Lecture 1, Part 1: Introduction to Anatomy & Physiology Anatomy – Greek for “a cutting open” Study of internal and external structures of the body and the physical relationships among body parts Physiology – Study of how living organisms perform their vital functions

Anatomy & Physiology Physiology – Anatomy – Chemical knowledge: Gross Anatomy (macroscopic anatomy) – Microscopic Anatomy – Cytology – internal structure of cells Histology – tissues Physiology – Chemical knowledge: Acids/Bases Cations/Anions ATP

Levels of Structural Organization Chemical Level (Atoms and Molecules) Cellular Tissue Organ Organ System Organism SIMPLEST MOST COMPLEX See pg. 7!!!

Levels of Structural Organization

Homeostasis Existence of a stable internal environment All living organisms MUST maintain homeostasis Failure to maintain homeostasis = illness or death Autoregulation (intrinsic regulation) – cell, tissue, organ, organ system adjusts activities automatically Happens “all the time” Extrinsic regulation – results from activities of nervous or endocrine systems Happens “when needed” triggered by outside influence

Homeostatic Control Mechanisms Receptor – sensor sensitive to particular environmental change Control center – receives and processes information supplied by receptor Effector – cell or organ that responds to commands of control center See pg. 11 Control Center Effector Receptor Can you name the Receptor, Control Center and Effector in this simple thermostat diagram?

Feedback Loops Negative Feedback Loop Most homeostatic mechanisms Example: Control of body temperature – thermoregulation Control center: brain Receptors: skin Effectors: muscle tissue in walls of blood vessels supplying skin and sweat glands See pg. 12

Feedback Loops Positive Feedback Loop Initial stimulus produces response that exaggerates or enhances change in conditions Produces extreme responses Found when potentially dangerous/stressful process must be completed quickly Example: Blood clotting See pg. 14

THE END