ANATOMY Study of the structure and shape of the body and its parts PHYSIOLOGY Study of how the body and its parts work or function How the body functions both on a microscopic and macroscopic level Levels of Organization cell smallest living unit Tissues Collection of cells of same type Organs Collection of two or more types of tissues put together into structures that perform a specific function Organ systems Collection of organs that work together to accomplish a particular task Some Survival Needs Nutrients Chemicals for energy and cell building Includes carbohydrates proteins lipids vitamins and minerals Oxygen required for chemical reactions WATER 60 80 of body weight Needed for many for metabolic reactions Homeostasis steady state Stable body temperature Maintain blood plasma pH Maintain blood pressure Maintain water balance Stable blood sugar levels Primary Cells Tissue Classes Over 200 types of cells divided into 4 general categories 1 Muscle contraction generation of force 2 Connective connect anchor support 3 Epithelial barrier between body and external environment exchange 4 Nerve initiate transmit electrical impulses Body Fluid Compartments For a 70 kg man total body water 42 liters 28 liters intracellular fluid ICF 14 liters extracellular fluid ECF 3 liters plasma 11 liters interstitial fluid ISF Immune and Lymphatic System Returns fluids to blood vessels Cleanses the blood Protects the body from pathogens HOUSE KEEPING Cardiovascular System Transports materials in body via blood pumped by heart Oxygen Carbon dioxide NUTRIENTS Wastes Respiratory System Keeps blood supplied with oxygen Removes CARBON DIOXIDE Maintains blood plasma pH Urinary System Eliminates WASTES Maintains acid base balance Regulates water and electrolytes Reproductive System Produces offspring Not required for HOMEOSTASIS Digestive System Breaks down food Allows for nutrient absorption into BLOOD Eliminates indigestible material Interrelationships Among Body Systems Homeostasis Is A Central Organizing Principle of Physiology Is the process of maintaining stable internal environment compatible for life Most organ systems contribute to homeostasis Exception REPRODUCTIVE SYSTEM Negative Feedback Control in Homeostasis Homeostasis in Action Thermoregulation and Negative Feedback Homeostasis Homeostasis is used for the maintenance of a stable internal environment A dynamic state of equilibrium STEADY STATE Homeostasis is necessary for normal body functioning and to sustain life Homeostatic imbalance A disturbance in homeostasis resulting in disease Negative Feedback Control is used to maintain Homeostasis Most organ systems contribute to homeostasis the exception is the if not corrected reproductive system Maintaining Homeostasis Through Neural and Hormonal Control Systems Receptor sensors Responds to changes in the environment stimuli detect level of regulated variable and provide input to INTEGRATING Sends information to control center CENTER Control center Integrating center Determines set point usually in the brain desired level of regulated variable and analyzes information usually in the brain compares set point to actual level of regulated variable and sends output to effectors to return regulated variable toward set point Determines appropriate response Effector provides a means for response to the stimulus Negative Feedback Control in Homeostasis Primary mechanism for maintaining homeostasis Body s response the original stimulus is to offset it so that it is within normal physiological set points External change triggers change in a regulated variable in internal environment this triggers a reaction to oppose the detected change and return regulated variable toward normal parameters SET POINT Thermoneutral Zone and Normal Body Temperature is 37 C Thermoneutral zone if the range of outside temperature where alterations in blood flow alone regulates body temperature 25 30oC Body temperature increase blood flow to skin INCREASES Body temperature decrease blood flow to skin decreases Negative Feedback Mechanisms Negative feedback includes most HOMEOSTATIC control mechanisms Shuts off the original stimulus or reduces its intensity Works like a thermostat Positive Feedback Loop POSITIVE feedback loops cause a rapid change in a variable Not a common mechanism for maintaining homeostasis Response increases the original stimulus as opposed to canceling it out Stimulus must end for response to end Labor child birth milk let down blood clotting Increases the original stimulus to push the variable farther A Summary of Feedback Loops
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