Anatomy and Physiology Overview

Anatomy and Physiology

• Anatomy studies the form and structure of the body.
• Physiology examines how the body functions.
• Form and function are interrelated—anatomical structures are designed for a specific function.
• Integrating anatomy and physiology is the easiest way to learn about both.

Levels of Structural Organization

• Chemical: Atoms, molecules, macromolecules (e.g., hydrogen, water, carbohydrates).
• Cellular: Cells, the basic units of life (e.g., erythrocytes (red blood cells), epithelial cells (skin cells)).
• Tissue: Tissues, similar cells performing common functions (e.g., connective, muscle, epithelial, and nervous tissue).
• Organ: Organs, multiple tissues working together (e.g., heart, lungs, brain).
• Organ system: Related organs working together (e.g., cardiovascular, respiratory, nervous).
• Organismal: Organ systems functioning together.

History of Anatomy

• Ancient Egypt: Edwin Smith Papyrus (~1600 BC) described the brain, meninges, CSF, and heart, and injury treatments.
• Ancient Greece: Hippocrates ("Father of Medicine") laid the foundation for modern spine surgery. Aristotle noted structural aspects but had inaccuracies in physiological concepts (e.g., believed intelligence was in the heart).
• Middle Ages: Claudius Galen's teachings formed the basis of medical education, though his work relied mainly on animal dissections.
• Renaissance: Leonardo da Vinci dissected animals and humans and sketched his findings. Andreas Vesalius, the "Father of Modern Anatomy," emphasized dissection-based learning.
• Modern Day: Dr. Frank Netter produced over 4,000 illustrations, crucial reference material for medical students.

Overview of Organ Systems

• Integumentary System: Protects deeper tissue, regulates temperature, synthesizes vitamin D, contains sensory receptors.
• Skeletal System: Protects organs, framework for movement, stores minerals, site of blood cell formation (hematopoiesis).
• Muscular System: Function is contraction. Allows movement, manipulation, facial expression, and maintains posture (skeletal, smooth, and cardiac muscle types).
• Nervous System: Fast-acting control system. Contains brain, spinal cord, nerves, sensory receptors; receives and sends signals.
• Endocrine System: Glands secrete hormones that regulate growth, reproduction, and nutrient use.
• Cardiovascular System: Contains heart and blood vessels. Pumps blood transporting oxygen, carbon dioxide, nutrients, hormones, and wastes.
• Lymphatic System: Returns leaked fluid to blood vessels, cleanses blood, stores white blood cells (involved in immunity).
• Respiratory System: Supplies oxygen, removes carbon dioxide. Includes nasal passages, pharynx, larynx, trachea, bronchi, and lungs; gases are exchanged in air sacs.
• Urinary System: Removes waste, maintains water and acid-base balance.
• Digestive System: Tube from mouth to anus. Breaks down food to absorbable units entering the bloodstream; undigested food is excreted.
• Reproductive System: Produces offspring.