8.1 The Intestines Flashcards Preview

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Flashcards in 8.1 The Intestines Deck (25)
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1
Q

What are the folds in the intestines called?

A

Plicae circulares

2
Q

Why do contents move slowly through the intestines?

A

To allow maximal time for absorption

3
Q

What are the epithelial cells which line the intestines called?

A

Enterocytes

4
Q

What do goblet cells secrete?

A

Mucous

5
Q

What is the cell death of intestinal enterocytes called?

A

Anoikis

6
Q

What are the final products of carbohydrate digestion?

A

Monosaccharides

7
Q

What are the three most common monosaccharides?

A

Glucose, galactose and fructose

8
Q

What enzyme breaks up starch?

A

Amylase

9
Q

What transporter do glucose and galactose move through on the apical membrane of enterocytes?

A

SGLT-1

10
Q

What transporter does fructose move through on the apical membrane of enterocytes?

A

GLUT-5

11
Q

What is driving the absorption of monosaccharides?

A

Na-K-ATPase

12
Q

What transporter do all sugars move through on the basolateral membrane of the enterocytes?

A

GLUT-2

13
Q

Describe the basis of oral rehydration therapy

A

Na+, glucose and water are given to dehydrated patients to stimulate maximal water absorption in the intestines

14
Q

How are proteins broken down by the intestines?

A

The proteins must be broken down into tripeptides, dipeptides or individual amino acids by peptin and other proteases.

15
Q

How are tripeptides and dipeptides absorbed by the intestines?

A

Via a H+ co-transporter

16
Q

How are amino acids absorbed by the intestines?

A

Via a Na+ co-transporter

17
Q

What are Na+ channels in the intestine stimulated by?

A

Aldosterone

18
Q

How is Calcium absorbed by the intestines?

A

Enters enterocytes via facilitated diffusion and exits via Ca2+ ATPase. The process requires vitamin D

19
Q

How is Iron absorbed by the body?

A

Fe2+ is absorbed across the apical membrane passively. It binds to apoferritin and then moves across the basolateral membrane

20
Q

Where is vitamin B12 absorbed?

A

Terminal ileum

21
Q

What is segmentaion of the intestines?

A

Movement of the food back and forth in the intestine

22
Q

What is peristalsis?

A

Co-ordinated contractions that move the contents distally

23
Q

What is mass movement?

A

Moves contents rapidly towards the rectum

24
Q

What control is the internal anal sphincter under?

A

Parasympathetic control

25
Q

What control is the external anal sphincter under?

A

Voluntary (somatic)