing forward, arms at sides, palms facing forward.
- Planes: sagittal (left/right), coronal/frontal (front/back), transverse/horizontal (top/bottom).
- Axial parts: head, neck, trunk; appendicular parts: arms, legs.
- Directional terms: anterior/ventral (front), posterior/dorsal (back), superior/cranial (above), inferior/caudal (below), medial (toward midline), lateral (away from midline), proximal (closer to trunk), distal (farther from trunk).
Key Terms & Definitions
- Anatomy — the study of body structure and relationships between parts.
- Physiology — the study of how body parts work together to function.
- Homeostasis — the maintenance of stable internal conditions by living organisms.
- Complementarity of structure and function — structure determines function at every body level.
- Anatomical position — standard body orientation for describing locations and directions.
- Sagittal plane — divides body into left and right parts.
- Coronal (frontal) plane — divides body into front and back parts.
- Transverse (horizontal) plane — divides body into top and bottom parts.
- Medial — toward the midline of the body.
- Lateral — away from the midline of the body.
- Proximal — closer to the trunk or origin.
- Distal — farther from the trunk or origin.
- Anterior/ventral — toward the front.
- Posterior/dorsal — toward the back.
Action Items / Next Steps
- Review anatomical directional terms and planes.
- Reflect on the main principles: complementarity of structure/function and homeostasis.
- Prepare for upcoming lessons by revisiting Crash Course Chemistry as needed.