Physiology 1021 Study Guide - Final Guide: Colloid, Pneumothorax, Anterior Pituitary
13 Apr 2012
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Document Summary
Physiology: the study of function in living organisms, exploring the mechanisms by which the organisms control their internal environments, and attempts to explain the physical and chemical factors responsible for both normal function and pathology. External environment: continuous with the outside world: air coming into the lungs has crossed no cellular membrane to get in, contents of g. i. tract is part of external until it has been absorbed. Internal environment: things must cross cells (absorbed, diffused: trillions of cells, each its own entity. Homeostasis: the maintenance of relatively stable conditions in the internal environment. Homeostatic mechanisms are dynamic, self-regulatory mechanisms involving all of the organs and tissues of the body. Uses two control systems (both use negative feedback): endocrine system: slow, long-acting, nervous system: fast, short period. Negative feedback control systems: operate to maintain homeostasis. Measures a value and compares to set point value. If above or below, initiates a series of responses to get back to set point.
