Dukes' Ch. 43: Secretory Activities of the GI Tract Flashcards
What kind of cells produce histamine within the GI tract?
Enteroendocrine cells of the fundic stomach
Giving NSAIDs for long periods can cause ulcers to develop because many NSAIDs block (A) _____, resulting in failure of damaged cells to produce (B) _____.
This leads to failure to increase (C) _____ needed for cell repair.
(A) COX-1
(B) PGE and PGI
(C) blood flow
The alkalinity of pancreatic fluid is achieved by pancreatic duct cells that resorb (A) _____ ions from pancreatic acinar secretions and add (B) _____ ions to those secretions.
(A) Cl-
(B) Na+ and K+
Many enzymes produced by pancreatic acinar cells are secreted in an inactive form. What happens if they accidentally become activated within the acinar cells or the interlobular pancreatic ducts?
Digestion of body tissues leading to pancreatitis
Within a single functional unit of the liver the hepatocytes that are closest to the portal vein are receiving:
(A) the least oxygenated blood
(B) the most oxygenated blood
B
Bilirubin and many drugs are excreted via the biliary system. Generally, the process involves hepatocytes removing water-insoluble compounds bound to plasma albumin and increasing their water solubility by _____ and then releasing them into the bile canaliculus.
Hydroxylating them at various sites and conjugating them to a water-soluble compound like glucuronic acid.
What is the function of M or dome cells in the intestine?
Present antigens from the lumen to lymphocytes and dendritic cells residing in the laminal propria.
A clostridial bacterial toxin is ingested by a dog who got loose and obtained dinner from the neighbor’s garbage can.
The toxin activates receptors on (A) _____ cells located at the base of the crypts, which secrete serotonin in response to the toxin.
The serotonin acts on neighboring cells and causes (B) _____ channels in the basolateral membrane of (C) _____ cells to open.
(A) Enteroendocrine
(B) Calcium
(C) Crypt
Chloride is actively secreted into the lumen of the small intestine by _____ cells.
crypt enterocyte
Between meals, crypt cells are largely inactive.
Crypt secretion of chloride increases shortly after a meal causes distension of the stomach.
The crypt secretory process in this case is controlled by the (A) _____ which releases (B) _____ onto (C) _____ receptors of the crypt cells.
(A) Vagal parasympathetic
(B) Acetylcholine
(C) Muscarinic
Many horses harbor adult strongyle nematode parasites within their gut.
In their larval stage these parasites can migrate outside the digestive tract (not a long-term survival strategy for the parasite but they occasionally do this).
A young horse raised in relative isolation was put into a pasture with 50 other foals, all on a nonexistent to poor deworming program.
Within weeks this foal has a strongyle larva migrate into a tributary of the cranial mesenteric artery where the foal’s immune response kills the larva and the dead larva and immune cells block that small section of artery.
Blood flow to a section of intestine is greatly reduced. This causes which cells to die first?
Cells at the villous tip
