Salivary and gastric juices

Question 1

What are 3 roles of salivary secretions

Answer 1

Lubricate, protect and initiate chemical digestion

Question 2

What are the names of the major salivary glands and what type of saliva do each secrete

Answer 2

Parotid- serous, watery secretions, amylase for starch breakdown

submandibular- mixed serous and mucus

sublingual- mucus: thicker mucus dominant secretions for lubrication

Question 3

describe salivas composition

Answer 3

Water ( 99.5%), enzymes, electrolytes
mucin: lube, urea and uric acid (excretion)
secretory IgA: decrease microbial attachment to the epithelium.

Question 4

Give an example of a salivary gland dysfunction

Answer 4

sjogrens syndrome: autoimmune, destroys exocrine glands, dry eyes and dry mouth.

Question 5

How does HCL secretion occur

Answer 5

proton pump secretes H+, CA catalyses formation of HC03- which is exchanged for CL- that diffuses into the lumen of the stomach.

Question 6

What stimulates gastric secretion and what inhibits it.

Answer 6

ACH from Vagus, Gastrin from G cells and histamine from ECL cells

inhibited by somastatin from D cells

Question 7

Name and describe 3 gastric acid inhibiting drugs.

Answer 7

Omeprazole- proton pump
cimetidine- H2 receptor antagonist inhibits stimulus for acid secretion

atropine- inhibits muscarinic receptors and vagal stimulation of acid secretion

Question 8

Give an example of dysfunction of the gastric mucosa

Answer 8

Gastritis- commonly caused by infection by H. pylori

Question 9

what are the 3 gastric cells and what do they secrete

Answer 9

G-cells: gastrin
D-cells: somastatin
enterochromaffin-like cells (ecl) : histamine