GI secretions

Question 1

difference between exocrine and endocrine glands

Answer 1

exocrine= produce and secrete substances onto an epithelial surface by way a duct. secrete out of body
endocrine= secrete their products, hormones directly into blood rather than through a duct. secrete into body

Question 2

salivary glands (exocrine glands)
difference betwee major gland and minor glands
-composition
-function of serous cell and mucous cell
-function of salivary glands

Answer 2

major= 3 main pairs of major gland. secrete salvia via a duct
minor= lots of small glands
-each is a individual exocrine gland with it’s own duct

-99% water
-serous cell = produce watery fluid
-mucous cell= produce mucous

-tries to keep PH neutral
-helps dissolve chemicals in food

Question 3

gastric secretions (exocrine and endocrine).
-what are the exocrine secretions
-function of two gastric gland cell
1) pariental cell
2) cheif cell

Answer 3

gastric juice stomach acid

1) needed for absorbtion of vitamin B12.
secretes HCL which kills microbes
2) secretes pepsinogen (inative). need to be converted to pepsin (active) to break down proteins

Question 4

pancreatic secretions
1)percentage of endocrine vs exocrine secretions

Answer 4

1) endocrine (2%). exocrine (98%)

Question 5

pancreatic exocrine secretions
-water
1)PH of bicarbonate
2)function of enzymes pancreatic amylase, pancreatic lipase, proteases
3)how are the enzymes activated

Answer 5

1) alkaline
2) digest starches, digests fat, breaks down protein but secreted in inactive form
3) amylase and lipase and secreted in active form but require ions or bile for optimal activity.
-proteases is activated in duodenum

Question 6

pancreatic endocrine secretions (islet of langinham)
1) alpha cells
2) beta cells
3) delta cells

Answer 6

1) secrete glucagon
2) secrete insulin
3) secrete somatostatin inhibits gastrin release

Question 7

liver and gallbladder secretions
1) what do hepatocyte cells produce
2) PH of bile
3) function of bile
4) what stores bile and what duct is it released through
5) what organ produces bile and what duct is it released through

Answer 7

1) bile
2) alkaline
3) breakdown fats and neutralise gastric acid
4) gallbladder and released through cystic duct
5) liver and released through hepatic duct

Question 8

what are the three phases of the regulation of secretion
1) cephalic phase
2) gastric phase
3) intestinal phase - what hormones are released

Answer 8

1) smell, sight, taste of food activates CNS. prepares mouth and stomach for food

2) food enters stomach and stimulates stretch receptors. chemoreceptors in stomach detect increase in PH results in peristaliss and gastic jucie secretion

3) begins when food enters small intestine. inhibits gastric secretions. CCK and secretin

Question 9

function of pancreatic acini

Answer 9

secretes digestive enzymes