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Flashcards in Small Intestine Deck (31)
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1

How is chyme propelled through the small intestine?

Peristaltic waves

2

The presence of chyme in the SI stimulates the release of what?

secretin

3

Secretin is released from what cells?

S cells

4

S cells are found where?

In the duodenum

5

Secretin stimulates the release of what?

Bicarbonate and water

6

Secretin stimulates what cells to release bicarbonate and water?

Pancreatic acinar cells

7

Bicarbonate rich mucus is also released by what? Where?

Brunner's glands
duodenum

8

The bicarbonate-rich mucus does what?

neutralizes the gastric acid and makes the pH alkaline,
Protects duodenal wall from highly acidic gastric juice

9

What else does secretin do?

Decreases gastric motility

10

The presence of fat in the duodenum stimulates the release of what?

CCK - cholecystokinin

11

CCK is release by which cells where?

I-cells duodenum

12

CCK causes what to contract?

The gallbladder

13

CCK causes what to relax?

Sphincter of Oddi

14

CCK causes what to be excreted into the duodenum?

bile

15

CCK also stimulates what?

The pancreas to release enzymes which aid in the digestion of fat, starches, and protein

16

What enzyme completes the breakdown of starch into maltose?

Pancreatic amylase

17

Further digestion is assisted by enzymes from where in the small intestine?

Brush border of the enterocytes

18

Maltose breaks down what? Into what?

Maltose
2 molecules of glucose

19

Lactase breaks down what? Into what?

Lactose
Glucose and lactose

20

Sucrase breaks down what? Into what?

Sucrose
Glucose and fructose

21

What enzymes are found in the brush border of the enterocytes?

lactase, maltase, sucrase

22

Glucose is actively transported into the intestinal cells by what?

Sodium-glucose transporter

23

There is also a small amount of _______ that digests fat.

Intestinal lipase

24

Some fat is absorbed into the _________ which drain into what?

Central lacteals
Thoracic duct

25

What digests the polypeptides?

Intestinal peptidases

26

What are the proteolytic pancreatic enzymes? What do they produce?

trypsin
chymotrypsin
proelastase
carboxypolypeptidase
Produce: amino acids

27

Amino acids are _____ transported from the lumen into the intestinal cells by what?

Actively
Sodium-amino acid carrier

28

Fat breaks down to what in the SI?

Fatty acids and glycerol

29

Starch, glucose, and lactose break down into what in the SI?

Glucose
Fructose
galactose

30

Proteins breakdown into what in the SI?

Amino acids