Overview
This lecture introduces the foundations of anatomy and physiology, the organization of the human body, key scientific principles, and essential anatomical terminology.
What Is Anatomy & Physiology?
- Anatomy is the study of the structure and relationships between body parts.
- Physiology is the science of how body parts function and work together to sustain life.
- Anatomy focuses on "what" the body is; physiology focuses on "what it does."
- These disciplines explain processes like movement, disease, healing, and vital functions.
Central Principles
- The complementarity of structure and function: what a body part can do depends on its shape and form.
- The study of human anatomy has a long history, including taboo periods and use of educational cadavers.
- Knowledge about body functions comes from studying both living systems and deceased bodies.
Levels of Organization
- The body is organized hierarchically: atoms → molecules → cells → tissues → organs → organ systems → organism.
- Cells are the smallest living units and vary in size and shape for specialized functions.
- Tissues are groups of similar cells; organs are combinations of tissues with specific jobs.
- Organ systems are groups of organs working together for overall body function.
- The complete organism is the highest level, made up of trillions of cells.
Homeostasis
- Homeostasis is the process by which living systems maintain stable internal conditions despite external changes.
- Survival depends on keeping balances in blood, water, nutrients, oxygen, temperature, and waste removal.
- Loss of homeostasis causes organ failure and ultimately death.
Anatomical Position & Directional Terms
- Standard anatomical position: body upright, facing forward, arms at sides, palms forward.
- Body planes:
- Sagittal: divides left and right.
- Coronal (frontal): divides front and back.
- Transverse (horizontal): divides top and bottom.
- Axial parts are the head, neck, and trunk; appendicular parts are arms and legs.
- Directional terms:
- Anterior/ventral: front; posterior/dorsal: back.
- Superior (cranial): above; inferior (caudal): below.
- Medial: toward the midline; lateral: away from midline.
- Proximal: closer to trunk; distal: farther from trunk.
Key Terms & Definitions
- Anatomy — study of body structure and relationships between parts.
- Physiology — study of functions and processes of body parts.
- Homeostasis — maintenance of stable internal conditions.
- Complementarity of structure and function — principle that structure determines function.
- Tissue — group of similar cells with specific function.
- Organ — a structure with two or more tissue types working together.
- Organ system — group of organs performing related functions.
- Anatomical position — standard body posture for reference.
- Sagittal, coronal, transverse planes — imaginary lines dividing the body for study.
Action Items / Next Steps
- Review and memorize key anatomical directional terms and body planes.
- Prepare for understanding more detailed structures and functions in future lessons.