Brainscape's Knowledge GenomeTM

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


See full index

Phys > Exam 4: Lecture 53: Gastrointestinal regulatory systems > Flashcards

Exam 4: Lecture 53: Gastrointestinal regulatory systems Flashcards

1
Q

What are the four GI functions?

A
  1. Contraction/relaxation of smooth muscle and sphincters
  2. Secretion of enzymes, fluid, and electrolytes
  3. Trophic effects on tissues
  4. Secretion of other GI peptides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The functions of the GIT are regulated by what substances?

A

GI peptides: hormones, neurocrines, and pancrines

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

If a GI peptide is secreted from an endocrine cell and distributed through circulation to a different tissue, what is it called?

A

A hormone

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

A neurocrine is a GI peptide secreted from what type of cell?

A

Neuron

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

A GI peptide that is secreted from an endocrine cell but acts within the same tissue is known as what?

A

A paracrine

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

What are the four GI hormones?

A
  • Gastrin
  • Cholecystokinin (CKK)
  • Secretin
  • Glucose-dependent insulinotropic peptide (gastric inhibitory peptide - GIP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the most important GI paracrine hormone?

A

Somatostatin

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

Somatostatin has major ______________ actions in the GIT.

A

inhibitory

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

T/F: GI neurocrines are released before an action potential.

A

False - they are released AFTER an action potential

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

What are the major neurocrines in the GIT?

A

Ach, NE, vasoactive intestinal polypeptide (VIP), gastrin-releasing peptide (GRP), enkephalins, neuropeptide Y, substance P

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

Promoting hydrogen ion secretion, stimulating growth of gastric mucosa, and increasing gastric motility are all functions of what GI hormone?

A

Gastrin

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

What cells secrete Gastrin?

A

G cells in the stomach

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

Which type of gastrin is secreted in response to a meal?

A

Little gastrin

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

When is big gastrin secreted?

A

In between meals

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

What two factors would inhibit gastrin secretion?

A

Low gastric pH and somatostatin

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

Describe the local vagal reflex.

A

GRP released from vagal nerves onto G cells

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

What type of cells secrete cholecystokinin (CKK)?

A

I cells of duodenal and jejunal mucosa

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

CKK is secreted in response to what substances?

A

Fatty acids, amino acids, and peptides

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

CKK has what function on the gall bladder?

A

Contraction of the gall bladder - helps to release bile

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

CKK has what impact on the pancreas?

A

Secretion of pancreatic enzymes and bicarbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is the secretion of bicarbonate from the pancreas important?

A

It neutralizes the digesta from the stomach by increasing the pH, allowing the digestive enzymes to work.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Does CKK activate or inhibit gastric emptying?

A

Inhibit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the overall action of CKK?

A

Promotes the digestion of food

23
Q

Which type of cells secrete secretin?

A

S cells of duodenum

24
Q

The secretion of secretin is in response to what?

A

H ions (drop in pH) and fatty acids in the small intestine

25
Q

Secretin promotes the secretion of what?

A

Pancreatic and biliary bicarb

26
Q

What other hormone is inhibited by secretin?

A

Gastrin from G cells in the stomach

27
Q

Gastric-inhibitory peptide is secreted by what type of cells?

A

K cells of duodenum and jejunum

28
Q

Glucose, amino acids, and fatty acids cause the secretion of what hormone?

A

Gastric-inhibitory peptide (GIP)

29
Q

GIP promotes the secretion of what substance?

A

Insulin

30
Q

(IV/Oral) glucose load is the only one to stimulate GIP production.

A

Oral

31
Q

Is a candidate hormone a true GI hormone?

A

No, they fail to meet at least one of the criteria.

32
Q

List the four candidate hormones.

A
  • Motilin
  • Pancreatic polypeptide
  • Enteroglucagon
  • Glucagon-like peptide 1
33
Q

When is motilin secreted?

A

During fasting

34
Q

When in pancreatic polypeptide secreted?

A

In response to ingestion of carbs, proteins and lipids.

35
Q

What is the effect of motilin?

A

Increase motility

36
Q

What is the effect of pancreatic polypeptide?

A

Inhibits pancreatic secretion of bicarb and enzymes

37
Q

When is enteroglucagon secreted?

A

In response to decreased blood glucose

38
Q

Enteroglucagon has what effect on the liver?

A

Increase glycogenolysis and increase gluconeogenesis

39
Q

What cells secrete glucagon-like peptide 1 (GLP1)?

A

L cells of SI

40
Q

GLP 1 has what effect?

A

Stimulates insulin secretion from pancreatic beta cells

41
Q

T/F: GI paracrines do not go into circulation, they act locally on tissues.

A

True

42
Q

What are the two GI paracrines?

A
  • Somatostatin
  • Histamine
43
Q

What cells secrete somatostatin and why?

A

D cells of GI mucosa; in response to decreased luminal pH

44
Q

What is the effect of somatostatin?

A

Inhibits the secretion of other GI hormones and gastric H ion secretion

45
Q

Where is histamine secreted from?

A

From H ion secreting area of the stomach

46
Q

What is the action of histamine?

A

Stimulates H ion secretion by gastric parietal cells

47
Q

Where are GI neurocrines synthesized?

A

Cell bodies of GI neurons

48
Q

Where are neuromodulators released from?

A

Post ganglionic non-cholinergic parasympathetic neurons

49
Q

Where is the satiety center located?

A

Ventromedial neucleus of hypothalamus

50
Q

What substance is released from the satiety center to decrease appetitie?

A

Pro-opiomelanocortin (POMC)

51
Q

Where is the feeding center located?

A

Lateral hypothalamic area (LHA)

52
Q

Orexigenic neurons release what substance?

A

Neuropeptide Y - increase appetite

53
Q

What substances influence anorexigenic neurons?

A

Leptin
Insulin
GLP 1
Peptide YY

54
Q

How does Leptin effect satiety?

A

Secreted by fat cells, stimulates anorexigenic neurons, increases energy expenditure.

55
Q

How does peptide YY effect satiety?

A

Direct effect on hypothalamus and inhibits ghrelin

56
Q

Which substances stimulates orexigenic neurons?

A

Ghrelin

Phys (13 decks)

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