BIOL 0800 Reading- Chapter 15 Flashcards Preview

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Flashcards in BIOL 0800 Reading- Chapter 15 Deck (228)
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1

What acid is in the stomach?

HCl

2

What is pepsin?

Protein-digesting enzymes in the stomach

3

What two molecule types are typically not digested well by acid in the stomach?

Polysaccharides and fats

4

How much absorption of organic nutrients occurs in the stomach?

Virtually none

5

Where does most absorption of nutrients occur?

In the small intestine

6

What is the duodenum?

The initial segment of the small intestine

7

What is the jejunum?

The second segment of the small intestine

8

What is the ileum?

The third, longest segment of the small intestine

9

What are the three segments of the small intestine?

Duodenum, jejunum, ileum

10

What two organs secrete substances into the duodenum?

Pancreas and liver

11

How does the pancreas contribute to digestion?

Secretes digestive enzymes and a fluid rich in HCO3- to neutralize the acidic chyme

12

What does the liver do?

Secretion of bile to break down fast

13

What does the gallbladder do?

Stores secreted bile

14

What are the four layers of the GI wall?

Mucosa, submucosa, muscularis externa, serosa

15

What are the three layers of the mucosa?

Epithelium, lamina propria, muscularis mucosa

16

What is the submucosa?

Major blood and lymphatic vessels, submucosal plexus

17

What is the submucosal plexus?

Network of neyrons

18

What is the muscularis externa?

Circular muscle and myenteric plexus

19

How do circular muscles work?

Fibers oriented in circulate pattern around the tube so that contraction produces a narrowing of the lumen

20

What is the myenteric plexus?

Second network of neurons: innervated by nerves from the autonomic NS and has neurons that project to the submucosal plexus

21

What kinds of nerves innverate the myenteric plexus?

Autonomic nervous system

22

What is the serosa?

Thin layer of connective tissue to connect outer surface of tube to abdominal wall

23

What is a lacteal?

Single, bind-ended lymphatic vessel that is at the center of each villi

24

Most of the fat absorbed in the small intestine goes where?

Through the lacteals, to be emptied through the lymphatic systme into the thoracic duct

25

What is the hepatic portal vein?

The vein through which absorbed nutrients drain from the small intestine to the vena cava

26

What does the hepatic portal vein allow?

Material absorbed into the intestinal capillaries to be processed by the liver before entering general circulation: detox

27

What biological accounts for the liver's function as detox?

Hepatic portal vein: carries intestinally absorbed material through liver before returning it to capillary circulation

28

What are Peyer's patches?

Patches in the SI to secrete inflammatory mediators (cytokines) to alter motility of harmful substances not destroyed by acidity

29

What happens to amylase in the stomach?

It gets inactivated! Oh no!

30

What are the products of salivary and pancreatic amylase?

Maltose and short, branched glucose