GI 1

Question 1

What are the accessory organs of the digestive system

Answer 1

salivary glands, pancreas, liver, gallbladder

Question 2

Describe the order of the alimentary canal

Answer 2

mouth, esophagus, stomach, small intestine, large intestine

Question 3

Peritoneum

Answer 3

serous membranes within the abdominal cavity

Question 4

what is the purpose of the peritoneum

Answer 4

supports blood vessels, nerves, and lymphatic vessels

Question 5

describe the parietal peritoneum

Answer 5

inside the surface of the body wall

Question 6

describe the visceral peritoneum

Answer 6

surface of the internal organs

Question 7

Peritoneal fluid

Answer 7

produced by serous membrane lining, provides essential lubrication allowing sliding without friction or irritation

Question 8

intraperitoneal organs are located

Answer 8

within the peritoneal cavity

Question 9

retroperitoneal organs are located…

Answer 9

behind the peritoneum

Question 10

What is the function of the mesentery

Answer 10

prevents the GI tubes from getting tied up

Question 11

What disease does the mesentery play a role in?

Answer 11

Crohn’s disease- chronic inflammation of the GI tract

Question 12

What is the order of the GI histological layers? (lumen to outer)

Answer 12

transporting layer (epithelial), defense layer (immune and blood vessel cells), muscle layers (muscle cells), protection layer (connective tissue)

Question 13

What 3 layers make up the mucosa

Answer 13

mucosal epithelium, lamina propria, muscularis mucosae

Question 14

Describe the mucosal epithelium

Answer 14

enterocytes, endocrine and exocrine signals; GI stem cells

Question 15

what do enterocytes do

Answer 15

transport (take substances into cells and also secrete substances out)

Question 16

describe the lamina propria

Answer 16

connective tissue contains nerve fibers, vessels, and lymph nodes; wondering immune cells

Question 17

describe the muscularis mucosae

Answer 17

thin layer of smooth muscle, shape intestinal folds, move villi

Question 18

Which layer is the submucosa

Answer 18

defense layer

Question 19

describe the submucosa

Answer 19

loose connective tissue containing larger blood and lymph vessels (transporting absorbed nutrients)

Question 20

What is the submucosal plexus

Answer 20

Meissner’s plexus; nerve supply to the muscularis mucosae

Question 21

The Muscularis Externa is what layer of the GI tract?

Answer 21

muscular layer

Question 22

what makes up the muscularis externa

Answer 22

2 layers of smooth muscle: inner layer: circular, outer layer: longitudinal
myenteric plexus: located between 2 muscle layers

Question 23

peristalsis

Answer 23

move food along; mainly in the esophagus

Question 24

segmentation

Answer 24

mix food and break it down; mainly in the small and large intestine

Question 25

GI smooth muscle contraction frequency is set by:

Answer 25

basic electrical rhythm (slow waves 3-20 waves; set by pacemaker cells)

Question 26

What are the pacemaker cells in the GI called

Answer 26

interstitial cells of Cajal; modified smooth muscle cells that lie between muscle and nerve plexus

Question 27

What can influence contraction frequency

Answer 27

mechanical or chemical input

Question 28

what are features of the enteric nervous system that are similar to the CNS?

Answer 28

integrating center, glial cells, respond to many neurotransmitters and GI peptides to affect motility and secretion

Question 29

Elevated VIP (Gs coupled pathway) has been found in inflammatory bowel diseases, irritable bowel syndrome, what are some possible symptoms based on your knowledge on the receptors involved?

Answer 29

decreased motility (no smooth muscle contraction); increased secretion (vasodilator)

Question 30

Functions of saliva

Answer 30

softens and lubricates food, chemical digestion, taste, protection

Question 31

The acinar cells secrete what kind of fluid

Answer 31

a fluid that resembles extracellular fluid; isotonic; low in K, isotonic levels of Na+, Cl-, bicarb

Question 32

in the ductal cells, what is absorbed into the blood and what is secreted out of the blood into the oral cavity

Answer 32

absorbed= Na+, Cl- secreted= bicarb, K+

Question 33

during salivary stimulation...

Answer 33

ductal modification reduces, bicarb remains high by the action of secretagogues

Question 34

What is the resting pressure in the gastroesophageal junction

Answer 34

30 mmHg

Question 35

What are substances that reduce gastroesophageal junction pressure?

Answer 35

alcohol, caffeine, cigarette smoke, chocolate

Question 36

What is a pathological condition that is caused from a sphincter (esophageal) failing to close

Answer 36

GERD: gastroesophageal reflux disease; causes heartburn because stomach acid is traveling towards the esophagus

Question 37

What are conditions that increase the pressure in the gastroesophageal junction?

Answer 37

diseases and medications

Question 38

What is a pathological condition that is when the lower esophageal sphincter cannot relax (constricted)

Answer 38

Achalasia; difficulty swallowing, regurgitation of undigested food, chest pain because of the disruption of peristalsis

Question 39

What can cause achalasia?

Answer 39

degeneration of the nerve cells that innervate esophageal muscles

Question 40

How will VIP affect smooth muscle?

Answer 40

VIP will relax smooth muscle

Question 41

How will NO affect smooth muscle?

Answer 41

it will relax smooth muscle