Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 1: Alimentary System > 11. Regulation of Appetite > Flashcards

11. Regulation of Appetite Flashcards

1
Q

When does an individual perceive thirst?

A

1) Body fluid osmolarity is increased
2) Blood volume is reduced
3) Blood pressure is reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What the more potent stimulus of thirst?

A

Body fluid osmolarity increasing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the function of vasopressin/ADH?

A

It acts on the kidneys to regulate volume and osmolarlity of urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is vassopressin release regulated?

A

By osmoreceptors - which detect changes in osmolarity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where are osmoreceptors found?

A

Hypothalamous
Organ vasculosum
Subfornical organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are circumventricular organs?

A

Organs that are outside of the blood brain barrier or have an incomplete blood brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do the cells respond when the plasma is dilute?

A

They expand (vice versa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens when there is increased plasma osmolality?

A

Invokes drinking and ADH release
Increased ADH stimulates kidney to conserve water
Vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where are the receptors responsible for the relief of thirst?

A

Receptors in the mouth, pharynx and oesophagus

The relief of thirst by these receptors are short lived

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What hormone evokes the sensation of thirst?

A

Angiotensin II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does angiotensin II activate?

A

The subfornical organ neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the core priniciple behind thirst?

A

It all contributes to the homeostatic response to restore and maintain the body fluids at their normal level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is body weight homeostasis?

A

The balance between food intake and energy expenditure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where is energy intake and expenditure balanced?

A

Hypothalamous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What information from the periphery is interpreted by the hypothalamous?

A

Hormones and neural input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In terms of appetite what is the function of hypothalamous?

A

It judges how much food intake there should be compared to energy expenditure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of the arcuate nucleus?

A

Regulation of food intake and integrates peripheral and central feeding signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two neuronal populations of the arcuate nucleus?

A

Stimulates appetite
(NPY/Agrp neuron)
Inhibits appetite (POMC neuron)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does the arcuate nucleus have access to the perhipheral hormones?

A

It has an incomplete blood brain barrier

20
Q

What does NPY/Agrp affect?

A

It increases feeding - something in the blood binds to the receptors on neurons causing them to fire

21
Q

What do POMC neurons code for?

A

alpha-melanocyte stimulating hormone

22
Q

What does a-MSH bind to?

A

The MC4R receptor in the paraventricular nucleus

23
Q

What does activation of the MC4R receptor do?

A

It suppresses appetite

24
Q

What is the function of Agrp?

A

It acts as an endogenous antagonist to the MC4R receptor - blocks the receptor

25
Q

What can cause morbid obesity?

A

POMC deficiency and MC4-R mutations

Monogenic mutations

26
Q

What happens when you have a deficiency of leptin?

A

You become very hungry and put on a lot of body weight

27
Q

Where is leptin produced?

A

In white adipose tissues and circulates in plasma

28
Q

Where does leptin act on?

A

It acts on the hypothalamus regulating appetite (suppresses food intake) and thermogenesis (increasing energy expenditure)

29
Q

What are three aspects of the leptin regulatory loop that could lead to obesity?

A

Absent leptin
Regulatory defect - not able to detect increases in adipose tissue and increase the amount of leptin in response
Leptin resistance

30
Q

What the proportion of leptin to fat mass?

A

Leptin circulates in the plasma in concentrations that is proportional to fat mass

31
Q

Fat humans have…

A

high leptin

32
Q

Will injecting leptin solve obesity?

A

No. Obesity maybe due to a resistance to leptin. Leptin is present but doesn’t signal effectively

33
Q

How can leptin be used to treat obesity?

A

Only small number of people who have a congenital leptin deficiency.

34
Q

What is the mutation related to congenital leptin deficiency?

A

mutation in the ob gene

35
Q

What are the symptoms of leptin deficiency?

A

Severely hyperphagic and obese

36
Q

Why do you feel less hungry after a meal?

A

Hormonal signalling from the gut

37
Q

How many amino acids make up Peptide YY?

A

36

38
Q

What is the function of PYY?

A

suppresses appetite

39
Q

When does PYY increase?

A

After a meal - roughly in proportion to the calories consumed

40
Q

What effects does PYY3-36 have on the arcuate nucleus?

A

Inhibits NPY release
Stimulates POMC neurons
Decreases appetite

41
Q

How is PYY3-36 formed?

A

When 2 amino acids from PYY is cleaved off

42
Q

How many amino acids is ghrelin made from?

A

28

43
Q

What is special about ghrelins structure?

A

It has a fatty acid group bound to the third amino acid serine

44
Q

When does ghrelin levels increase?

A

Before a meal and decreases after a meal

45
Q

What effects does ghrelin have on the arcuate nucleus?

A

Stimulates NPY/Agrp neurons
Inhibits POMC neurons
Increases appetite

46
Q

What comorbidities is obesity associated with?

A

Depression, stroke, mycoardial infarction, bowel cancer etc

Year 1: Alimentary System (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions