GI Histology

Question 1

The layer closest to the GI tract lumen is the _

Answer 1

The layer closest to the GI tract lumen is the mucosa

Question 2

The mucosa is composed of three layers:

Answer 2

The mucosa is composed of three layers:
1. Epithelium
2. Lamina propria (loose connective tissue with glands)
3. Muscularis mucosae (smooth muscle)

Question 3

The layer exterior to the mucosa is the _

Answer 3

The layer exterior to the mucosa is the submucosa

Question 4

The submucosa is composed of _ connective tissue

Answer 4

The submucosa is composed of dense irregular connective tissue

Question 5

External to the submucosa is the _ layer

Answer 5

External to the submucosa is the muscularis externa

Question 6

The muscularis externa is composed of two different layers, the _ and _

Answer 6

The muscularis externa is composed of two different layers, the inner circular layer and the outer longitudinal layer

Question 7

Both the inner circular layer and the outer longitudinal layer of the muscularis externa are composed of _ muscle

Answer 7

Both the inner circular layer and the outer longitudinal layer of the muscularis externa are composed of smooth muscle

Question 8

The outermost layer of the GIT is the external layer composed of _ or _

Answer 8

The outermost layer of the GIT is the external layer composed of adventitia or serosa (loose connective tissue)

Question 9

(Adventitia/ Serosa) is a layer of loose connective tissue with mesothelial lining from peritoneum

Answer 9

Serosa is a layer of loose connective tissue with mesothelial lining from peritoneum

Question 10

An extra third layer of the muscularis externa can be found in _ region; its function is _

Answer 10

An extra third layer of the muscularis externa can be found in the stomach; its function is peristalsis

Question 11

Villi are found in the _ region; function is _

Answer 11

Villi are found in the small intestine; function is increasing surface area for absorption

Question 12

Goblet cells are found in _ regions and function to _

Answer 12

Goblet cells are found in small and large intestines and function to secrete mucus

Question 13

Peyers patches are _ ; they are found in the _ and have _ function

Answer 13

Peyers patches are aggregates of lymphoid tissue ; they are found in the ileum and appendix and have immune function

Question 14

Brunner glands are glands found deep in the _ layer of the _ ; they function to _

Answer 14

Brunner glands are glands found deep in the submucosa layer of the duodenum; they function to secrete alkaline substance

Question 15

Paneth cells are found in the _ and have _ function

Answer 15

Paneth cells are found in the jejunum and secrete lysozyme to break down bacterial cell walls

Question 16

The jejunum has large projections known as _

Answer 16

The jejunum has large projections known as plicae circulares
* These are spiral/circular folds that increase the surface area 2-fold for absorption

Question 17

What is the function of the following?

Answer 17

Question 18

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Question 19

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Question 20

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Question 21

What do these cells secrete?

Answer 21

Chief cells secrete pepsinogen

Question 22

What do these cells secrete?

Answer 22

G cells secrete gastrin

Question 23

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Question 24

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Question 25

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Question 26

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Question 27

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Question 28

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Question 29

Meissner's plexus is found in the _ layer

Answer 29

Meissner's plexus is found in the **submucosal layer**

Question 30

Auerbach's plexus is found in the _ layer

Answer 30

Auerbach's plexus is found in the **myenteric plexus**

Question 31

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Question 32

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Question 33

The hepatic lobule is hexagonal with _ situated at each point and _ in the middle

Answer 33

The hepatic lobule is hexagonal with **portal triads** situated at each point and the **central vein** in the middle

Question 34

Arterial and venous blood flows from the _ to the _ through the liver sinusoid

Answer 34

Arterial and venous blood flows from the **portal triad** to the **central vein** through the liver sinusoid

Question 35

(Fenestrated/discontinuous) endothelium is found in the liver

Answer 35

**Discontinuous** endothelium is found in the liver

Question 36

_ cells are found in the space of disse; they make collagen during liver repair, store fat, and store vitamin A

Answer 36

**Stellate cells** are found in the space of disse; they make collagen during liver repair, store fat, and store vitamin A

Question 37

Zone _ is closest to the portal triad and therefore performs the oxygen dependent processes of gluconeogenesis, cholesterol synthesis, amino metabolism, bile formation, ureagenesis

Answer 37

**Zone 1 (periportal)** is closest to the portal triad and therefore performs the oxygen dependent processes of gluconeogenesis, cholesterol synthesis, amino metabolism, bile formation, ureagenesis

Question 38

Zone _ is the site of glycolysis, glycogen synthesis, and lipogenesis

Answer 38

**Zone 3 (pericentral vein zone)** is the site of glycolysis, glycogen synthesis, and lipogenesis

Question 39

The lumen into which hepatocytes secrete bile is called _

Answer 39

The lumen into which hepatocytes secrete bile is called **bile canaliculus** * This is exocrine movement

Question 40

Hepatocytes play a role in immunity by producing _

Answer 40

Hepatocytes play a role in immunity by producing **C3 complement** (also Kupffer cells destroy pathogens)

Question 41

What flows in this direction?

Answer 41

Bile

Question 42

Where does the blood in the vessel come from?

Answer 42

25% from hepatic artery; 75% from portal vein

Question 43

What is the function of this in the hepatocyte?

Answer 43

Peroxisome- detoxification

Question 44

Villi are located in _ and function to _

Answer 44

Villi are located in **small intestine** and function to **inc surface area for absorption**

Question 45

Goblet cells secrete mucus; they are found in _ and _

Answer 45

Goblet cells secrete mucus; they are found in **small intestine** and **large intestine**

Question 46

Peyer patches are located in _ and _ and function to _

Answer 46

Peyer patches are located in **appendix** and **ileum** and function to **contribute to immune response**

Question 47

Brunner glands are found in the _ and function to _

Answer 47

Brunner glands are found in the **duodenum** and function to **secrete alkaline substance**

Question 48

The _ has a third layer of muscularis externa that functions in _

Answer 48

The **stomach** has a third layer of muscularis externa that functions in **peristalsis**

Question 49

Paneth cells are found in the _ and they function to _

Answer 49

Paneth cells are found in the **jejunum** and they function to **secrete lysozyme to break down bacterial cell walls**