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Flashcards in Terms/physiology Deck (27)
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1
Q

CCK

A

stimulates the Acinar cells to secrete digestive enzymes.
relaxation of sphincter of Oddi, contraction of the Gall bladder to release bile
Fats >12 Carbons in length (long chain) activate this enzyme. released from I cells of the duodenum. also thought to activate a vago-vagal reflex.

2
Q

4 levels of protection against pancreatitis

A
  1. enzymes in zymogen form
  2. enzymes stored in zymogen granules
  3. Geographical separation between pancreas and active enzymes (brush border enterokinase activates trypsin)
  4. trypsin inhibitor present in zymogen granule
3
Q

Secretin

A

acid induces this enzyme secreted by S cells of the duodenum; stimulates bicarb release from duct cells. tightly controlled and pH of 3 is maximal secretion.

4
Q

Low flow rate electrolyte composition of pancreatic secretion

A

High Na+, Cl-; Low K and HCO3

5
Q

High flow rate electrolyte compositin of pancreatic secretion

A

High HCO3-, Na+; low K and Cl

6
Q

Most important phase of pancreatic secretion

A

Intestinal phase-majority of the stimulation, in it is initiated by entry of chyme into intestinal lumen. S cells are activated by the acid (chemoreceptors). I cells detect fat and release CCK

7
Q

absorption of Bile and B12 occur in one part of the small intestine

A

ILEUM

8
Q

Jejunum

A

CCK, secretin, disaccharides, glucose transporters

9
Q

What cell secretes gastric lipase; what is the stimulation

A

chief cells; acetylcholine and gastrin stimulate secretion

10
Q

primary bile acids

A

made by liver;
-cholic acid, chenodeoxycholic
usually conjugate to glycine or taurine

11
Q

secondary bile acids

A

formed from intestinal bacteria

deoxycholic acid, lithocholic acid

12
Q

colipase

A

secreted by pancreas , activated by trypsin
binds to lipid droplets and anchors lipase to bile salt coated fat droplet (without this anchor pancreatic lipase is inhibited from binding of the bile coat)

13
Q

Bile salt activated lipase

A

catalyzes the hyrdolysis of carboxyl ester bonds in acylglycerols as well as other dietary fats like cholesterol esters , fat soluble vitamin esters and phospholipids (this lipase comprises 4% of total pancreatic juice protein)

14
Q

celiac sprue

A

impaired release of CCK in mucosal disease

15
Q

Chronic pancreatitis in relation to lipase

A

insufficient lipase secretion from the pancreas

16
Q

Zollinger-Ellison Syndrome

A

inactivation of lipase by low pH

17
Q

pancreatic phospholipase A2

A

digest phospholipids (more originates from biliary secretion rather than diet)

18
Q

Fat soluble vitamins

A

A, D, E and K
They need BILE!
pancreatic lipase removes esters from A and E
Vit D is transferred from chylomicrons to unoccupied serum Vit D binding proteins

19
Q

causes of fat malabsorption

A

1) intraluminal- decreased pancreatic lipase (CF, pancreatitis)or decreased enzyme activation (gastrinoma, pancreatitis)
2) mucosal- decreased bile acid concentration (ilieal resection, baceral overgrowth), decreased exposure to enterocytes (bypass), or defect in enterocyte (sprue)
3) lymphatic- abetalipoproteinemia, intestinal lymphangiectasia

20
Q

amylose

A

almost entirely alpha 1,4 linked linear chains of glucose

21
Q

amylopectin

A

both alpha 1.4 linked straight chains and alpha 1, 6 linked branch points (every 20 residues or so)
note: isomaltase cleaves the 1,6 linkages!

22
Q

SGLT1

A

Na+ and glucose or galactose on luminal side

23
Q

GLUT-5

A

fructose on luminal side

24
Q

GLUT-2

A

glucose or galacose on submucosa side
fructose on submucosa side

note: also Na, K atpase on submucosal side

25
Q

maltose

A

glucose +glucose

digested by sucrase or glucoamylase

26
Q

sucrose

A

glucose + fructose

digested by sucrase

27
Q

lactose

A

glucose + galactose