The Digestive System Flashcards Preview

PHGY1030 > The Digestive System > Flashcards

Flashcards in The Digestive System Deck (58)
Loading flashcards...
1

What are the 5 functions of the GI system?

1. propulsion
2. Secretion
3. Digestion
4. Absorption
5. Barrier Function

2

what are the accessory organs of the GI system?

1. pancreas
2. gall bladder
3. Liver

3

What are the 7 sphincters?

1. upper esophageal
2. lower esophageal
3. pyloric
4. ileocecal
5. colorectal
6. internal anal
7 external anal (voluntary)

4

name the major tissue layers from inside to outside of the digestive tract

1. mucosa
2. submucosa
3. musclaris

5

Where is the enteric nervous system located?

In the myenteric plexus which is located between the circular and longitudinal muscle in the muscle layer

6

what causes depolarization in the GI system?

1. stretch
2. acetylcholine
3. parasmypathetics

7

what causes depolarization in the GI system?

1. stretch
2. acetylcholine
3. parasympathetics

8

what causes hyper polarization in the GI system?

1. sympathetics
2. NE

9

Where is the myenteric plexus located?

located between the circular and longitudinal muscle in the muscle layer

10

what comprises the internal nerve plexus (enteric nervous system)?

1. submucosal plexus
2. myenteric plexus

11

what are the extrinsic nerves?

originate outside the digestive tract and innervate the various digestive organs

12

what causes hyper polarization in the GI system?

1. sympathetics
2. NE (released by sympathetic NS)

13

what does the PNS release in the GI system?

acetylcholine

14

what does the SNS release in the GI system?

NE

15

which reflexes proximal to distal or distal to proximal overrides the other ?

distal to proximal reflexes overide proximal to distal.

16

what do prokinetic agents do?

they increase motility

17

what are some pro kinetic agents?

1. serotonin agonist
2. dopamine antagonist

18

where does codeine bind? What does it cause ?

binds to opioid receptors which increases SNS and NE and causes constipation

19

what nerve plexus controls fluid secretion?

submucosal plexus (local control)

20

what are the 4 functions of saliva

1. moistening
2. lubrication
3. defence
4. digestion

21

How does the saliva function in defence?

1. lysozyme
2. IgA

22

what kind of digestion occurs with saliva

carbohydrate digestion only

23

how much saliva is released everyday?

1.5 L

24

does parasympathetic stimulation promote salivation?

yes. Sympathetic stimulation inhibits salivation

25

what are the function of gastric acid secretion?

1. bacteriocidal role: low pH
2. digestion of protein

26

what are the function of gastric acid secretion?

1. bacteriocidal role: low pH
2. digestion of protein by acid hydrolysis and denaturation
3. digestion of bone

27

what is a secretagogue?

helps stimulate acid secretion
1. Ach
2. Gastrin
3. Histamine

28

What does PGE2 do to secretion?

prostaglandin E2 is an anti-secretagogue and shuts down acid secretion

29

what do chief cells secrete?

pepsinogen which is a proenzyme that breaks down proteins

30

what is intrinsic factor and what cell secretes this?

- escorts vit B12 through the intestine to where it is going to be absorbed. It is secreted by the parietal cells