Hunger and Thirst

Question 1

why do obese people usually die of heart failure?

Answer 1

the heart is trying to pump blood to a large amount of tissue

Question 2

what uses our behavior to keep things balanced?

Answer 2

homeostatic systems

Question 3

what are the main homeostatic mechanisms?

Answer 3

negative feedback

Question 4

what happens if a set point is deviated from?

Answer 4

unwanted effects occur

Question 5

what is hypovolemic thirst?

Answer 5

stimulated by low extracellular/intravascular volume (low blood volume)

Question 6

what is osmotic thirst?

Answer 6

stimulated by high extracellular solute concentration (ingesting salt)

Question 7

how is hypovolemic thirst triggered?

Answer 7

loss of water volume

Question 8

what is baroceptors?

Answer 8

blood vessels and heart detect initial drop in BP—>brain activates thirst and salt craving( drinks water)—>arteries constrict to raise BP

Question 9

what happens in a vasopressin deficiency?

Answer 9

kidneys send more urine to bladder, resulting in chronic thirst

Question 10

What happens to the kidneys if blood volume decreases?

Answer 10

kidneys release renin which triggers formation of angiotensin II

Question 11

What are the effects of angiotensin II

Answer 11

1. blood vessels constrict
2. circumventricular organs trigger drinking
3. vasopressin is released
4. aldosterone is released

Question 12

what is the hypothalamus in control of?

Answer 12

eat, sleep, motivator, BEHAVIOR

Question 13

what does the circulating angiotensin II act in the subfornical organ to do?

Answer 13

to signal other brain sites to initiate drinking

Question 14

What is osmosensory neurons?

Answer 14

anterior hypothalamus respond to rise in blood osmotic pressure (sensitive to salt)

Question 15

what happens when cell membranes shrink

Answer 15

opens mechanical-gates Na+ channels

Question 16

How do OVLT neurons respond to increased osmotic pressure?

Answer 16

telling the pituitary gland to fire

Question 17

how does diffusion flow

Answer 17

high concentration to low concentration

Question 18

why don’t diets work?

Answer 18

the body thinks it is starving–>body freaks out and thinks, how it can conserve energy

Question 19

what can increase metabolism

Answer 19

activity/regular exercise

Question 20

glucose?

Answer 20

principle fuel for energy

Question 21

glycogen?

Answer 21

glucose is stored for short term in the liver

Question 22

glycogenesis?

Answer 22

converting glucose to glycogen, using insulin

Question 23

lipids?

Answer 23

long-term storage, fat tissue

Question 24

How does the brain decide when to start/stop eating?

Answer 24

brain integrates insulin and glucose levels with other signals

Question 25

signals that tell you to eat?

Answer 25

NPY, AGRP, Galanin, Orexin-A, and Dynorphin

Question 26

signals that tell you to stop eating

Answer 26

a-MSH, CRH/UCN, GLP-1, CART, NE, and 5-HT

Question 27

external factors of food intake?

Answer 27

- emotion - food characteristics - lifestyle behaviors - environmental cues

Question 28

what is leptin

Answer 28

keeps you skinny-appetite suppressant

Question 29

what creates leptin?

Answer 29

Fat cells to secrete leptin into the bloodstream

Question 30

what do defects in leptin production or sensitivity give?

Answer 30

false low report of body fat

Question 31

usually obese people are leptin what?

Answer 31

resistant

Question 32

overnutrition overworks the hypothalamus causing what?

Answer 32

obesity , diabetes, and heart disease bc of the damage to the hypothalamus

Question 33

What does Ghrelin do?

Answer 33

appetite stimulant- rises during fasting, drops after eating

Question 34

what is prader-wili syndrome

Answer 34

genetic disease that causes sense of never being full or satisfied( ghrelin levels are elevated)

Question 35

what is the hunger control center?

Answer 35

hypothalmus

Question 36

what is the lateral hypothalamus?

Answer 36

refusal to eat

Question 37

what is the ventromedial hypothalamus( don't eat)

Answer 37

lesions cause obesity(eat)

Question 38

VMH-lesioned animals do what?

Answer 38

overeat until they become obese

Question 39

what happens to the set point when we keep overeating?

Answer 39

the new set point keeps rising

Question 40

LH-lesioned animals what?

Answer 40

stop eating

Question 41

what happens to the set point when we keep undereating?

Answer 41

the set point keeps lowering

Question 42

two set of neurons in the hypothalamus have what?

Answer 42

opposing effects

Question 43

What neurons stimulate appetite and lower metabolism leading to weight gain?

Answer 43

NPY/AgRP

Question 44

What neurons inhibit appetite and increase metabolism leading to weight loss?

Answer 44

POMC/CART

Question 45

VMH lesions destroy what?

Answer 45

hunger-ending PVN

Question 46

LH lesions destroy what?

Answer 46

hunger-causing LHA

Question 47

Ghrelin stimulates what neurons?

Answer 47

AgRP neurons