Digestive System Overview

Question 1

Two basic functions of the digestive tract are _________________________.

Answer 1

(1) breaking down food and (2) absorbing nutrients

Question 2

Crossing from the lumen through all the layers of the GI tract, you pass through ____________________.

Answer 2

(1) the mucosal layer
(2) the epithelium, containing endocrine cells
(3) the lamina propria –an area characterized by loose capillaries, lymphocytes, and mesenchymal stroma
(4) muscularis mucosa, innervated by Meissner’s plexus
(5) submucosa
(6) inner circular muscle, innervated by Auerbach’s plexus
(7) outer longitudinal muscle, innervated by Auerbach’s plexus
(8) serosa

Question 3

All mucosa have some ___________ cells.

Answer 3

goblet

Question 4

Mucins are ___________________________.

Answer 4

• long molecules (usually about a million Daltons)

- heavily glycosylated (every third amino acid is a serine or threonine with a carbohydrate attached)

Question 5

The lamina propria is ____________ to the basal lamina.

Answer 5

deep

Question 6

The muscularis mucosa is ___________ to the lamina propria.

Answer 6

deep

Question 7

True or false: the submucosa is looser than the lamina propria.

Answer 7

False.

Question 8

What is the name of the muscular layer deep to the submucosa?

Answer 8

Inner circular and outer longitudinal

Question 9

All of the abdominal tissue is covered with _____________ epithelium.

Answer 9

serosal

Question 10

Meissner’s plexus is in the _____________. What does it do?

Answer 10

submucosa; it innervates the muscularis mucosa, stimulating contraction

Question 11

Where/what is Auerbach’s plexus?

Answer 11

It is a network of nerves in the inner circular and outer longitudinal muscle layers.

Question 12

Enteroendocrine cells reside in the ____________.

Answer 12

epithelium

Question 13

What hormones does Dr. Bendiak want us to know?

Answer 13

Gastrin
Secretin
Cholecystakinin

Question 14

Between the villi of the small intestine, there are small __________ at the base of the valleys.

Answer 14

crypts

Question 15

The _______________ is regular, like test tubes.

Answer 15

colon

Question 16

How do you distinguish between the small and large intestines (histologically)?

Answer 16

The large intestine has regular inlets that look like test tubes, while the small intestine has villi.

Question 17

Where, in the gastric glands, are the goblet cells, parietal cells, and chief cells? What does each do?

Answer 17

Goblet cells: near the surface of the gland –where the gland meets the epithelium; secretes mucus

Parietal cells: in the gland, but close to the surface; secrets HCl

Chief cells: at the base of the gland; secretes pepsinogen

Question 18

Enteroendocrine cells are at the ____________ of the gastric gland.

Answer 18

base (near the pepsinogen-secreting chief cells)

Question 19

The muscularis externae comprise the ________________.

Answer 19

inner circular and outer longitudinal muscles

Question 20

Which are further from the lumen, submucosal glands or accessory glands?

Answer 20

Accessory glands

Question 21

The serosal tissue around the esophagus is called _______________.

Answer 21

adventitia