Physiology Intro

Question 1

What is the function of the GI epithelium?

Answer 1

Internal barrier between the body and world

Question 2

What are the main functions of the GI system?

Answer 2

Motility
Secrete
Digest
Absorb

Question 3

Name the 2 major plexuses in the gut wall.

Answer 3

Submucosal plexus

Myenteric plexus

Question 4

What is the function of the submucosal plexus?

Answer 4

Primarily controls secretion and blood flow.
Inputs chemo/mechano receptors
Outputs to smooth muscle and secretory cells

Question 5

What is the function of the myenteric plexus?

Answer 5

Primarily controls motility

Question 6

What is the action of the parasympathetic vs sympathetic systems on the GI tract?

Answer 6

Parasympathetic - excitatory

Sympathetic - inhibitory

Question 7

Name the two classes of GI Hormones.

Answer 7

Endocrine - released into circulation, travels to target cells e.g. Gastrin, Cholecystokinin
Paracrine - released locally and diffuses to target cells e.g, histamine, somatostatin

Question 8

What muscle is mainly found throughout the GIT and what are the exceptions.

Answer 8

Mainly smooth muscles

Except pharynx and anus are striated for control

Question 9

Name the muscle layers and their functions.

Answer 9

Muscularis mucosae - surface area
Circular muscle - reduce diameter
Longitudinal muscle - shortening

Question 10

What is the motility programme called?

Answer 10

Peristalsis