Gastrointestinal Tract

Question 1

What is the “GI lumen”?

Answer 1

The inside of the GI tract

Question 2

What are the 3 parts of the small intestine in order?

Answer 2

1. duodenum
2. jejunum
3. ileum

Question 3

What stomach cell produces gastric acid?

Answer 3

Parietal cell

Question 4

Which organ secretes most of the digestive enzymes?

Answer 4

Pancreas

Question 5

What kind of epithelium is the lining of the mouth, esophagus and anus made of?

Answer 5

Stratified squamous epithelium

Question 6

What is added in the duodenum to return neutralize?

Answer 6

Bicarbonate

Question 7

What do parietal cells respond to?

Answer 7

Histamine, acetylcholine and gastrin.

Question 8

What are the chief cells responsible for?

Answer 8

When in contact with acid, they release pepsinogen which initiates the digestion of proteins

Question 9

What do G cells secrete and what is its purpose?

Answer 9

Gastrin

- stimulates the release of gastric acid from parietal cells

Question 10

What is the only secretion from the esophagus?

Answer 10

mucus for lubrication

Question 11

What are the two main enzymes in saliva?

Answer 11

Amylase: breakdown of carbohydrates
Lipase: breakdown of fats

Question 12

What does starch, glycogen, sucrose and lactose digest into?

Answer 12

Glucose, fructose, galactose

Question 13

How are proteins broken down in the stomach?

Answer 13

peptidase

Question 14

What do proteins digest into once they are broken down?

Answer 14

Amino acids

Question 15

What do triglycerides digest into and from what enzyme?

Answer 15

Lipase

- monoglycerides and fatty acids

Question 16

What is something our body cannot digest?

Answer 16

Cellulose / fibre

Question 17

What is tonic contraction?

Answer 17

Contractions maintained for a long time

• sphincters and upper stomach
• allows stomach to be low pressure so so contents can easily enter

Question 18

What are phasic contractions?

Answer 18

Short and rapid contractions

Question 19

What is peristalsis?

Answer 19

The circular contraction of muscles to move a food bolus towards it target

Question 20

What is segmentation?

Answer 20

The mixing and churning of food to increased surface area fro absorption

Question 21

What is cephalic phase? Is it sympathetic or parasympathetic?

Answer 21

When your body is anticipating food, it begins to increase motility
- parasympathetic

Question 22

What is gastric phase?

Answer 22

Increased motility stimuli: , distension, peptides and acidity in stomach
- swallowed food begins to activate gastric activity

Question 23

What is secondary peristalsis?

Answer 23

LOCAL CONTROL:

- distension of esophagus to clear out any leftover food

Question 24

Stomach lining consists of _____ to ________.

Answer 24

• Rugae folds

- Increase surface area

Question 25

Why is segmentation very important in the small intestine?

Answer 25

• it mixes chyme with intestinal juices

- brings it into contact with intestinal wall for absorption

Question 26

What is MMC and what is the function?

Answer 26

Migrating motor complex

• slow peristalsis wave that begins in stomach and ends in ileum
• moves undigested material to large intestine

Question 27

What initiates MMC and what stops MMC?

Answer 27

• motilin

- food