Exam 3 (Chapters 9, 10, 12, 13, and 14)

• homeostasis


  the maintenance of a relatively constant internal physiological environment
• motivation


  the psychological process that induces or sustains a particular behavior
• thermoregulation


  the active process of maintaining a relatively constant internal temperature through behavioral and physiological adjustments
• endotherm


  an animal whose body temperature is regulated chiefly by metabolic processes
• ectotherm


  an animal whose body temperature is regulated by the environment
• negative feedback


  the process whereby a system monitors its own output and reduces its activity when a set point is reached
• set point


  the point of reference in a feedback system
• set zone


  the optimal range of a variable that a negative feedback system tries to maintain
• allostasis


  the varying behavioral and physiological adjustments that an individual makes in order to maintain optimal (rather than unchanging) functioning of a regulated system in the face of changing environmental stressors
• intracellular compartment


  the fluid of the body that is contained within cells
• extracellular compartment


  the fluid of the body that exists outside the cells
• osmosis


  the passive movement of a solvent, usually water, through a semipermeable membrane until a uniform concentration of a solute is achieved on both sides of the membrane
• diffusion


  the passive spread of solute molecules through a solvent until a uniform solute concentration is achieved
• osmotic pressure


  the tendency of a solvent to move across a membrane in order to equalize the concentration of solute on both sides of the membrane
• osmotic thirst


  a desire to ingest fluids that is stimulated by high concentration of solute in the extracellular compartment
• osmosensory neuron


  a specialized neuron that monitors the concentration of the extracellular fluid by measuring the movement of water into and out of the intracellular compartment
• circumventricular organ


  any of multiple distinct sites that lie in the wall of a cerebral ventricle and monitor the composition of cerebrospinal fluid
• vasopressin


  a peptide hormone from the posterior pituitary that promotes water conservation and increases in blood pressure
• aldosterone


  a mineralcorticoid hormone, secreted by the adrenal cortex, that promotes the conservation of sodium by the kidneys
• hypovolemic thirst


  a desire to ingest fluids that is stimulated by a reduction in volume of the extracellular fluid
• baroreceptor


  a pressure receptor in the heart or a major artery that detects a change in blood pressure
• atrial natriuretic peptide


  a hormone, secreted by the heart, that normally reduces blood pressure, inhibits drinking, and promotes the excretion of water and salt at the kidneys
• angiotensin


  a hormone produced in the blood by the action of renin that may play a role in the control of thirst
• vagus nerve


  cranial nerve X, which transmits information between the brain and the viscera
• nutrients


  chemicals required for the effective functioning, growth, and maintenance of the body
• glucose


  an important sugar molecule used by the body and brain for energy
• glycogen


  a complex carbohydrate made by the combining of glucose molecules for a short-term store of energy
• glucagon


  a pancreatic hormone that converts glycogen to glucose and thus increases blood glucose
• lipid


  a large molecule that consists of fatty acids and glycerol
• adipose tissue


  tissue made up of fat cells
• ketone


  an organic molecule derived from the breakdown of fat that can be used by cells as an energy source
• basal metabolism


  the use of energy for processes such as heat production, maintenance of membrane potentials, and all the other basic life-sustaining functions of the body
• diabetes mellitus


  a condition, characterized by excessive glucose in the blood and urine and reduced glucose utilization by body cells that is caused by the failure on insulin to induce glucose absorption
• glucodetector


  a specialized type of liver cell that detects and informs the nervous system about levels of circulating glucose
• ventromedial hypothalamus


  a hypothalamic region involved in eating and sexual behaviors
• lateral hypothalamus


  a hypothalamic region involved in the control of appetite and other functions
• arcuate nucleus


  an arc-shaped hypothalamic nucleus implicated in appetite control
• ghrelin


  a peptide gut hormone believed to act on the hypothalamic appetite system to increase hunger
• PYY3-36


  a peptide gut hormone believed to act on the hypothalamic appetite system to suppress appetite
• glucagon-like peptide 1


  a peptide gut hormone believed to act on the hypothalamic appetite system to suppress appetite