GI Tract (Colombo) - week 5

Question 1

True or False: The Pharynx has 4 histological Layers

Answer 1

False:

No muscularis mucosa or submucosa

1. Mucosa - Strat Squamos
2. Muscularis - Cir. & Longitudal
3. Adventitia

Question 2

Where is Tunica Adventita found

Answer 2

CT without Mesothelium, found in retro ograns where attached to other organs (serosa everywhere else)

Question 3

What is one defining histological charecteristic of the esophogus when compared to Vagina

Answer 3

The esophogeal glands (submucosa & propria) these glands add secretions to aid the passage of stuff down the tube.

Question 4

What is the common cause of GERD?

Answer 4

When the esophogeal sphincter cannot close properly. Stomach acid leaks into esophogus.

Question 5

What is the main protein and enzyme the stomach releases to digest food?

Answer 5

Protein: Pepsin
Enzyme: Lipase

Question 6

True or False:

The stomach is the main site of absorption

Answer 6

FALSE:

Main site of digestion

Question 7

Where does the epithelium changes from strat. squamos –> simple columnar in the stomach?

Answer 7

The Cardia or where the esophagus meets the stomach.

Question 8

Describe what is histologically different between the Cardia, Body/Fundus & Pylorus

Answer 8

Cardia: Pits < Glands
Body/Fundus: Long glands, pits more defined than in cardia
Pylorus: Pits > Glands

Question 9

Where are Chief cells and Parietal cells found in the stomach and what do the secrete

Answer 9

Body of stomach
Chief: Enzymes (pepsin & lipase)
Parietal: Gastric acid & Intrinsic factor

Question 10

What cells are found in the Gastric Pit

Answer 10

Surface mucous & a little Mucous Neck

Question 11

What cells are Found in the Gastric Gland

Answer 11

Parietal: HCL
Chief: Pepsin & Gastric lipase
G cells: secrete gastrin

Question 12

Which cell tells the rest of the stomach what is in it and how much of it there is

Answer 12

G cells

Question 13

Name the 3 phases of gastric acid secretion

Answer 13

1. Cephalic
2. Gastric
3. Instestinal

Question 14

Which part of the small intestine is responsible for digestion?

Answer 14

Duodenum (Bile, bicarbonate & digestive enzymes from pancreas)

Question 15

Where are circular folds, Villi & microvilli found?

Answer 15

Small intestine (circular folds - jejunum)

Question 16

Name the 2 histological layers that make up the circular folds

Answer 16

1. Mucosa

2. SUbmucosa

Question 17

Where are Peyers patches most commonly found?

Answer 17

Ileum, serve as parking garage fro immune cells

Question 18

Where in the small intestine does the majority of absorption occur?

Answer 18

In the Jejunum

Question 19

Remember Peyer’s patches are assoicated with the immune system

Answer 19

Great to know

Question 20

What 5 things are found in the Tunica Mucosa of the small intestine?

Answer 20

1. Epithelium (simple solumnar)
2. Enterocytes: Absorptive columnar cells
3. Goblet: Mucous production
4. Paneth cells: secrete antimicrobials & regulate immune response
5. Enteroendocrine cells: signals relating to digestion & transit

Question 21

Which cell found in the mucosa of the small intestine is responsible for absorption

Answer 21

Enterocytes

Question 22

How are lipids absorbed?

Answer 22

Bile acids - emulsify lipid droplets

Remember fats by pass the liver BC lymph circulation unlike carbs & proteins

Question 23

How is water absorbed?

Answer 23

Na+ goes out of intestinal lumen creating a high Na concentration out of cell, water diffuses form the lumen into intercellular space and eventually into capillary blood.

Question 24

If your digestive system is unable to absorp water, what symptom is most likely to be felt by the body?

Answer 24

Diarrhea - mostly water but takes important nutrients out with it.

Question 25

Name the 4 parts of the colon

Answer 25

Cecum, colon, rectum & anal canal

Function: absorb water & electrolytes
secrete bicarbonate & mucous, storage of feces

Question 26

Where is Villi NOT Found throughout the intestines

Answer 26

Not found in the COLON

Question 27

In what direction do Taeniae coli contract?

Answer 27

Length wise - aid in moving things along