Valencik > Makes me wanna die Flashcards
(133 cards)
1
Q
define “anorexigenic”
A
suppresses appetite
2
Q
define “orexigenic”
A
increases appetite
3
Q
define “satiation”
A
cessation of hunger
4
Q
define “satiety”
A
feeling full
5
Q
what are entereoendocrine cells generally?
A
endocrine cells of the GI tract & pancreas
6
Q
what are incretins?
A
gut hormones that stimulate insulin secretion
INcretins INcrease INsulin
7
Q
what are oxyntic cells?
A
gastric parietal cells that release gastric acid
8
Q
what are the 2 long-term signals in energy homeostasis?
A
leptin & insulin
9
Q
what are the 3 short-term signals in energy homeostasis?
A
GI tract hormones
hunger
satiety
10
Q
Leptin is secreted in proportion to what?
A
fat stores
11
Q
what makes less leptin be produced?
A
eat less > less body fat > less leptin
12
Q
how does insulin impact appetite?
A
decreases it
13
Q
what controls GI tract hormone release (2 things)?
A
size of meal
number of meals
14
Q
what are the 5 components of the hypothalamus that regulate food intake?
A
- lateral nuclei
- ventromedial nuclei
- paraventricular nuclei
- dorsomedial nuclei
- arcuate nuclei
15
Q
which nucleus of the hypothalamus that controls food intake is the most anterior?
A
arcuate nuclei
16
Q
which nucleus is the feeding center?
A
lateral nuclei
lateral makes you fateral
17
Q
which nucleus is the satiety center?
A
ventromedial
you feel full in your ventral region
18
Q
what happens if you stimulate the lateral nuclei?
A
increase hunger (hyperphagia)
19
Q
what happens if you destroy the lateral nuclei?
A
no urge to eat (inanition) > weight loss, muscle weakness, decreased metabolism
20
Q
what happens if you stimulate the ventromedial nuclei?
A
no urge or refusal to eat (inanition or aphagia)
21
Q
what happens if you destroy the ventromedial nuclei?
A
voracious appetite + continued eating > obesity
22
Q
what happens if you have a lesion in your paraventricular nuclei?
A
XS eating
like ventromedial nuclei
23
Q
what happens if you have a lesion in your dorsomedial nuclei?
A
less eating
like lateral nuclei
24
Q
what happens at the arcuate nuclei?
A
multiple hormones from from GI & adipose tissue converge to regulate eating & energy consumption
25
what are the 2 TYPES of neurons in the arcuate nuclei?
1. anorexigenic
| 2. orexigenic
26
name the anorexigenic neurons in the arcuate nuclei
POMC/CART
27
what do POMC/CART neurons produce?
alpha-MSH
&
CART peptide
28
name the orexigenic neurons in the arcuate nuclei
AgRP/NPY
29
what do AgRP/NPY neurons produce?
AgRP & NPY
30
which neurons are stimulated by ghrelin?
the orexigenic ones (AgRP/NPY) > increase food intake
31
which neurons are stimulated by insulin, leptin, & CCK?
POMC/CART (anorexigenic) > decrease food intake
32
which neurons are inhibited by insulin, leptin, & CCK?
AgRP/NPY
33
where does alpha-MSH act?
melanocortin MCR-3 & MCR-4 receptors on the PVN
34
where does CART peptide act?
an unknown receptor
35
what do alpha-MSH & CART peptide stimulate?
the PVN regulation pathways that inhibit eating & stimulate energy expenditure
36
what is the most common cause of obesity in kids? (can also play a role in anorexia)
MCR-4 mutations
37
what is the end result of alpha-MSH & CART peptide on food intake, sympathetic activity, & energy expenditure?
DEC food intake
INC symp activity
INC energy expenditure
(i.e. they signal that you have enough food/energy)
38
when do AgRP & NPY get released?
in response to low energy stores
39
what does AgRP antagonize?
MCR-4
| it blocks the signaling by alpha-MSH in the PVN
40
what does AgRP stimulate?
the release of GABA > inhibits POMC
41
what is the end result of AgRP release?
alpha-MSH cannot bind to MCR-4 > appetite increases
42
what can modulate AgRP actions?
gut endocrine factors
43
XS AgRP is assoc w/ what?
obesity
| it's orexigenic
44
where does NPY bind?
Y1 receptor
45
how does NPY act?
binds to Y1 receptor > hyperpol > inhibit neuronal fxn > interferes w/ VMN satiety
46
what can modulate NPY actions?
gut endocrine factors
47
what does NPY stimulation of food intake preferentially stimulate?
the desire for CARBSSSSS
48
how does NPY affect FA oxidation, carb oxidation, and FA synthesis?
DEC FA ox
INC carb ox
INC FA synth
49
what does agouti control in rodents?
coat color
50
what does AgRP colocalize w/?
NPY neurons in the ARC
51
what does AgRP have a fxnal relationship w/?
NPY
52
AgRP has antagonism w/ (___?___) in eating & body weight control
melanocortins
53
what family is NPY a part of?
pancreatic polypeptide family hormones
54
what are the 3 members of the pancreatic polypeptide family hormones?
1. NPY
2. pancreatic polypeptide (PP)
3. peptide tyrosine tyrosine (PYY)
55
where are the highest levels of NPY found?
in the ARC
56
what is one of the most potent orexigenic factors?
NPY
57
what happens to NPY when you lose weight?
it INCREASES (what an asshole)
58
what does NPY stimulate a craving for?
carbssssssssssss
59
where are orexin-expressing neurons found?
lateral & posterior hypothalamic areas w/ axonal projections throughout the brain
60
where are orexin receptors found?
throughout the CNS
61
what 6 things do orexins have a role in?
1. emotional & motivational aspects of eating
2. inc wakefulness & dec REM sleep
3. glucose ctrl
4. food intake
5. autonomic fxn
6. energy expenditure & metabolic rate
62
in the gut-brain connection, what is released in response to food (7 chemicals)?
1. GLP-1
2. CCK
3. PYY
4. PP
5. Oxyntomodulin
6. insulin
7. leptin
THESE ARE ANOREXIGENIC
63
what 3 chemicals are released to tell you that you're hungry?
1. ghrelin
2. galanin (GAL)
3. cortisol
64
what are the 2 adipocyte hormones?
1. leptin
| 2. adiponectin
65
T/F: leptin is orexigenic
FALSE
it's anorexigenic!
(if you're fat, you have enough food)
66
how does leptin regulate overall body weight
by limiting food intake
67
what do leptin concentrations directly correlate w/?
body fat
68
what does leptin promote the synthesis of?
alpha-MSH > suppresses hunger
69
how does leptin interact w/ NPY?
at first, it suppresses hunger via reducing inhibitory NPY effects on POMC nuclei
but then NPY levels return to normal
70
how does leptin impact food intake?
DECREASES it (it's anorexigenic)
71
what do leptin-deficient pts look like?
fat fatties
72
how do you treat leptin deficiency?
subQ injections of recombinant leptin
73
what is adiponectin thought to regulate?
BMR (energy)
74
how does adiponectin impact insulin sensitivity & FA oxidation?
increases both
75
what inhibits adiponectin activity?
adrenergic stimulation & glucocorticoids
76
what are adiponectin levels like in obese pts?
DECREASED
77
what are adiponectin levels like in pts w/ anorexia nervosa?
INCREASED
78
what are the adiponectin receptors & where are they?
1. AdipoR1 > muscle
| 2. AdipoR2 > liver & brain
79
where in the brain are AdipoR2 receptors?
only hippocampus & hypothalamic nuclei
| fxn unk
80
what is the largest endocrine organ?
the GUT
81
how many peptides does the gut express?
at LEAST 30
82
are incretins orexigenic or anorexigenic?
anorexigenic
83
what do incretins do?
INCREASE insulin secretion > stimulate a decrease in blood glucose
84
what does GLP-1 do (4 5 things)
1. INC glucose-dependent insulin secretion
2. DEC glucagon
3. DEC gastric acid secretion
4. DEC gastric emptying
5. DEC appetite
85
what cells express GIP?
enteroendocrine K-cells of the duodenum & proximal jejunum
| DJ K GIP
86
what inactivates GLP-1 & GIP?
dipeptidyl peptidase 4
| DPP-4
87
which cells express glucagon-derived peptides?
L-cells of the small intestine ("& elsewhere" whatever that means)
88
what are the glucagon derived peptides (there are 8) (not including glucagon)?
1. GRPP
2. MPGF
3. proglucagon
4. glicentin
5. oxyntomodulin
6. GLP-1
7. GLP-2
8. IP-1
89
look at slide 33 cause i am not making cards for that
hokay
90
what is the structure of oxyntomodulin?
37 AA peptide derived from proglucagon
| contains glucagon
91
what is the structure of glucagon?
29 AA
92
where is oxyntomodulin synthesized & released?
in the enteroendocrine L cells of the distal gut
93
when is oxyntomodulin secreted?
w/i 5-10 min of food intake
94
oxyntomodulin has (___?___) activity
incretin
95
what receptor does oxyntomodulin probably use?
the GLP-1 receptor
96
what does oxyntomodulin do in the brain?
suppress ghrelin effects
97
where is CCK expressed?
duodenum & jejunum
98
how many major active forms of CCK are there?
4
99
what form of CCK is found in human beans?
CCK-33
100
when is CCK secreted?
w/i 15 min after eating, peaks at 25 min
101
how long is the half-life of CCK?
1-2 min
102
what does CCK bind to?
GPCRs CCK-1 & CCK-2
103
when CCK binds its receptor, what 3 things happen?
1. gallbladder contracts
2. pancreatic enzymes released
3. gastric emptying inhibited
104
what is CCK synergistic w/?
leptin
| reduces food intake
105
does PP cross the BBB?
NOPE
106
where is PP expressed?
distal GI tract
107
when does PP increase?
after ~6 hours
108
what does PP increase in proportion to?
caloric intake
109
what does PP increase in response to?
ghrelin
motilin
gastric distention
110
how does PP impact ghrelin expression?
it DECREASES ghrelin
111
where is PYY produced & secreted?
from enteroendocrine L-cells of the ileum & colon
112
what is a potent regulator of PYY?
food composition
113
what leads to the highest PYY levels?
fat
114
what receptor does PYY work at?
Y2 mostly, but also Y1
115
what effect does PYY have on POMC & NPY?
INC POMC
| DEC NPY
116
what does PYY decrease or inhibit (5 things)?
1. ghrelin
2. gut motility
3. gastric emptying
4. pancreatic bicarb & protein secretion
5. gallbladder contraction
117
where does PYY have satiety effects?
ARC nuclei in hypothalamus
118
T/F: ghrelin is orexigenic
TRUE
119
how was ghrelin named?
GHR = growth hormone release
120
where does ghrelin act?
growth hormone secretagogue receptor (GHS-R)
121
what does GHRelin stimulate the release of?
```
growth hormone
(GHR = growth hormone release)
```
122
what can the preprotein of ghrelin alternatively be processed into?
obestatin
123
what secretes ghrelin?
stomach gastric oxyntic cells
small intestine
colon
124
what is the structure of ghrelin?
28 AA protein w/ acyl side chain (n-octanoic acid)
125
what about ghrelin is essential for GHS-R binding and its effects on food intake?
octanoylation
126
where does ghrelin act?
w/i the hypothalamus at ARC
| stimulates NPY & AgRP > inc GABA release > inhibit POMC nuclei
127
where is galanin expressed?
gut & brain
128
T/F: galanin is anorexigenic
FALSE
| orexigenic
129
how many AAs are there in galanin?
29
130
what does galanin bind?
GALR1 in the hypothalamus
131
how does galanin affect you?
makes you wanna EAT
132
how does the effect of galanin compare to NPY?
galanin's effect is small & short-lived
133
does galanin impact food preference?
nope
