liver and biliary

Question 1

4 x types of bile acids

Answer 1

there are 4 types of bile acids
• primary (i.e. formed in liver)
a. cholic acid 50%
b. chenodeoxycholic acid 30%

• Secondary (made elsewhere) in the colon, bacteria convert

c. cholic acid deoxycholic acid (15%)
d. chenodeoxycholic acid lithocholic acid (5%)

Question 2

secretin produced where?

Answer 2

secreted by s cells deep in glands of upper small intestines, in the mucosa of the duodenum

structurally similar to GLI, VIP, GIP

Question 3

what is substance p?

Answer 3

neuropeptide related closely to neurokin A.

first key responder to most noxious / painful stimuli.

1. potent vasodilator

Question 4

somatostatin produced where?

Answer 4

from D cells in the pancrease

Question 5

gastrin produced where?

Answer 5

produced by G cells in the gastric antrum & first part of duodenum

Question 6

somatostatin actions?

Answer 6

actions:
1. inhibits gastrin release
2. inhibits parietal cell function
3. inhibits release of insulin, glucagons

Question 7

action of secretin?

Answer 7

action ^ hco3- by pancreas and biliary tract by

1. producing alkaline watery secretions
2. augments cck
3. v gastric acid secretion
4. contraction of pyloric sphincter
5. inhibits gastric motility
6. stimulates pancreatic enzymes

Question 8

gastrin actions

Answer 8

1. stimnulate oxyntic & peptic cells to secrete gastric acid and pepsin
2. trophic effect on stomach and small/large intestine
3. • gastric motility
4. insulin secretion after protein meal

Question 9

gastrin stimulated by

Answer 9

distension of the antrum
peptides and amino acids in the antrum
vagal discharge by grp
hypercalcemia or adrenaline in the blood
massive bowel resection

Question 10

circulating levels of gastrin are high in which conditions?

Answer 10

zollinger-ellison syndrome

pernicious anaemia

Question 11

what stimulates the release of VIP?

Answer 11

stimulated by fat

Question 12

actions of VIP?

Answer 12

+ intestinal secretion of electrolytes and water
relax intestinal SM
peripheral vasodilation
inhibits gastric acid secretion
potentiates actions of Ach in salivary glands
VIPomas cause diarrhoea

Question 13

glutamine is consumed by?

Answer 13

rapidly diving cells e.g. gut mucosa, immunocytes, tumors

Question 14

is glutamine in parenteral feeds?

Answer 14

no as its unstable solution and breaks down to form toxic amounts of pyroglutamate and amonia

Question 15

when does the kidney consume glutamine?

Answer 15

metabolic acidosis

Question 16

how is arginine derived?

Answer 16

synth from kidney from gut derived citrulline