AP 151 Introduction to Human Physiology

1. 1-1 AP 151Introduction to Human Physiology Chapter 1 HOMEOSTASIS

2. 1-2 Physiology Considers the operation of specific organ systems Renal � kidney function Neurophysiology � workings of the nervous system Cardiovascular � operation of the heart and blood vessels Focuses on the functions of the body, often at the cellular or molecular level Understanding physiology also requires a knowledge of physics, which explains electrical currents, blood pressure, and the way air pressure allows the movement of air into and out of the lungs

3. 1-3 Approaches to Physiology Mechanistic approach - asks �how� a function occurs How do red blood cells carry oxygen? Teleological approach - asks �why� a function occurs Why do red blood cells carry oxygen?

4. 1-4 Body Environments and Fluids External environment The air in which we live Body fluids - two major compartments Intracellular fluid - cytosol; fluid within cells (28 L=67%) Extracellular fluid - all fluid outside cells of the body Plasma - liquid component of blood (3L=7%) Interstitial fluid - aka, tissue fluid; fluid bathing cells (11L=26%) Claude Bernard called this the �milieu interieux�; the internal environment. There is a constant interaction between these 3 fluids They are separated form one another only by cell membranes Therefore, changing one (especially tissue fluid) has effects on the other two

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