chapter 9: homeostasis

Question 1

homeostasis

Answer 1

a relatively stable, balanced internal environment that is optimized for cellular activities

Question 2

motivation

Answer 2

psychological process that induces or sustains a particular behavior

Question 3

endotherms

Answer 3

we make our own heat inside our bodies using metabolism and muscular activity

Question 4

ectotherms

Answer 4

animals that get their heat from outside the body

Question 5

negative feedback

Answer 5

process whereby a system monitors its own output and reduces its activity when a setpoint is reached

Question 6

set point

Answer 6

a point of reference in a feedback system

Question 7

allostasis

Answer 7

varying behavioral and physiological adjustments that an individual makes in order to maintain optimal functioning of a regulated system in the face of changing environmental stressors

Question 8

obligatory losses

Answer 8

unavoidable expenditures of bodily resources that must then be regained from the external environment

Question 9

intracellular compartments

Answer 9

water that is contained within our cells

Question 10

extracellular compartments

Answer 10

fluid that is outside of our cells, divided between interstitial fluid and blood plasma

Question 11

diffusion

Answer 11

molecules of a substance (solute) dissolved in another substance (solvent) with move until a uniform concentration is achieved

Question 12

osmosis

Answer 12

passive movement of a solvent, usually water, through a semipermeable membrane until a uniform concentration of solute (often salt) is achieved on both sides of the membrane

Question 13

osmotic pressure

Answer 13

physical force that pushes or pulls water across the membrane

Question 14

osmotic thirst

Answer 14

a desire to ingest fluids that is stimulated by high concentration of solute (salt) in the extracellular compartment

Question 15

osmosensory neurons

Answer 15

neurons that specifically monitor the concentration of the extracellular fluid

Question 16

circumventricular organs

Answer 16

monitor the concentration of extracellular fluid

Question 17

vasopressin

Answer 17

pituitary hormone which acts on the kidneys to slow the production of urine by increasing the reabsorption of water

Question 18

aldosterone

Answer 18

a mineral cortical hormone, secreted by the adrenal cortex, that promotes the conservation of sodium by the kidneys

Question 19

hypovolemic thirst

Answer 19

the concentration of the fluid has not changed, salt and ions are also lost

Question 20

baroreceptors

Answer 20

a pressure receptor in the heart or a major artery that detects a change in blood pressure

Question 21

angiotensin ll (All)

Answer 21

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

Question 22

vagus nerve

Answer 22

transmits signals from the viscera to the brain about saltiness of fluid in the gut

Question 23

nutrients

Answer 23

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

Question 24

glucose

Answer 24

sugar molecule used by the body and brain for energy

Question 25

glycogen

Answer 25

complex carbohydrates made by combining glucose molecules for short term store of energy

Question 26

insulin

Answer 26

pancreatic hormone that lowers blood glucose, promotes energy storage, and facilitates glucose utilization by cells

Question 27

glucagon

Answer 27

converts glycogen back into glucose

Question 28

lipid

Answer 28

large molecule (usually fay) that consists of fatty acids and glycerol

Question 29

basal metabolism

Answer 29

energy used for heat production, maintenance of membrane potentials, and life sustaining processes

Question 30

diabetes mellitus

Answer 30

excessive glucose in the blood and urine and by reduced glucose utilization by body cells that is caused by the failure of insulin to induce glucose absorption

Question 31

ventromedial hypothalamus

Answer 31

hypothalamic region involved in sexual behaviors, eating, and aggression

Question 32

lateral hypothalamus

Answer 32

hypothalamic region involved in the control of appetite and other functions

Question 33

arcuate nucleus

Answer 33

hypothalamic nucleus implicated in appetite control by integrating peptide hormone signals from several sites in the body

Question 34

leptid

Answer 34

peptide hormone released by fat cells

Question 35

ghrelin

Answer 35

synthesized and released by endocrine cells of the stomach, reaches high levels before eating, drops off after eating, works as an appetite stimulant

Question 36

PYY3-36

Answer 36

released by intestinal cells, reaches high levels after eating, works as an appetite suppressant

Question 37

glucagon-like peptide 1 (GLP 1)

Answer 37

increased during a meal, suppresses appetite, blocks effects of ghrelin

Question 38

POMC neurons

Answer 38

act as satiety neurons when activated, inhibiting appetite and increasing metabolism

Question 39

NPY neurons

Answer 39

act as hunger neurons when activated, stimulating appetite directly and also inhibiting the POMC neurons and reducing metabolism

Question 40

cholecystokinin (CCK)

Answer 40

peptide hormone that is released from the gut after ingestion of food that is high in protein and/or fat

Question 41

orexin

Answer 41

neurons of the hypothalamic appetite system that promote feeding bahavior

Question 42

endocannabinoid

Answer 42

an endogenous ligand of cannabinoid receptors, thus an analog of cannabis that is produced by the brain

Question 43

enterotype

Answer 43

each individuals personal combination of gut microbiota

Question 44

hormones

Answer 44

are molecules released by a cell into the bloodstream, where they can travel throughout the body to target tissues and bind to their receptors in the tissue, causing some sort of effect