Ward: Small and Large Intestine Secretion and Absorption Flashcards Preview

Block 3 Week 3 Meg > Ward: Small and Large Intestine Secretion and Absorption > Flashcards

Flashcards in Ward: Small and Large Intestine Secretion and Absorption Deck (55)
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1

Two components of the pancreas

acini
islets of Langerhans

2

Pancreatic secretions

proteolytic enzymes
carbohydrate enzyme (pancreatic amylase)
pancreatic lipase
cholesterol esterase

3

List the three proteolytic enzymes released from the pancreas

trypsin
chymotrypsin
carboxypolypeptidase

4

What activates trypsinogen to trypsin?
What activates chymotrypsinogen to chymotrypsin?

enterokinase
trypsin

5

Released from glandular cells and inhibits the activation of trypsin inside the secretory cells, in the acini and in the pancreatic ducts

trypsin inhibitor

6

In pancreatic acinar cells, enzymes are condensed into vacuoles and concentrated to form (blank), which can fuse with the apical membrane and rupture to release its contents

zymogen granules

7

Enzymes of the pancreas are secreted by (blank)

acini

8

When the pancreas releases pancreatic enzymes, it also releases (blank) and (blank)

water; bicarbonate ions

9

The (blank) and (blank) concentrations in pancreatic secretion are approximately similar to that of plasma, but (blank) ion secretion is lower. The (blank) ion secretion increases with secretion rate

Na+; K+; Cl-; bicarbonate

10

How is bicarbonate secreted from pancreatic cells?

Na/H+ exchanger pumps H+ in
H+ forms H20
H20 combines with CO2 to form bicarb which is shuttled out into the lumen in exchange for Cl-

11

As Cl- moves down its concentration gradient into the lumen, (blank) follows, which pulls water with it into the lumen.

Na+; H20

12

What is HCO3 secretion dependent upon?

The availability of Cl- in the lumen. Ultimately the opening of Cl- channels on the apical membrane.

13

As secretory rate increases, conc. of bicarb (blank)

increases

14

As concentration of bicarb in the lumen increases, the concentration of Cl- (blank)

decreases

15

4 stimuli important for stimulating pancreatic secretion

1. ACh
2. gastrin
3. CCK
4. secretin

16

released from parasympathetic vagus nerve terminals in the ENS

ACh

17

released during the gastric phase of the stomach

gastrin

18

secreted by duodenal mucosa when food enters the duodenum

CCk

19

secreted when low pH products enter the stomach (neutralizes pH)

secretin

20

ACh and CCK activate (blank), while secretin activates (blank)

Ca+ stores; cAMP

21

During the cephalic and gastric phases, ACh and gastrin cause relatively (blank) pancreatic secretion

little

22

Pancreatic secretion is increased considerably when chyme enters the duodenum, in response to the hormones (blank) and (blank).

CCK; secretin

23

released from S cells in the mucosa of the upper small intestine. The stimulus for release is gastric acid and long chain fatty acids.

secretin

24

The release of (blank) during the intestinal phase of pancreatic secretion increases the pH of the luminal contents so it is more optimal for pancreatic enzymes

bicarbonate

25

Released from I cells within the mucosa of the duodenum and upper jejunum. The stimulant that causes the release appears to be proteoses and peptones

CCK

26

Two important functions of the secretion of bile into the GI tract

1. emulsifies large fat particles into smaller ones
2. serves as a means of excretion of waste products

27

Two primary bile acids from cholesterol

cholic acid
chenodeoxycholic acid

28

Constituents of bile

Bile acids
Phospholipids
Cholesterol
Bile pigments
Inorganic ions

29

Major phospholipid found in bile

lecithins

30

Most important bile pigment

bilirubin