1 List the three components of a homeostatic response mechanism and briefly describe what the function of each is. How does negative feedback control work to terminate a homeostatic response? Receptor – measures the internal environment for some parameter and reports value to integrator Integrator – evaluates info from receptor and decides whether or not to something needs to be done. If it does, initiates the action of the effector Effector – actually does something to modify the internal environment In negative feedback control, the action of the effector will eventually cause the cessation of the homeostatic response 2 With respect to the human body, distinguish between the external environment, the internal environment, and the cellular environment the external environment is the atmosphere in which the organisms lives, the internal environment consists of the interstitial fluid that bathes the cells and the plasma of the blood. The cellular environment consists of everything inside the cell membranes of all the cells of the body. 3 List the four chambers of the human heart and for each state 1) where blood entering that chamber has come from and 2) where blood exiting is going. What prevents blood from flowing back in the wrong direction? Rt atrium – thinly muscled, blood enters it from systemic loop, blood exits it into the rt ventricle Rt ventricle – thickly muscled, blood enters it from rt atrium, blood exits it to pulmonary loop Lft atrium – thinly muscled, blood enters it from pulmonary loop, blood exits it into lft ventricle. Lft ventricle – thickly muscled, blood enters it from lft atrium, blood exits it into systemic loop. One way flow valves prevent backflow of blood into all these chambers ng is going. What prevents blood from flowing back in the wrong direction?

4 Briefly describe the basic structure of an artery, vein, and capillary Artery: large