8- Gastrointestinal Physiology

Question 1

What are the 6 primary gastrointestinal functions?

Answer 1

1. Absorption
2. Digestion
3. Excretion
4. Motility
5. Storage
6. Secretion

Question 2

From an engineering tube viewpoint, which area of the gastrointestinal system functions primarily as hydrolizer & lubricator?

Answer 2

Salivary glands

Question 3

Parasympathetic nervous system stimulation causes what actions?

Answer 3

Increase secretions
Increase motility
Decrease constriction of sphincters
Increase blood flow

Question 4

Sympathetic nervous system stimulation causes what actions?

Answer 4

Decrease secretions
Decrease motility
Increase constriction of sphincter
Increase blood flow

Question 5

Which nerves participate in sympathetic nervous regulation of the gastrointestinal tract?

Answer 5

Lumbar spinal nerve

Question 6

What are the 4 paracrine signaling molecules?

Answer 6

Histamine
Nitric oxide
Prostaglandins
Somatostatin

Question 7

What are the GI hormones?

Answer 7

CCK (cholecystokinin)
Gastrin
GIP (gastric inhibitory peptide)
Motilin 
Secretin

Question 8

List the neural signaling molecules

Answer 8

Acetylcholine 
ATP
CGRP (calcitonin gene related peptide)
Enkephalins 
GRP (gastrin releasing peptide)
Norepinephrine 
Neuropeptide Y
Substance P
VIP (vasoactive intestinal peptide)

Question 9

What is the primary secretion of the parotid glands?

Answer 9

Serous secretions

Question 10

What do the submandibular & sublingual glands secrete?

Answer 10

A mixture of mucous & serous secretions

Question 11

As salivary rate increases, which ions concentration in saliva decreases?

Answer 11

Potassium

Question 12

Which salivary gland is anatomically most inferior in the craniofacial complex?

Answer 12

Submandibular glands

Question 13

What are the functions of serous and mucous secretions?

Answer 13

Serous secretions: hydrolyzing

Mucous secretions: lubrication

Question 14

The parasympathetic nervous system increases salivary secretions by which of the following neurotransmitters ?

A. Norepinephrine
B. ATP
C. Vasoactive intestinal peptide
D. Neuropeptide Y

Answer 14

C. Vasoactive intestinal peptide

Question 15

What is the site of action of norepinephrine, leading to increased salivary secretions?

Answer 15

Beta adrenergic receptors

Question 16

Which gastric cell type is responsible for pepsinogen secretion?

Answer 16

Chief cells

Question 17

What is the function of somatostatin?

Answer 17

Decreased acid secretion

Question 18

Which of the following hormones increases H-K pump activity in the oxyntic gland?
A. Somatostatin
B. Gastrin
C. VIP hormone
D. Prostaglandin

Answer 18

B. Gastrin

Question 19

Which of the following is an effect of acetylcholine?
A. Decreased acid production
B. Decreased gastrin production
C. Increased gastrin production

Answer 19

C. Increased gastrin production

Question 20

What percentage of control & regulation of hydrogen ions is done in the gastric phase?

Answer 20

50%

Question 21

Which of the following is a stimulant for gastrin?
A. Carbohydrates
B. Proteins
C. Vitamin A

Answer 21

B. Proteins

Question 22

Which receptors is the site of action for acetylcholine from the vagus nerve resulting in release of hydrogen ions?

Answer 22

Muscarinic M3 receptors

Question 23

What is the location for release of exocrine pancreatic secretions?

Answer 23

Small intestine

Question 24

Which ion is secreted from the pancreas at a concentration that is many fold above what is in the plasma?

Answer 24

Bicarbonate

Question 25

Which phase of digestion accounts for the majority of the control and regulation of the exocrine pancreas?

Answer 25

Intestinal phase

Question 26

Which substance that increases secretion in the exocrine pancreas primarily utilizes a cAMP second messenger system?

Answer 26

Secretin

Question 27

Which substance is the primary mediator of release of bile stored in the gallbladder?

Answer 27

Cholecystokinin

Question 28

What is the concentration of bile salts in the gallbladder?

Answer 28

5-20%

Question 29

The Cystic Fibrosis Transmembrane Regulator can be checked by which glands clinically?

Answer 29

Sweat glands

Question 30

What can be found in the lumen portion of the duct of sweat gland of an individual with defected cystic fibrosis transmembrane regulator?

Answer 30

Sodium and chloride

Question 31

What is the mechanism of action of pilocarpine?

Answer 31

Cholinergic agonist

Question 32

What is the function of the stomach?

Answer 32

Blender acid

Question 33

Amylase works on which carbohydrate bonds?

Answer 33

Alpha 1,4 bonds

Question 34

Which of the following is a digestible form of carbohydrates in humans?
A. Amylopectin
B. Cellulose
C. Gums

Answer 34

A. Amylopectin

Question 35

The absorption of fructose across the apical membrane of an enterocyte most likely utilizes which receptor?

Answer 35

GLUT5

Question 36

What is the co transmitted substance utilized by PEPT1 to move across di and tri peptides?

Answer 36

Hydrogen ions

Question 37

Which hormone aids in the increase of calcium absorption across the enterocyte?

Answer 37

Vitamin D3

Question 38

SGLT1 allows the transport of how many sodium ions for each glucose molecule?

Answer 38

2

Question 39

Which transporter is requires for glucose to exit the basolateral membrane of cells in the small intestine?

Answer 39

GLUT2

Question 40

The amino acid transporters are divided according to which physical property?

Answer 40

pH

Question 41

What requires mixed micelles for the purpose of absorption?

Answer 41

Large lipids