Overview
This lecture introduces human anatomy and physiology, emphasizing definitions, organization of the body, organ systems, requirements for survival, and the concept of homeostasis.
Introduction to Anatomy and Physiology
- Anatomy studies the structure of body parts and their relationships.
- Physiology explores the functions of body parts and vital processes.
- Understanding both is essential for explaining symptoms and health conditions.
Subdivisions of Anatomy
- Gross (macroscopic) anatomy examines large, visible structures by region, system, or surface.
- Microscopic anatomy studies structures requiring magnification, including cytology (cells) and histology (tissues).
- Developmental anatomy covers body changes throughout life; embryology focuses on development before birth.
Subdivisions of Physiology
- Physiology can be system-based (e.g., renal, neurophysiology, cardiovascular).
- Cell physiology focuses on function at cellular and molecular levels.
Complementarity of Structure and Function
- Structure and function are closely linked, as shown in examples like teeth and the heart.
Levels of Structural Organization
- Organization levels: chemical (atoms, molecules), cellular, tissue, organ, organ system, and organismal.
- Tissues are groups of similar cells; organs contain multiple tissue types; organ systems consist of related organs.
Characteristics Necessary for Life
- Key life functions: maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, and growth.
- Homeostasis involves all organ systems working together to maintain life.
Overview of Organ Systems
- Integumentary: skin, hair, nails; protection, vitamin D synthesis, sensory.
- Skeletal: bones, cartilage; support, protection, mineral storage, blood formation.
- Muscular: skeletal muscles; movement, posture, heat production.
- Nervous: brain, spinal cord, nerves; rapid response, coordination, sensation.
- Endocrine: glands; long-term regulation via hormones.
- Cardiovascular: heart, vessels; transport of blood, nutrients, wastes, temperature regulation.
- Lymphatic: spleen, lymph nodes; defense, fluid return.
- Respiratory: lungs, airways; gas exchange, sound production.
- Digestive: GI tract, liver, pancreas; nutrient breakdown, absorption, waste elimination.
- Urinary: kidneys, bladder; waste excretion, water/ion balance.
- Reproductive: testes/ovaries; sex cell/hormone production, nurturing offspring.
Requirements for Survival
- Necessities: nutrients (carbs, proteins, fats, vitamins/minerals), oxygen, water, normal body temperature, adequate atmospheric pressure.
Homeostasis and Control Mechanisms
- Homeostasis is maintaining stable internal conditions despite environmental changes.
- Controlled via nervous (fast) and endocrine (slow, long-lasting) systems.
- Key variables: blood sugar, body temperature, blood volume.
- Components: receptor (senses change), control center (processes info), effector (acts to restore balance).
- Negative feedback reduces changes (e.g., temperature, blood glucose regulation).
- Positive feedback enhances changes (e.g., blood clotting, childbirth).
Homeostatic Imbalance and Disease
- Disease and aging result when homeostatic mechanisms fail or become inefficient (e.g., diabetes, heart failure).
Key Terms & Definitions
- Anatomy — study of body structure and relationships between parts.
- Physiology — study of body part functions and vital processes.
- Cytology — study of individual cells.
- Histology — study of tissues.
- Homeostasis — maintenance of stable internal conditions.
- Negative feedback — corrective mechanism that opposes change.
- Positive feedback — mechanism that amplifies change until a process is completed.
Action Items / Next Steps
- Review Chapter 1, focusing on definitions and organ system overviews.
- Memorize the 11 organ systems and their major functions for next class.