Exam 3: Homeostasis : Hunger

Question 1

food supplies __ and __ needed for…

Answer 1

food supplies energy and nutrients needed for growth, maintenance, and repair of the body

Question 2

nutrients stored in 2 types of reservoirs

Answer 2

short-term store and long-term store

Question 3

glucose

Answer 3

principal sugar used for energy

especially in brain

Question 4

Glycogen

Answer 4

complex carbohydrate made of glucose molecules

sored for short-term in liver and muscles

Question 5

Glycogenesis

Answer 5

conversion of glucose to glycogen

regulated by pancreatic hormone, insulin

Question 6

Glycogenolysis

Answer 6

conversion of glycogen to glucose

controlled by glucagon

Question 7

Parts of short-term energy reservoir

Answer 7

glucose, glycogen, glycogenesis, glycogenolysis

Question 8

lipids

Answer 8

fats for long-term storage

deposited in adipose tissue

Question 9

Gluconeogenesis

Answer 9

if food deprivation prolonged, this occurs

converts fats and proteins to glucose and ketones (form of fuel)

Question 10

what does the brain prefer, glucose or ketones?

Answer 10

glucose

Question 11

parts of long-term energy reservoir

Answer 11

lipids and gluconeogenesis

Question 12

fasting phase vs absorptive phase

Answer 12

fasting: when digestive tract empty
absorptive: when tract is full

Question 13

Intermittent fasting example

Answer 13

wait to not eat for hours on end to be able to pull from the long-term reservoir (prolonged food deprovation)

Question 14

what does gut-brain axis control?

Answer 14

hunger and feeding behaviors

Question 15

glucoprivation

Answer 15

drop in blood glucose levels

triggers hunger

Question 16

information from glucodetectors in liver and mechanosensory receptors in stomach travel via ___ to the ____

Answer 16

vagus nerve

nucleus of the solitary tract (NST) in brainstem

Question 17

nucleus of the solitary tract (NST)

Answer 17

receives and integrates appetite signals from many sources

- important in feeding behaviors

Question 18

gastric distension detected by…

Answer 18

stomach

Question 19

gut brain axis informs brain of …

Answer 19

glucose levels

efferent fibers to the pancreas modulate insulin release

Question 20

hypothalamus

Answer 20

coordinates many systems to regulate hunger and feeding

Question 21

dual center mode of appetite control(2)

Answer 21

lateral hypothalamus and ventral hypothalamus

Question 22

lateral hypothalamus

Answer 22

promotes hunger

Question 23

ventral hypothalamus

Answer 23

regulates satiety

Question 24

lesions and excitability to lateral hypothalamus

Answer 24

lesion: animals stop eating
excitability: induced eating

Question 25

lesions and excitabaility in ventral hypothalamus

Answer 25

lesions: overeating stimulation: suppressed eating

Question 26

where is the paraventricular nucleus (PVN)

Answer 26

ventral hypothalamus

Question 27

VMH

Answer 27

sexual behavior in females AND hunger and feeding role

Question 28

arcuate nucleus

Answer 28

contains an appetite controller governed by several hormones

Question 29

all peptides from gut and fat arrive here and modulate eating depending on if they are anorexigenic or orexigenic

Answer 29

arcuate nucleus

Question 30

2 sets of neurons the arcuate system relies on

Answer 30

POMC neurons | NPY neurons

Question 31

POMC neurons

Answer 31

inhibit appetite and raise metabolism promoting weight loss | - does not release POMC

Question 32

what do POMC neurons release into the lateral hypothalamus ?

Answer 32

alpha melanocyte-stimulating hormone

Question 33

NPY neurons

Answer 33

stimulate appetite directly and inhibit POMC neurons

Question 34

NPY neurons 2 functions

Answer 34

- release NPY | - project to the PVN of ventromedial hypothalamus

Question 35

what are brainstem regions involved in when the pathway goes NPY to PVN

Answer 35

involved in autonomic nervous system functions

Question 36

what are brain regions involved in that go in pathway through POMC to lateral hypothalamus

Answer 36

involved in food seeking behavior

Question 37

ghrelin

Answer 37

released from GI system when digestive system is empty

Question 38

what does ghrelin bind to to stimulate eating behaviors

Answer 38

binds to receptors on NPY neurons in hypothalamus

Question 39

when are ghrelin levels a their highest?

Answer 39

when fasting | get sharp drop after eating

Question 40

what nervous system does ghrelin activate?

Answer 40

ANS - parasympathetic (rest and digest)

Question 41

ghrelin turns NPY on and what happens to the PVN?

Answer 41

it is turned off

Question 42

ghrelin goes from NPY neuron to POMC neuron turning POMC off so it cannot release alpha msh to lateral hypothalamus, what happens to the orexin neuron?

Answer 42

it is disinhibited and turned on

Question 43

orexin

Answer 43

peptide produced in the LH (lateral hypothalamus) that also increases feeding

Question 44

projections from arcuate go to 2 main areas, what are they?

Answer 44

orexigenic neurons and anorexigenic neurons

Question 45

orexigenic neurons

Answer 45

of lateral hypothalamus acts to increase appetite and food intake

Question 46

anorexigenic neurons

Answer 46

of paraventricular neurons act to decrease appetite and feeding

Question 47

where do orexin neuron axons project to?

Answer 47

brain regions involved in motivation and movement | - neocortex, PAG, RF, thalamus, and LC and spinal cord

Question 48

where do anorexigenic neurons project to?

Answer 48

brainstem regions (including NST) which regulates ANS function

Question 49

cholecystokinin (CCK)

Answer 49

intestines control rate of stomach emptying through release of CCK - directly suppresses eating by inhibiting the vagus - peptide released in response to the presence of fats

Question 50

Peptide YY3-36

Answer 50

released by small intestine after meal, proportional to calories ingested - works in opposition to ghrelin lots of calories = lots of PYY released

Question 51

CCK and PYY both signal

Answer 51

satiety

Question 52

long-term satiety signals from...

Answer 52

adipose tissue

Question 53

long-term satiety signal discovered in obese mouse ob/ob

Answer 53

fat cells are unable to produce hormone leptin

Question 54

anti-obesity hormone

Answer 54

increases metabolism decreases eating | - leads to false under recording of body fat composition