Anatomy and Physiology Basics

Overview

This lecture introduces the disciplines of anatomy and physiology, explaining their importance, central principles, and basic anatomical terminology used to describe the human body.

Introduction to Anatomy and 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 keep the body alive.
• Together, anatomy and physiology explain both the structure and functions of living organisms.

Interesting Facts About the Human Body

• Human intestines, if stretched out, are as long as a three-story building is tall.
• By old age, a person produces enough saliva to fill multiple swimming pools.
• Humans shed about two-thirds of a kilogram of skin annually, totaling over 50 kilograms in a lifetime.

History of Anatomy

• Early anatomical studies were limited due to social taboos against human dissection.
• Greek physician Galen studied anatomy through animal dissection; later, da Vinci made detailed sketches from human and animal bodies.
• Legalized human dissection in Europe began in the 17th-18th centuries; Britain’s Anatomy Act of 1832 regulated cadaver supply.

Core Principles in Anatomy and Physiology

• Function always reflects structure: what a body part does depends on its form ("complementarity of structure and function").
• The body is organized into levels: atoms → molecules → cells → tissues → organs → organ systems → organism.
• Homeostasis is the maintenance of stable internal conditions necessary for survival; loss of homeostasis results in death.

Anatomical Terminology and Directional Terms

• Anatomical position: body upright, facing forward, arms at sides, palms forward.
• Planes of the body: sagittal (left/right), coronal/frontal (front/back), transverse/horizontal (top/bottom).
• Axial parts: head, neck, trunk; Appendicular parts: limbs (arms and legs).
• Anterior (ventral) = front; Posterior (dorsal) = back.
• Superior (cranial) = above; Inferior (caudal) = below.
• Medial = toward the midline; Lateral = away from the midline.
• Proximal = closer to trunk; Distal = farther from trunk.

Key Terms & Definitions

• Anatomy — Study of the structure and relationships of body parts.
• Physiology — Science of body part functions and interactions.
• Homeostasis — Maintenance of stable internal body conditions.
• Complementarity of structure and function — Structure determines function.
• Anatomical position — Standard reference stance for anatomical terminology.
• Sagittal plane — Divides body into left and right.
• Coronal (frontal) plane — Divides body into front and back.
• Transverse plane — Divides body into upper and lower parts.

Action Items / Next Steps

• Review and memorize key anatomical directional terms and planes.
• Prepare for upcoming lessons on body systems and their specific functions.