Body Energy Stores

Question 0

Metabolism controlled mostly through what mechanism

Answer 0

hormonal

Question 1

Maintenance of Body energy depends on what two things

Answer 1

1. how much energy we ingest

2. how much energy we consume (energy output - our metabolism)

Question 2

Much of our food intake is controlled by

Answer 2

Neuotransmitters, some hormones, other factors

Question 3

Body’s primary controller of complex vegatative function

Answer 3

Hypothalamus

Question 4

Lateral hypothalamic nucleus

Answer 4

causes behaviors that are associated with hunger

Question 5

Ventromedial nucleus

Answer 5

region associated with satiety

Question 6

dorsomedial nucleus

Answer 6

more directly involved in the control of metabolism

Question 7

arcuate nucleus

Answer 7

source of major inputs to the lateral and ventromedial hypothalamic nuclei

Question 8

Orexigenic chemicals

Answer 8

Neuropeptide Y
Ghrelin
AGRP

Question 9

anorexigneic chemicals

Answer 9

CCK
Seratonin
Melanocortin
CART
Leptin
GLP-1

Question 10

NPY

Answer 10

produced by arcuate nucleus
acts on lateral hypothalamic nucleus
NPY-1 receptor
increases food ingestion
most potent trigger of short term feeding behavior
release increased by ghrelin and decreased with leptin

Question 11

AGRP

Answer 11

antagonist of MSH
expressed by arcuate nucleus, 
work on lateral hypothalamic nuclei
also works on dorsomedial and ventromedial synapses, wher it blocks the anorexigenc actions of melanocortin
stimulated by ghrelin
inhibited by leptin

Question 12

Ghrelin

Answer 12

produced by parietal cells
endogenous ligand for GHS receptor
actions of ghrelin are independent of its ability to increase growth hormone secretion
increases as time after meal increases.
ingestion of food decreases grehlin release
acts on arcuate nucleus to increase NPY and AGRP
increases gastric motility

Question 13

CCK

Answer 13

released with presence of fat in duodenum
by chemoreceptors involved in control of intermeal duration.
activate ventromedial nucleus to induce satiety

Question 14

Seratonin

Answer 14

ventromedial nucleus
role in satiety
decrease apetite

Question 15

MSH

Answer 15

released from subset of neurons in arcuate nucleus
project to dorsomedial and ventromedial nuclei,
binds there to MC-4R receptor.
GPCR
decreasing feeding behavior.

Question 16

CART

Answer 16

arcuate neurons express Cart, released from synapses in the dorsoand ventromedial nuclei
anorexic effect

Question 17

Leptin

Answer 17

peptide hormone secreted by adipose tissue
needs receptor on cells of BBB to be transported to CSF
binds to receptor on neurons of arcuate nucleus
inhibits synthesis and release of NPY and AGRP,
increases release of melanocortin and CART

Question 18

GLP-1

Answer 18

induction of satiety

Question 19

Short Term control of eating, what is it?

Answer 19

How much we eat at a meal

Question 20

Short term control of eating, how it works

Answer 20

1. input from mechanoreceptors in the stomach and the intestine (distention) sent up through vagus nerve. causes inhibition of lateral nucleus, and excitation of ventromedial nucleus
2. CCK (presence of fats in duodenum) causes us to stop eating

Question 21

Intermediate Control of eating, what is it

Answer 21

how long between meals

Question 22

Intermediate control, how it works

Answer 22

1. intestinal and hepatic chemoreceptors
2. hypothalamic chemoreceptors
3. action of ghrelin

Question 23

Intestinal and hepatic chemoreceptors

Answer 23

chemoreceptros sensitive to one of the three nutrien groups and relay info to the brain.
via vagus nerve.
cause inhibition of lateral feeding areas
stimulation of medial satiety centers
important for determining time between meals (snack experiment)

Question 24

Hypotholamic chemoreceptors

Answer 24

set of neurons (glucostats, lipostats, aminostats) which sense content of those macromolecules - now believed that there is a common set of neurons for all 3 nutrients
inhibit lateral centers
stimulate medial centers
believed that glucokinase phosphorylates a K channel blocking efflux leading to AP, and belived to release 5HT

Question 25

Role of ghrelin in intermediat control

Answer 25

secreted from stomach
increases as time between meals increases, peak just before meal
acts on arcuate nucleus to increase NPY and AGRP in lateral and medial hypothalamic nuclei
NPY - stimulates hunger
AGRP - blocks satiety
NOTE - ghrelin has short term inhibition of feeding behavior,, but also plays role in meal initiation

Question 26

Long term control of Energy intake, what is it

Answer 26

How much do I weigh?

Question 27

Long Term control of Energy intake, how do we do it?

Answer 27

1. leptin is released in proportion to adipose present in body
2. leptin binds receptor at bbb to get into csf
3. leptin ginds receptros in arcuate nucleus and
   increases MSH and CART release in medial nuclei to produce satiety
   decreases NPY and AGRP release to prevent hunger
4. hypothalamic chemoreceptors and ghrelin may play role

Question 28

Causes of obesity

Answer 28

genetic (small portion)
leptin (we thought so, but not really, hypothalamus of obese person sees same amt of leptin as normal weight bc of desensitization of receptors)
GLP-1 (obese ppl have low GLP1).
Ghrelin (lower in overweight)
Melanocortin - different levels may lead to obesity
overweight ppl eat a diet higher in fats
(more calories per gram, doesnt spike metabolism the same way, and overweight pppl dont compensate for fat calories as well)

Question 29

Dz related anorexia

Answer 29

seen with illness, IL-1, IL-5, TNF

Question 30

Hypothalamic damage

Answer 30

damage to lateral nucleus, leads to loss of feeding behavior

damage to medial nuclei, leads to loss of satiety