Brainscape's Knowledge GenomeTM

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


See full index

PSL301 > Digestion 3: Secretion > Flashcards

Digestion 3: Secretion Flashcards

1
Q

secretion

A

release of materials from cells that line the lumen of the GI

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

Where do secretion products end up?

A
  • ISF: paracine action
  • blood stream
  • lumen of GI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

where can goblet cells be found?

A

small & large intestines

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

which cells secrete mucus in the stomach?

A

Foveolar cells

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

largest endocrine system in the body is…

A 
enteroendocrine cells (EEC)
- cells that secrete hormones in the GI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

there are ___ types of EECs, and ___ types of GI hormones

A

18-20;

18-20

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

EEC function is influenced by…

A
  • GI contents

- ANS

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

describe EECs

A

single cells scattered throughout the length of the GI; secrete hormones

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

Goblet cells refer to…

A

mucus secreting cells that is shaped like a goblet (more like a comma “,”)

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

we take in about __ L of fluid a day, but there is __ L of fluid entering the GI tract in total due to…

A

2L;
7L;
secretions from the liver, pancreas, etc.

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

how much is secreted & absorbed in toe GI tract per day?

A

9 L total input

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

secretions into the GI include…

A
  • saliva
  • bile
  • gastric secretions
  • pancreatic secretions
  • intestinal secretions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

secretions into the GI = ___x the volume of ____

A

2x;

plasma

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

how are fluids removed from the GI?

A
  • absorption: small (main effect) & large intestines

- excretion: feces (small effect)

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

How is SA in the GI increased?

A

1) folds (3x)
2) hills & valleys (10x)
3) microscopic protrusions (20x)

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

SA increase method that can be found in the stomach

A

folds & valleys (no hills!)

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

rugae

A

folds on the inside of your stomach to allow expansion

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

valleys in the stomach =

A

gastric pits

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

gastric pits = opening to…

A

gastric gland

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

entrance to gastric glands are within the ___

A

rugae

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

anatomy: upper curve of the stomach

A

fundus

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

anatomy: antrum

A

nearly closed cavity located immediately before the stomach outlet. It is lined by mucosa and it does not produce acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

hills & valleys =

A 
hills = villi 
valleys = crypts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

SA increase methods that can be found in the small intestines

A
  • folds (plica or valvulae conniventes)
  • hills (villi)
  • valleys (crypts of Lieberkuhn)
  • microscopic protrusions (microvilli)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

differences between rugae and plica

A

plica is in small intestines, and is permanent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Crypts of Lieberkuhn extend to…

A

into the mucosa of the small & large intestines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

SA increase in large intestines

A

1) folds (haustra)

2) valleys (crypts of Lieberkuhn) - no hills!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

haustration

A

when food pushes the haustra outwards, creating bulges & increased SA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what causes haustra in the large intestines?

A

lack of resistance underlying the circular muscle in the large intestine during segmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what can haustration be classified as?

A

motility pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

microvilli is supported by…

why?

A

microfilaments;

allow microvilli to waves around to increase flow in small intestines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

celiac disease

A
  • immune disease where patients allergic to gluten

- microvilli are shorter → less SA → less absorption of nutrients → malnutrition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

where are goblet cells found in the small intestines?

A

between the epithelial cells making up the villi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

salivary gland is made up of…

A

1) parotid gland
2) sublingual gland
3) submandibular gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

saliva contains….

A
  • water
  • electrolytes
  • bicarb
  • mucus
  • IgA antibody
  • lysozyme
  • defensins
  • enzymes (salivary amylase & lingual lipase)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

function of saliva

A
  • protection
  • lubrication (try to prevent secondary peristalsis)
  • taste
  • digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

defensins

A

antimicrobial proteins that break bac’t cell walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

salivation is controlled by…

A

CNS (salivary center in medulla)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

conditioned response to salivation vs. unconditioned response

A

unconditioned: mechanoreceptors & chemoreceptors sense food in the mouth

conditioned response: see, smell, etc. becomes associated with taste of food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

conditioned response to salivation

A

sight/smell of food → cerebral cortex → salivary center (medulla) → salivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

salivary center is at…

A

pons / medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

effect on salivation: PNS vs. SNS

A

PNS: lots of watery saliva
SNS: small amount of thick saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

PNS control on salivation (process)

A

salivary center → CN VII, IX → salivary glands → watery saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

SNS control on salivation (proess)

A

thoracic spinal cord → pelvic nerves → superior cervical ganglion → post-ganglion fibres → salivary glands → thick saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what secretory cells are found in the stomach (order from lumen → gastric pit → gastric gland)?

A
  • mucous cells
  • parietal cells
  • chief cells
  • enterochromaffin-like cells
  • D cells
  • G cells
46
Q

mucous cells secrete…

A
  • mucus

- bicarb

47
Q

parietal cells secrete…

A
  • HCl

- intrinsic factor

48
Q

chief cells secrete…

A
  • pepsinogen

- gastric lipase

49
Q

enterochromaffin-like cells secrete…

A

histamine

50
Q

D cells secrete…

A

somatostatin

51
Q

G cells secrete…

A

gastrin

52
Q

physical layer of production in the stomach is ___, while chemical layer of production is ___

A

mucus;

bicarb

53
Q

Zollinger-Ellison syndrome

A

hyperacidic stomach that breaks down protective barriers and damages cells of the stomach

54
Q

pH of stomach lumen

A

2

55
Q

symptoms of ZE syndrome

A
  • GERD
  • nausea
  • pain
  • malnutrition
  • heartburn
56
Q

GERD

A

reflux of acidic chyme up the esophagus → dull chest pain

57
Q

function of HCl in stomach

A
  • kill bacteria
  • denature protein
  • activate pepsinogen
58
Q

function of intrinsic factor

A

binds to vit B12 → proper absorption in ileum

59
Q

vit B12 is also known as…

A

cobalamin

60
Q

How does parietal cells secrete HCl?

A

1) water dissociates to H+ and OH-
2) H+ is pumped into lumen by H/K-ATPase
3) OH- + CO2 → bicarb (catalyzed by CA)
4) bicarb leave on basolateral side using Cl/bicarb-exchanger
5) Cl- is pumped into lumen by Cl-transporter
6) Cl joins with H in lumen to form HCl

61
Q

Alkaline tide

A

build up of bicarb in ISF of stomach (parietal cells), so blood leaving the stomach is very basic

62
Q

how to activate pepsinogen?

A
  • Acid in stomach

- Pepsin (activates itself)

63
Q

function of gastrin

A
  • stimulates secretion of acid, histamine, pepsinogen, mucus

- increase stomach motility & mass movements (gastrocolic reflex)

64
Q

what stimulates release of gastrin?

A

peptides in the lumen of the stomach

65
Q

G cells are mostly found in ___ region of the stomac

A

pyloric

66
Q

2 ways in which gastrin can stimulate the release of HCl (and describe)

A

1) directly: gastrin → bloodstream → parietal cells → secrete HCl
2) indirectly: gastrin → bloodstream → enterochromaffin-like cells (ECL) → histamine → parietal cells → secrete HCl

67
Q

gastrin is responsible for ___ reflex

A

gastrocolic

68
Q

cause of ZE syndrome

A

hypersecretion of gastrin

- gastrin secreting tumour in pancreas

69
Q

which cells in the pancreas secrete things? where are they secreted into?

A
  • acinar cells
  • duct cells

secreted into pancreatic duct

70
Q

what do acinar cells secrete?

A
  • pancreatic amylase, lipase, nuclease, inactive protease
71
Q

proteases secreted by acinar cells

A
  • trypsinogen
  • chymotrypsinogen
  • procarboxypeptidase
  • proelastase
72
Q

duct cells secrete…

A
  • bicarb

- water

73
Q

pancreatic secretions into the small intestines is controlled by…

A

sphincter of Oddi

74
Q

How are pancreatic enzymes activated in the small intestines?

A

by enterokinase / enteropeptidase

75
Q

enterokinase

A

enzymes embedded in brush border that is required for the activation of proteases secreted by the pancreas

76
Q

how is bicarb secreted in the GI tract? (slide 20)

A

1) water + CO2 dissociate → bicarb + H (catalyzed by CA)
2) bicarb goes into lumen via bicarb/Cl-exchanger
3) H leaves the cell via NHE
4) NKCC transporter pumps stuff into lumen
5) Cl leaves cell via CFTR to lumen
6) Na leaves the cell to ISF via Na/K-ATPase

77
Q

Why is the blood leaving the pancreas / small intestines acidic?

A

bicarb is secreted in lumen while H is secreted into ISF

- this balances alkaline tide from stomach

78
Q

CFTR

A

cystic fibrosis transmembrane regulator

79
Q

how is water secreted in the GI tract?

A
  • Na attracted to lumen because it’s very negative from bicarb and Cl-
  • water is attracted to solutes in lumen
  • both transported to lumen via paracellular pathway
80
Q

only way for Cl to exit in the lumen is…

A

CFTR

81
Q

Why do people with cystic fibrosis have to ingest ____? Why?

A

pancreatic enzymes;

  • defective CFTR channels
  • no watery bicarb (only thick mucus from duct cells)
  • mucus blocks pancreatic duct
  • no enzymes can reach small intestines
  • no digestion
82
Q

bile is made up of…

A
  • bile salts
  • lecithin
  • cholesterol
  • bilirubin
  • bicarb
83
Q

where does bile come from?

A
  • synthesized by liver
  • diet
  • secretions from duct cells
  • remainders from body (e.g. bilirubin, cholesterol)
84
Q

bile salt recycling =

A

enterohepatic circulation

85
Q

bile salt recycling happens ___ x per day

A

5 - 15

86
Q

define: enterohepatic circulation

A

cycling between the liver and small intestines

- connected by hepatic portal vein

87
Q

primary bile acids are synthesized by…

A

liver

88
Q

secondary bile acids are syntheiszed by…

A

bacterial conversion in intestines

89
Q

bile acid → bile salt

A

conjugation with glycine or taurine (amino acids)

90
Q

difference between bile acid vs. bile salt

A

bile acid is lipophilic, so it wants to leave the lumen;

bile salt is conjugated, so can be soluble in the lumen

91
Q

process of bile salt recycling

A

1) liver makes primary bile acids
2) gets conjugated and enters small intestines
3) return to hepatic portal vein by…
- passive transport
- active transport
- bacteria mediated absorption (→ bile acids or continue → secondary bile acids)
4) goes back to liver

92
Q

bacteria mediated absorption

A

convert bile salt → bile acids so it can easily cross epithelial membrane

convert the bile salt → bile acid → secondary bile acid → reabsorbed or lost in feces

93
Q

fate of secondary bile acids

A

reabsorbed or lost in feces

94
Q

secondary bile acids (specific names and fate)

[MAYBE NOT ACCURATE]

A
  • deoxycholic acid (reabsorbed)

- lithocholic acid (lost)

95
Q

what hormone is released by the stomach?

A

gastrin

96
Q

what hormones are released from small intestines?

A
  • secretin
  • CCK
  • GIP
  • Motilin
  • GLP-1
97
Q

glucose-dependent insulintropic protein is secreted from…

A

K cells (mostly jejunum, some duodenum)

98
Q

why is GIP secreted?

A

in response to mixed meal (glucose, fat, protein)

99
Q

effect of GIP

A
  • increase insulin

- decrease acid

100
Q

motilin is secreted by…

A

M cells

101
Q

when is motilin secreted?

A

during fasting

102
Q

function of motilin

A

regulates migrating motor complex (MMC)

103
Q

secretin is secreted by…

A

S cells in duodenum

104
Q

function of secretin

A

decrease acid in small intestines

  • more pancreatic bicarb
  • less gastric acid secretion
  • less gastric emptying
105
Q

CCK is secreted by…

A

I cells in duodenum and jejunum

106
Q

CCK is secreted in response to…

A

fatty acids & AA in small intestines

107
Q

CCK causes…

A
  • contraction of gall bladder (more bile)
  • increased release of pancreatic enzymes (increase small intestines)
  • decreased gastric acid secretion & gastric emptying (slow stomach)
108
Q

GLP-1 (glucagon-like peptide-1) is secreted by…

A

L cells of the ileum

109
Q

GLP-1 is secreted in response to…

A

fatty acids & cabs in the small intestines

110
Q

effects of GLP-1

A
  • decreased gastric acid secretion & emptying (slows stomach)
  • increased insulin & B-cell growth; decreased glucagon
111
Q

GLP-1 causes feeling of…

A

satiation

PSL301 (29 decks)

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