Final Exam

Question 1

Which hormone is the only one considered to control extrinsic regulation of the GI tract? Where is this hormone made?

Answer 1

Aldosterone

Liver

Question 2

What type of substance is substance P, where is it located and what does it do in the GI system?

Answer 2

It is a peptide, located in sympathetic ganglia ,and it increases secretion and motility.

Question 3

What type of substance is VIP, where is it located, and what does it do in the GI system?

Answer 3

It is a peptide, located in parasympathetic ganglia, and it vasodilates blood vessels and relaxes smooth muscle/sphincters.

Question 4

This neurotransmitter reduces motility in the GI tract, is located in the gastric nerves, and is a non-peptide..what is it?

Answer 4

NO

Question 5

This neurotransmitter is located in postganglionic sympathetic neurons, is a non-peptide, and contracts smooth muscle in the GI tract…what is it?

Answer 5

ATP

Question 6

Which neurotransmitter in the GI tract increases secretions, is located postganglionic sympathetic neurons, and is a non-peptide?

Answer 6

Neuropeptide Y

Question 7

What does the body need in order for smooth muscles in the GI system to act as a syncytium?

Answer 7

Ca++ and the binding protein calmodulin as well as gap junctions.

Question 8

This nerve plexus is located in between the circular and longitudinal smooth muscle layers and controls muscular activity of GI system..what is it?

Answer 8

Myenteric plexus

Question 9

Where is the submucous plexus located and what does it control?

Answer 9

It is located in between the circular muscle layer and the submucosal layers. It controls mucous secretion and reabsorption.

Question 10

What is the main difference between a typical neuron and an enteric neuron?

Answer 10

Enteric neurons secrete neurotransmitters via varicosities located on axonal collaterals which affect a wider area than typical neurons.

Question 11

What are the three classification of enteric neurons?

Answer 11

Dogiel I
Dogiel II
Dogiel III

Question 12

Which enteric neuron can have multiple shapes and structures?

Answer 12

Dogiel III

Question 13

Which enteric neuron is very small, are motor neurons, and have short dendrites?

Answer 13

Dogiel I

Question 14

Describe a Dogiel II enteric neuron.

Answer 14

They are sensory neurons with long dendrites and large cell bodies.

Question 15

What part of the stomach is called the gastric pump and why?

Answer 15

The distal part with the corpus and antrum. Peristaltic waves break up and move food particles into the duodenum.

Question 16

Which endocrine secretions intrinsically control the GI system?

Answer 16

Secretin 
Gastrin
CCK
GIP
Motilin

Question 17

The enteric nervous system controls the _________ GI system.

Answer 17

Intrinsic

Question 18

Which nerves are responsible for controlling the GI Tract extrinsically?

Answer 18

Splanchnic nn.

Vagus nn.

Question 19

Which muscle layer contracts proximal to a cyme and which one relaxes?

Answer 19

Circular contracts

Longitudinal relaxes

Question 20

AcH and substance P ______ smooth muscle in the ________ part at the site of distention (cyme).

Answer 20

contract (circular muscle layer)

proximal

Question 21

Which neurotransmitters relax smooth muscle in the distal part (to the cyme) in the intestines?

Answer 21

NO
VIP
ATP