Lab_GIT Flashcards
stimulate acid
secretion
- Acetylcholine * Histamine * Gastrin
inhibits acid secretion
somatostatin
Physical barrier between the lumen and
epithelium
Mucous neck cell (Mucus)
Buffers gastric acid to prevent epithelial
damage
Bicarbonate
Activates pepsin; Kills bacteria
Parietal cell [Gastric acid (HCl)]
Vitamin B12 absorption
Intrinsic factor
Stimulates gastric acid secretion
Enterochromaffin-like cell (ECL)
[Histamine]
Protein digestion
Chief cell (Pepsin)
Stimulates gastric acid secretion
Antral G cells (Gastrin)
Fat digestion
Gastric lipase
Inhibits gastric acid secretion
Antral D cells (Somatostatin)
Tertiary amine belladonna alkaloid
ATROPINE
cholinergic antagonist
ATROPINE
Atropine competes with ________ at the muscarinic
receptors causing blockade of cholinergic
effects → ________ GI motility
Ach ; decrease
T/F: Atropine is reversible
T
Therapeutic use of atropine
Antispasmodic
indirectly acting cholinergic agonist
(acetylcholinesterase inhibitor)
NEOSTIGMINE
Neostigmine MOA: : carbamate esters by binding
with ______________ →
increases Ach at the synaptic cleft →
________ cholinergic effects → increase GI motility
acetylcholinesterase; increase
Selective anticholinergic with antispasmodic
activity
DICYCLOMINE
Inhibit muscarinic cholinergic receptors
DICYCLOMINE, N-HYOSCINE-BUTYLBROMIDE
Direct smooth muscle relaxant
DICYCLOMINE
No effect on gastric acid secretion
DICYCLOMINE
Use of DICYCLOMINE
Antispasmodics
Synonyms of DICYCLOMINE
Dicycloverine
T/F: N-HYOSCINE-BUTYLBROMIDE also Inhibit muscarinic cholinergic receptors
T
Use of N-HYOSCINE-BUTYLBROMIDE
Antispasmodics
Synonym of N-HYOSCINE-BUTYLBROMIDE
Scopolamine butylbromide
ANTIDIARRHEAL AGENTS
Opioid agonist – Loperamide, Diphenoxylate
Kaolin & Pectin (Kaopectate
inhibition of presynaptic cholinergic nerves
Loperamide, Diphenoxylate
Loperamide, Diphenoxylate are used as
treatment of diarrhea
Kaolin (hydrated magnesium silicate or attapulgite) + pectin
(indigestible carbohydrate derived from apples)
Kaopectate
adsorbent of bacteria, toxins and fluid → decreasing
stool liquidity
Kaopectate
Kaopectate is used as
Antidiarrheal
Bile salt binding resins adsorb bile salt (which cause secretory
diarrhea and __________
C. difficile toxin
Bile salt binding resins (e.g. cholestyramine,
colestipol) use
treat diarrhea caused by C. difficile and bile salts
regulatory peptide slows GI motility and
intestinal fluid secretion
Somatostatin, Octreotide
effective for diarrhea due to vagotomy,
short bowel syndrome
Somatostatin, Octreotide
Agents that Reduce Gastric Acidity
Antacids
* H2-receptor antagonist
* Proton pump inhibitor
Mucosal protective agents
- Sucralfate
- Prostaglandin analog (Misoprostol)
Laxatives
- Bulk
- Osmotic
- Stool softener
- cathartic