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Histology Exam III Material > Lower GI II > Flashcards

Flashcards in Lower GI II Deck (47):
1

______ hydrolyzes starch to form sugars

Amylase

2

Amylase is secreted by glands in the _______ as well as by the ______

mouth, pancreas

3

Starch is hydrolyzed to ________

disaccharides

4

Disaccharides are broken down to __________

monosaccharides

5

the breakdown of disaccharides occurs in _______ of _________

brush border of small intestine

6

Monosaccharides are absorbed by _________

enterocytes

7

The absorption of monosaccharides by enterocytes involves

energy-dependent mediator-specific carriers: Na+-dependent sugar glucose transporter-1 (SGLT-1)

8

Digestion of proteins begins in the ______

stomach

9

Proteins are hydrolyzed to

peptides

10

Digestion of proteins occurs through action of ______ (activated form of ______)

Pepsin (activated form of pepsinogen)

11

The digestion of proteins requires _____ environment of stomach, why?

proteins. Activation of pepsinogen to pepsin occurs in acidic enviroments

12

Polypeptide breakdown to peptides also occurs in the ______ and also occurs in the _______

stomach, small intestine

13

Polypeptide breakdown to peptides in the small intestine involves what enzymes secreted by the ______?

Secreted by the pancreas

-Trypsin
-Chymotrypsin
- Elastase
- Carboxypeptidase

14

Activation of pancreatic proteolytic enzymes is initiated by ______ (______) secreted by ___________

Enteropeptidase (enterokinase)

secreted by Duodenal enterocytes

15

Breakdown of oligopeptides to amino acids occurs in the

intestinal brush border

16

Transport of amino acids into enterocytes is via

carrier mediated process

17

Digestion of lipids begins in the _____

small intestine

18

Lipids enter the small intestine as _______

triglyceride droplets

19

________ emulsifies triglyceride droplets into smaller droplets and releases fatty acids and glycerol

pancreatic lipase

20

Fatty acids and glycerol combine with bile salts to form

micelles (2 nm in diameter)

21

Micelles can transport

-Fatty acids
- monoglycerides
- glycerol
- phospholipids
- cholesterol
- Vitamin A
- Vitamin K

22

_______ splits cholesterol into cholesterol and fatty acids

pancreatic lipid esterase

23

pancreatic lipid esterase splits cholesterol esters into

cholesterol and fatty acids

24

Micelles are _______ absorbed across ______ apical plasma membrane

passively, enterocyte

25

what is required for micelles to be passively absorbed across enterocyte apical plasma membrane

Requires fatty acid binding proteins (FABPs) in apical membrane

26

monoglycerides and glycerol are reesterified in the enterocyte ______ to form ______

SER, Triglycerides

27

The reesterification of monoglycerides and glycerol in the enterocyte SER requires _______ and _____ , which are found in

Acyl-CoA synthetase and acyltransferase

- found in membranes of enterocyte SER

28

Triglycerides recombine with proteins (from RER) to form ________

chylomicrons

29

Digestion of carbohydrates begin in the _______

mouth

30

Triglycerides recombine with proteins (from RER) to form

Chylomicrons

31

Chylomicrons are enclosed within membranes in __________, these membranes fuse to the plasma membrane and allow

Golgi Apparatus, exocytosis

32

Chylomicrons enter intercellular spaces and are taken up by __________ ________

central lacteals

33

Central lacteals are blind endings of lymphatic vessels within _______ that forms the content of the intercellular spaces within the _____

Lamina propria, villi

34

Lacteals dump into the large _____ _______ (_____ _____) that carry lymph form the gut tract

lymphatic network (cisterna chyli)

35

After being taken up by the central lacteals chylomicrons will later enter the blood via the

lymph ducts that enter the subclavian veins

36

Proteins and carbohydrates enter the blood vessels in the villi and are transported to the liver via the _____ ____ _____

hepatic portal system

37

Secretory activities of the GI tract are largely controlled by various _______ that, in turn, are under the influence of the contents of the GI tract.

hormones

38

Cholecystokinin site of secretion and in response of

-Upper intestinal mucosa (duodenum)
- Secreted in response to gastric contents

39

Targets and effects of cholecystokinin

- Acts on pyloric sphincter to slow down emptying of stomach

- Stimulates bile release from gallbladder

- Stimulates secretion of pancreatic enzymes

- Competitive inhibitor of gastrins.

40

Site of secretion of gastrin

pyloric-antral portion of stomach

41

Targets and effects of Gastrin

- Stimulates HCl production by gastric parietal ells
- Promotes growth of gastric mucosa
- Stimulates gastric motility
- Stimulates release of insulin by pancreatic beta cells

42

Site of Secretin secretion

- Epithelial cells of duodenum
- Stimulated by acid contents of stomach

43

Targets and effects of Secretin

- Enhances release of insulin by pancreatic Beta Cells
- Stimulates bicarbonate secretion by pancreas

44

The epithelium of the anus is ________ epithelium

stratified squamous epithelium

45

Skeletal muscle returns in the anal canal as the

external anal sphincter

46

What is the difference between internal and external hemorrhoids

internal are part of the internal hemorrhoidal plexus, which is internal to the internal anal sphincter and external hemorrhoidal plexus that is external to the external anal sphincter

47

What are hemorrhoids

Veins connecting the internal and external hemorrhoidal plexuses can become dilated and bulge the mucosa