Overview
This lecture introduces the fields of anatomy and physiology, their core principles, and the specialized language used to describe the human body.
Introduction to Anatomy & Physiology
- Anatomy is the study of the structure and relationships between body parts.
- Physiology is the study of how body parts function together to keep the body alive.
- Both disciplines explain major life processes such as movement, disease, recovery, and homeostasis.
Historical Background
- Early anatomists performed dissections in secret due to societal taboos.
- Galen studied anatomy using animal vivisections; Leonardo Da Vinci made detailed anatomical drawings.
- Public human dissections became legal and popular in the 17th-18th centuries.
- The Anatomy Act of 1832 in Britain provided legal cadavers for scientific study.
Key Principles
- The complementarity of structure and function means a structure’s form determines what it can do.
- The human body has a hierarchical organization: atoms → cells → tissues → organs → organ systems → organism.
- All living systems maintain homeostasis—stable internal conditions despite external changes.
- Loss of homeostasis leads to death, as seen with organ failure or severe injuries.
Body Organization & Directional Terms
- The body is mapped using standardized anatomical terms.
- Anatomical position: body standing upright, facing forward, arms at sides, palms forward.
- Planes of the body: sagittal (left/right), coronal/frontal (front/back), transverse (top/bottom).
- Axial parts (head, neck, trunk) align with the body’s center; appendicular parts are limbs.
- Key directional terms include anterior (front), posterior (back), superior (above), inferior (below), medial (toward midline), lateral (away from midline), proximal (closer to trunk), distal (further from trunk).
Key Terms & Definitions
- Anatomy — study of the structure and relationships of body parts.
- Physiology — science of how body parts function together.
- Homeostasis — maintenance of stable internal conditions in living organisms.
- Complementarity of structure and function — principle stating that a structure’s ability is based on its form.
- Medial — closer to the body’s midline.
- Lateral — farther from the body’s midline.
- Anterior/Ventral — toward the front of the body.
- Posterior/Dorsal — toward the back of the body.
- Proximal — closer to the point of attachment to the trunk.
- Distal — farther from the point of attachment to the trunk.
Action Items / Next Steps
- Review and memorize anatomical directional terms.
- Study basic cell, tissue, and organ system structures.
- Reference Crash Course Chemistry for atomic-level concepts as needed.