Grand Tour of the Alimentary Canal

Question 1

What is the enteric nervous system?

Answer 1

Submucosal (meisseners) + myenteric plexuses –> independent control of gut function

Question 2

What type of fibres are in the meissener’s plexus and where is it located?

Answer 2

Parasympathetic (in the submucosa)

Question 3

What type of fibres are in the myenteric plexus and where is it located?

Answer 3

Parasympathetic and sympathetic - in between he circular and longitudinal muscle layer

Question 4

What parasympathetic nerve innervates salivation?

Answer 4

Facial (VII) and glossopharyngeal (IX)

Question 5

Describe control of salivary secretion

Answer 5

Main innervation is via parasympathetic to increase salivation, but also from sympathetic NS to decrease

Question 6

What are the three main branches that come from the abdominal aorta?

Answer 6

Celiac trunk
Superior mesenteric aa.
Inferior mesenteric aa.

Question 7

What structures does the celiac trunk supply?

Answer 7

Foregut
Pancreas
Liver

Question 8

What structures does the superior mesenteric aa. supply?

Answer 8

Midgut

Question 9

What structures does the inferior mesenteric aa. supply?

Answer 9

Hindgut

Question 10

What veins drain into the portal venous system?

Answer 10

Gastric vv.
Splenic vv.
Superior mesenteric vv.
Inferior mesenteric vv.

Question 11

Describe blood flow through and out of the liver

Answer 11

1. Blood flow in: through hepatic portal vein and hepatic artery
2. Blood travels through the liver via capillaries
3. Blood flow out: all blood through the hepatic vein and into the IVC