GIT Physiology

Question 1

At what part of the GIT does the muscularis mucosae and submucosa begin?

Answer 1

It starts from the esophagus

It is absent in the mouth and pharynx

Question 2

the myenteric plexus is responsible for ……. While submucosal plexus is responsible for…..

Answer 2

Contraction of the smooth muscles of the GIT

Secretions and absorption

Question 3

Sympathetic fibres come from …… while parasym fibres comes from …..

Answer 3

T5-L2

Vagus n and pelvic splanchnic nerves

Question 4

In what layer of the GIT are the interstitial cells of cajal present?

Answer 4

The submuscularis

Question 5

Slow waves in the GIT caused by undulations in the rmp are produced by

Answer 5

Interstitial cells of cajal

Question 6

What are the pacemakers of the GIT?

Answer 6

Interstitial cells of cajal

Question 7

What are the factors that cause depolarization of the smooth muscles of the GIT?

Answer 7

Stretch or distension of the GIT
Parasym stimulation by the release of Ach
Hormones such as VIP, NO, Substance P

Question 8

Primary peristalsis wave in the esophagus is coordinated by …… while secondary is coordinated by …..

Answer 8

Vagus n

Intrinsic enteric nervous system

Question 9

What hormones promote intestinal motility?

Answer 9

CCK
Serotonin
Motilin
Insulin

Question 10

What hormones decrease intestinal motility?

Answer 10

Secretin and glucagon

Question 11

What types of movements occur in the small intestine?

Answer 11

Segmentation(contraction and relaxation)
Peristalsis
Myoelectric complex

Question 12

What are the types of movement in the large intestine?

Answer 12

Segmentation
Peristalsis
Mass movement

Question 13

What are the functions of gastrin?

Answer 13

It stimulates stomach motility and increases gastric emptying rate by decreasing pyloric sphincter tone.

Question 14

What acts as a cholinergic blocker in the GIT?

Answer 14

Atropine

Question 15

What are the main stimuli for vomiting?

Answer 15

Small intestine/ stomach irritation
Enteric virus or bacteria
Systemic irritation sensed by chemoreceptive trigger zone in the 4th ventricle
Abnormal stimulation of the vestibular apparatus

Question 16

What are the events that precede vomiting?

Answer 16

Reverse peristalsis
Filling of the stomach
Relaxation of UES

Question 17

What are the two types of Diarrhea?

Answer 17

Osmotic diarrhea(chyme moves too quickly through GIT and isn’t absorbed properly)

Secretory diarrhea(caused by increased secretion of solute into the gut e.g cholera toxin)

Question 18

Vomiting leads to ….. while diarrhea leads to ……..

Answer 18

Metabolic alkalosis and hypokalemia(due to loss of H and K ions)

Metabolic acidosis(due to loss of HCO3)