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Flashcards in Physiology Deck (200)
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1

The large intestine is the principal site of dietary nutrient reabsorption. True/False?

False
Small intestine is the principle site of dietary nutrient absorption

2

What are the main functions of the large intestine?

Reabsorbs fluid + electrolytes
Stores faecal matter

3

The exocrine and endocrine "parts" of the pancreas are both part of the GI system. True/False?

False
Only the exocrine pancreas is part of the GI system

4

Name some accessory structures of the GI tract

Salivary glands
Pancreas
Liver
Gall bladder

5

Which muscle - smooth or skeletal - is predominant in the motility of the GI tract?

Smooth muscle

6

Which parts of the GI tract are under skeletal muscle control?

Mouth + pharynx
Upper oesophagus
External anal sphincter

7

Name two polysaccharides

Starch
Glycogen

8

Name two disaccharides

Sucrose
Lactose

9

Name three monosaccharides

Glucose
Fructose
Galactose

10

What are proteins broken down into?

Amino acids
Dipeptides
Tripeptides

11

The apical membrane of an enterocyte faces the lumen. True/False?

True

12

Which membrane of an enterocyte faces the blood?

Basolateral membrane

13

What are the 4 main layers of the GI tract wall, from innermost to outermost?

Mucosa
Submucosa
Muscularis externa
Serosa

14

What is the function of epithelial cells in the mucosa?

Absorption

15

What is the importance/function of the muscularis mucosa?

Can change shape/SA to facilitate absorption

16

What does contraction of circular muscle do to the lumen of the digestive tract?

Makes it narrower and longer

17

What does contraction of longitudinal muscle do to the lumen of the digestive tract?

Makes it shorter and fatter

18

What is the function of gap junctions between adjacent smooth muscle cells?

Enable slow wave of contraction to spread across smooth muscle sheet

19

Which cells drive slow wave electrical activity?

Interstitial cells of Cajal (ICCs)

20

What type of cells are ICCs?

Pacemaker cells

21

What must happen for ICCs to produce contraction?

Slow wave amplitude must reach threshold to trigger an action potential

22

The upstroke of the AP generated by ICCs is mediated by Na+ influx. True/False?

False
Mediated by Ca++ influx through Ca++ channels

23

The force of contraction in the GI tract is related to the number of action potentials discharged from ICCs. True/False?

True
The more APs fired, the greater the force of contraction

24

What determines the basal electrical rhythm of the digestive tract?

Slow wave electrical activity

25

All slow waves trigger contraction. True/False?

False
Threshold must be reached first

26

What is the net direction of luminal contents in the small intestine? Why?

Aboral direction
Fduodenum greater than Fileum

27

What is the net direction of luminal contents in the large intestine? Why?

Oral direction
Fdistalcolon greater than Fproximalcolon in order to allow some reabsorption to take place

28

What connects myenteric and submucosal plexi?

Interganglionic fibre tracts

29

What is the nervous system of the gut called?

Enteric nervous system

30

The parasympathetic system plays a bigger role in the enteric nervous system than the sympathetic system. True/False?

True