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Flashcards in GI Physiology Deck (60):
0

Most potent stimuli for gastrin secretion

Phenylalanine, tryptophan, methionine

1

Neurocrine from vagus nerve to G cells

GRP/Bombesin

2

GI Hormone classified as incretin

GIP, GLP-1, glucagon

3

GI hormone responsible for the interdigestive/migrating myoelectric complex

Motilin

4

Inhibits appetite; found at the ventromedial hypothalamus

Satiety center

5

Stimulates appetite; found at the lateral hypothalamic area

Appetite/ hunger center

6

Sends signals to satiety & hunger centers

Arcuate nucleus

7

Releases POMC to decrease appetite

Anorexigenic neurons

8

Releases Neuropeptide Y to increase appetite

Orexigenic neurons

9

Stimulates anorexigenic neurons, inhibits orexigenic neurons

Leptin (fat cells), insulin, GLP-1

10

Inhibit anorexigenic neurons

Ghrelin (gastric cells)

11

Inhibits ghrelin

Peptide YY

12

What is the most common stimulus of peristalsis?

Distension

13

What is the myenteric reflex?

Muscles upstream contract, muscles downstream exhibit receptive relaxation

14

What is the law of the gut?

Myenteric reflex + anal direction of peristalsis

15

How long does it take to transfer material from pylorus to ileocecal valve?

3-5 hrs

16

How long does it take to transfer material from ileocecal valve to colon?

8-15 hrs

17

Receptive relaxation of the stomach, vasovagal reflex mediated by

VIP

18

Capacity of the stomach

1.5 L or 400g of food

19

Gastric emptying duration

3 hrs

20

Inhibitor of gastric emptying

Fat

21

Urge to defecate, once rectum is

25% filled

22

Vomiting center

Medulla

23

Saliva, serous secretion

Parotid gland

24

Saliva, mixed secretion

Submandibular, sublingual glands

25

Saliva, effect of parasympa NS

Increase salivation, serous

26

Effect of sympa NS

Increase salivation, mucoid

27

Initial saliva is high in

Na, Cl

28

Final saliva is high in

HCO3, K

29

Hormone involved in absorbing Na at the ductal cells

Aldosterone

30

At high flow rates, saliva has

Low K; High Na, Cl, HCO3

31

At low flow rates, saliva has

High K; Low Na, Cl, HCO3

32

Contains mucus neck cells, parietal cells & chief cells

Oxyntic glands (body)

33

Contains G cells, mucus cells

Pyloric glands (antrum)

34

Secretes mucus & HCO3

Mucus cells, mucus neck cells

35

Secretes HCl & IF

Parietal cells/ Oxyntic cells

36

Secretes gastrin

G cells

37

Secretes serotonin

Enterochromaffin cells

38

Secretes histamine

Enterochromaffin-like (ECL) cells

39

Secretes pepsinogen

Chief/peptic cells

40

How do you absorb glucose & galactose from lumen to intestinal cells

SGLT-1

41

How do you absorb fructose from lumen to intestinal cell?

GLUT 5

42

How do you absorb glucose, galactose & fructose from intestinal cell to blood?

GLUT 2

43

What is the optimum pH for pepsin activity?

pH 1.0 - 3.0

44

Which is essential for protein digestion, pepsin or trypsin?

Trypsin

45

Bile salts inactivates pancreatic lipase. What pancreatic coenzyme is secreted to prevent this from happening?

Procolipase to colipase

46

What is the only product of TAG metabolism that is NOT hydrophobic?

Glycerol

47

What type of fatty acids go directly to the portal vein instead of the lacteals?

Short chain & medium chain FA

48

Main site for water reabsorption

Jejunum

49

Potassium is absorbed at

Large intestine

50

Potassium is secreted at

Small intestines

51

Primary ion secreted in the intestinal lumen

Chloride

52

Needed to absorb Vit B12

Intrinsic factor

53

Needed to absorb calcium

1,25 (OH)2 cholecalciferol/ Calcitriol

54

Needed to absorb iron

Vitamin C

55

Part of the metabolism of these vitamins involves colonic flora

Vit K, B1, B2, B12

56

Liver zone first to encounter toxins

Zone 1 (peripheral)

57

Liver zone susceptible to hypoxia

Zone 3 (centrilobular)

58

Ito cells

Space of Disse; Vitamin A storage

59

Kuppfer cells

Liver sinusoids; APC