Brainscape's Knowledge GenomeTM

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


See full index

FBS1 physiology > salivary, gastric and pancreatic secretions > Flashcards

salivary, gastric and pancreatic secretions Flashcards

1
Q

what stimulation causes watery saliva

A

cholinergic (parasympathetic, ACh)
adrenrgic (symp +NA)
peptidergic

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

what nerve is the parasympathetic enervation os salivation through and what does it cause

A

chorda lingual nerve

fluid secretion, increased blood flow and oxygen consumption

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

what is salivary fluid secretion (but not blood flow) blocked by

A

atropine (possibly VIP or substance P co-release)

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

what does sympathetic stimulation cause

A

initial vasoconstriction then vasocilation

viscous, protein rich secretion by B-adenergic (less salivation)

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

how is glandular tissue organised

A

acinar cells surrounding small central lumen

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

what are the 2 main stages of saliva formation

A
  1. isotonic primary fluid (plasma-like electrolyte comp) formed by acinar cells (primary saliva)
  2. modified in duct system by reabsorption of NaCl and secretion of K and HCO3
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Maximum rate of saliva flow in humans

A

1 ml/min.g.

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

what are acinar cells

A
  • exocrine cells of pancreas
  • produce and trans digestive enzymes to duodenum
  • water/protein secretion via vesicular and granular pathways
  • primary secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what happens to saliva as it moves down the duct (strip/interlobular segment)

A

Na pumped out into interstitial = hypotonic saliva
K enters
H leaves
HCO3 enters

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

what are duct cells’ function

A

modifications of saliva—secondary secretion

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

production of saliva is NOT due to hydrostatic pressure, it is due to..

A

ionic pump involving processes and movement of water

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

what are the roles of acinat and ductal cells in salivary secretion

A
  • secrete proteins and electrolytes into oral cavity
  • lubricate - swallow
  • starch digestion: glycoproteins and amylase
  • highly fenestrated vasculature to guarantee sufficient nuteirts and water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the main glands involved in salivary secretion

A

parotid - stim by taste and touch

sublingual and submandibular glands

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

what are the transmission mechanisms that the salivary centre stimualtes

A
  • adrenergic (sympathetic)
  • NANC (VIP)
  • cholinergic (parasymp. inc blood flow by dilating)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does the parasympathetic nerve innervate (receptors and substrates)

A

VI –> VIP receptor –> NO and cAMP

ACh –> M1,3 receptor –> Ca

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

how much can blood flow increase by if stimulated for saliva

A

5-10 fold

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

what is the end effect when salivary centre is stimulated

A
  • contract myoepithelial cells around salivary duct
  • dilate blood vessels
  • IgA secretion -plasma cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

(describe the sympathetic nerve pathway for salivation )

A
  • release NA
  • act on B1 and a1 receptors
  • B1 modulate cAMP and NO levels
  • a1 modulates Ca levels
19
Q

(describe the parasympathetic pathway for salvation )

A
  • release VIP –> VIP receptor which modulates cAMP and nO)
  • ACh - M1,3 receptors - modulate Ca
  • interplay between cAMP and Ca = water/protein balance
20
Q

what are some physiological changes at old age contributing to hypo-salivation

A
  • gland atrophy –>
  • salivary gland hypofunciton –>
  • salivary secretion decreases
21
Q

what do chief cells secrete

A

pepsinogen - start protein digestion

22
Q

what do parietal cells secrete

A

HCl

23
Q

what cell type lines glandular stomach, gastric pits and tubular invaginations

A

columnar epithelium of surface mucosa cells

24
Q

explain funcitonal adaptations of stomach epithelium during HCl secretion

A
  • musous lining - protect and buffer by releasing HCO3
  • intrinsic factor (a glycoprotein) - combine w vit B12 - aid absorption in ileum
  • secretions include pepsin - protein digest
25
Q

what stimulates HCl secretion

A

ACh
histamine
gastrin

26
Q

what are the phases of gastric acid secretion

A

basal and stimulated–>
cephalic
gastric
intestinal

27
Q

describe propulsion, grinding and retropulsion

A
  1. bolus towards closed pylorus by peristalsis
  2. antrum churns trapped material
  3. most bolus pushed back to stomach
28
Q

how does the high fenestrated endothelium help nutrient supply and buffering

A
  • parietal secretes H (into gastric pit) and HCO3 which enters capillaries
  • arteroiles vasodilator due to NO and PGI2 to increase blood flow here
  • blood carries HCO3 to mucus barrier
29
Q

what happens when partial cells are activated

A

tubulovesicles become intracellular caniculi - secrete more H

30
Q

what does the mechanism of H+ secretion against enormous gradient require?

A
  • energy generated by oxyntic glands by aerobic resp
  • luminal H:K:ATPase
  • pump H to stomach lumen
  • high gradient in canaliculi
31
Q

what’s Soll’s three receptor modle

A

gastrin - CCK2
histamine - H2
ACh- M3

all secrte HCL

32
Q

what’s dimaline model

A

CCK2 and M3 on enterocytes- weak action

gastrin - CCK2 - ECL cell- histamine - binds to H2. Main secretion of HCL

33
Q

what are the two ways to inhibit further action of D cells and inhibitn of acid secretion

A
  1. H2 antagonist e.g. famotidine

2. proton pump inhibitor e.g. omeprazole

34
Q

what does somatostatin do and what is it released by

A

inhibit gastrin release by G cell

released by D cell

35
Q

what does gastrin releasing peptide (GRP) do

A

stimulate more gastrin release byG cells

36
Q

briefly describe the action of omeprazole

A

-selectively block proton pump - doesnt completely stop acid secretion (to continue digestion of food)

37
Q

what condition is omeprazole used for

A

peptic ulcer and reflux oesophagitis

38
Q

how does fat affect aid secretion

A

more fat = less acid secretion

fat requires bile salts from the liver

39
Q

what organ has the highest rate of protein synthesis

A

pancreas (exception of lactating mammary gland)

40
Q

what proteolytic enzymes are released by the pancreas

A 
trypsinogen
chymotrypsinogen
procarboxypolypeptidase
ribonuclease
deoxyribonuclease
41
Q

what enzymes (exp. proteolytic) are secreted by pancraese

A

amylase - starch and glycogen

lipase - fat into glycerol and FA

42
Q

what transporters are involved in pancreatic HCO3 secretion

A

NA:K-ATPase
Na:2Cl:K triporter
Na channel
Cl channel (lumina surface)

43
Q

what does protein ad fat digestion in the duodenum lead to

A

CCK secretion

acinar cells release proenzymes

44
Q

what does low pH in duodenum cause

A

HCO3 secretion

FBS1 physiology (10 decks)

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