Regulation

Question 1

allostasis

Answer 1

adaptive way the body anticipates needs depending on the situation

Question 2

basal metabolism

Answer 2

energy used to maintain constant body temp at rest

Question 3

poikilothermic

Answer 3

ectothermic
body temp matches that of environment
amphibians, reptiles, fish
organism lacks mech of internal reg

Question 4

homeothermic

Answer 4

endothermic
use of internal mechs to maintain almost constant body temp

mammals and birds
requires energy and fuel

sweating/panting decrease temp
shivering/fluffing fur increase temp

Question 5

preoptic area/anterior hypothalamus

Answer 5

POA/AH
responsible for body temp regulation
receieves input from immune system, skin, and brain

Question 6

vasopressin

Answer 6

hormone released by posterior pituitary 
raises blood pressure 
helps compensated for decreased water volume 
antidiuretic hormone 
kidneys reabsorb water

Question 7

osmotic thirst

Answer 7

results from eating salty foods

Question 8

hypovolemic thirst

Answer 8

results from loss of fluids due to sweating or bleeding

Question 9

osmotic pressure

Answer 9

solutes inside and outside cell create

water travels across semi-permeable membrane from area of low solute to an area of high

occurs when solutes are more concentrated on one side

draws water from the cell

Question 10

OVLT

Answer 10

detects osmotic pressure

relays information to supraoptic nucleus and paraventricular nucleus

Question 11

vagus nerve

Answer 11

Conveys information about the stretching of

the stomach walls to the brain

Question 12

Splanchnic nerves

Answer 12

Convey information about the nutrient

contents of the stomach

Question 13

Duodenum

Answer 13

Part of the small intestine
initial absorption of nutrients
Distention of the duodenum can produce feelings of satiety
releases the hormone cholecystokinin (CCK), which helps to regulate hunger

Question 14

Cholecystokinin (CCK)

Answer 14

released by duodenum

regulates hunger by:
Closing the sphincter muscle between the
stomach and duodenum and causing the
stomach to hold its contents and fill faster

Stimulating the vagus nerve to send a
message to the hypothalamus

Question 15

Glucose

Answer 15

Main product of digestion
Important source of energy for the body
Nearly the only fuel used by the brain 
Excess glucose enters the liver and fat
cells 

BLOOD GLUCOSE LEVES DECLINE, INSULIN INCREASES

Question 16

Insulin

Answer 16

Pancreatic hormone that enables glucose
to enter the cell (except brain)

After a meal:
– Blood glucose levels fall
– Insulin levels drop
– Glucose enters cells more slowly
– Hunger increases
– Pancreas releases glucagon

Question 17

Glucagon

Answer 17

Hormone released by the pancreas when glucose levels fall

Stimulates the liver to convert some of its
stored glycogen to glucose to replenish low supplies in the blood

Question 18

Leptin

Answer 18

peptide
signals the brain to increase or decrease eating

Low levels of leptin increase hunger

High levels reduce eating and increase
physical and immune system activity

Question 19

arcuate nucleus

Answer 19

receives information from all parts of the body
regarding hunger
part of the hypothalamus 
containing two sets of neurons
Neurons sensitive to hunger signals
Neurons sensitive to satiety signals

Question 20

Ghrelin

Answer 20

Neurotransmitter released in the brain
– Acts on the hypothalamus to increase appetite
– Triggers stomach contractions

Question 21

Melanocortin

Answer 21

chemical important in limiting food intake

Deficiencies of this receptor lead to overeating