Biol1140_57 Anatomy and Physiology Martini_Nath - CH01

path59's version from 2015-09-28 19:16


Question Answer
anatomythe study of the STRUCTURE of the body, including internal and external structures
physiologythe study of the FUNCTION of those structures
The levels of organization of organisms (from simplest to the most complex)  Molecules  Cells  Tissues  Organs  Organ systems  Organism
Define homeostasisrefers to the existence of a stable internal enviroment ( all body systems are working together to maintain a stable internal environment)
(homeostasis) Define intrinsic regulation (autoregulation)occurs when a cell, a tissue, an organ, or an organ system adjusts its activities automatically in reponse to some environmental change (ex when oxygen levels decline in a tissue --> the cells release chemical that cause blood vessel dilation ---> dilation incr rate of O flow and provides more O to region
(homeostasis) Extrinsic regulation a response controlled by nervous and endocrine systems (The nervous system directs rapid, short-term, very specific responses (hot stove!) The endocrine system directs slower, longer-term, broad responses involving hormones (development, pregnancy))
state of equilibriumOrgan systems work together, adapting and adjusting, to achieve this
positive feedbackwhich enhances a variation from “normal” after an initial stimulus, to achieve a particular effect--The response of the effector increases change of the stimulus •Body is moved further away from homeostasis and further out of normal range •Produces extreme, fast responses in dangerous or stressful situations • Less common •Shorter term
Example of positive feedbackblood vessel breaks -> damaged cells release chemicals -> clotting begins -> (positive feedback loop)1) additional chemical releases <-> 2) clotting accelerates -> leads to Blood clot plugs breaks in vessel walls and bleeding stops
negative feedback•The response of the effector negates the stimulus •Body is brought back to a normal range •Most common •Longer term
Example of negative feedback•Stimulus: body temperature rises •Receptors - Temperature sensors in skin and hypothalamus detect and send info to thermoregulatory control center (brain) which sends command to • Effectors - Sweat glands in skin increase secretion/ blood vessels in skin dilate • Response: Increased heat loss, body temp drops • Return to homeostasis