Gastric motility and pancreatic function Flashcards Preview

Year 2 GI (JK) > Gastric motility and pancreatic function > Flashcards

Flashcards in Gastric motility and pancreatic function Deck (34)
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1
Q

Does mixing happen in the body or antrum of the stomach?

A

antrum

2
Q

Explain the differences in muscle and contractions in the body and antrum of the stomach

A

body - thin and weak

antrum - thick and strong

3
Q

What are 2 consequences of the pyloric sphincter contracting?

A

small amount of content enters the duodenum

contents not gone through are pushed back up and causes a further mixing of antral contents

4
Q

What is chime?

A

liquid slurry

5
Q

What is the peristaltic rhythm generated by and how many occur in a minute?

A

3

pacemaker cells

6
Q

Where are the pacemaker cells found in the stomach?

A

Longitudinal muscle layer and particularly in the top portion of the stomach

7
Q

What are slow waves?

A

random depolarisation and repolarisation which are driven by the pacemaker cells

8
Q

What is the basic electrical rhythm of the gut?

A

The slow wave rhythm

9
Q

How does the BER travel?

A

along the longitudinal muscle layer through gap junctions

10
Q

What determines the strength of contraction?

A

Frequency of action potentials

11
Q

What 2 things increase the force of contraction?

A

Gastrin and wall distension

12
Q

What 4 things inhibit motility?

A

acid, hypertonicity, fat, amino acid

anything signalling the stomach is emptying

13
Q

What cells secrete bicarbonate?

A

brunners glands - submucosal glands

14
Q

What 2 things promote bicarbonate secretion?

A

vagal + ENS reflex

secretin

15
Q

Where is secretin produced?

A

S cells in the duodenum

16
Q

Where is bicarbonate secreted from (organ)

A

pancreas and liver

17
Q

What mechanism is secretin production controlled by?

A

negative feedback

18
Q

Name the 3 parts of the pancreas

A

head, body and tail

19
Q

Give the relative anatomical positions of the head and tail of pancreas

A

head - in curve of duodenum

tail - to the spleen

20
Q

What makes up the exocrine part of the pancreas?

A

acinar cells and lobules

21
Q

What does the endocrine part of the pancreas secrete?

A

somatostatin to control the secretion of the other 2 compounds released - insulin and glucagon to control blood glucose

22
Q

Why is there an accessory pancreatic duct?

A

in case of blockage can still get the secretions into the duodenum

23
Q

Describe the make-up of the exocrine pancreas

A

acini cells make up individual lobules
Each lobule has an associated intercalated duct
Many intercalated ducts form an intralobular duct
Many intralobular ducts form the interlobular ducts which lead to the pancreatic duct

24
Q

How does the pancreatic duct enter the duodenum?

A

joins with the common bile duct to enter via the sphincter of Oddi

25
Q

What portion of the pancreas is digestion concerned with?

A

exocrine

26
Q

What do the duct cells secrete?

A

bicarbonate

27
Q

What do the acini cells secrete?

A

digestive enzymes

28
Q

How are the digestive enzymes stored in the acinar cells? Why?

A

As zymogens

to prevent autodigestion of the pancreas

29
Q

What enzyme controls the conversion of all other zymogens?

A

trypsin from trypsinogen

30
Q

How is trypsin formed?

A

from trypsinogen due to the enterokinase bound to the brush border of the duodenal enterocytes

31
Q

Give an example of some pancreatic enzymes and their roles

A

proteases- break down protein, nucleases-break down DNA, elastases-break down collagen, phospholipases-phospholipid–>FA, lipases-TAG–>FA and glycerol, alpha amylase - starch/glycogen–>maltose +glucose

32
Q

What stimulates secretin production and what does secretin do?

A

acid in duodenum

stimulates bicarbonate secretion from pancreas

33
Q

What stimulates CCK production and what does CCK do?

A

fat/amino acids in duodenum

zymogen release from acinar cells

34
Q

What stimulates neural control of pancreas?

A

organic nutrients in the duodenum