GI Physiology

Question 1

Inner most layer of GI wall composed of epithelial cells specialized for absorption and secretion.

Answer 1

mucosa

Question 2

Layer of GI wall that consists of collagen, elastin, glands, and blood vessels

Answer 2

submucosa

Question 3

Layers of GI wall that provides motility for GI tract

Answer 3

Circular and Longitudinal Smooth Muscle

Question 4

Outer most layer of GI wall

Answer 4

serosa

Question 5

breaking food in small particles so they are easily broken down by enzymes. occurs in the mouth and stomach

Answer 5

mechanical digestion

Question 6

Enzymes in mouth that helps digest carbs and lipids

Answer 6

amylase (carbs) and lipase (lipids)

Question 7

First step of swallowing

Answer 7

cricopharyngeal relaxation

Question 8

What is different about the layers of the esophagus compared to the rest of the GI tract?

Answer 8

no serosa

Question 9

Enzymes that breakdown proteins in the stomach

Answer 9

pepsin and peptidase

Question 10

What are the three phases of digestion?

Answer 10

cephalic, gastric, intestinal

Question 11

Stimulates the release of pancreatic juice and weak contractions of the gallbladder during the cephalic and gastric phases of digestion

Answer 11

vagus nerve

Question 12

What induces the release of cholecstokinin?

Answer 12

fatty, protein-rich chyme

Question 13

What induces the release of secretin by the enteroendocrine cells of the duodenal wall?

Answer 13

acidic chyme

Question 14

What induces the release of pancreatic juice?

Answer 14

CCK and secretin

Question 15

Required for the absorption of B12

Answer 15

intrinsic factor

Question 16

Protects gastric mucosa from HCl

Answer 16

mucus

Question 17

Cells found in the body of the stomach that secrete pepsinogen

Answer 17

chief cells

Question 18

Cells found in the body of the stomach that secrete HCl and intrinsic factor

Answer 18

parietal cells

Question 19

Secreted by G cells in stomach in response to eating. Stimuli include proteins, distention of stomach, and vagal stimulation

Answer 19

gastrin

Question 20

Promotes H+ secretion by gastric parietal cells. Stimulates growth of gastric mucosa

Answer 20

gastrin

Question 21

Released from vagus nerve. Binds to receptors on parietal cells. Produces H+ secretion by parietal cells. Atropine blocks muscarinic receptors on parietal cells

Answer 21

ACh

Question 22

Released from mastlike cells in gastric mucosa. Binds to H2 receptors on parietal cells. Produces H+ secretion by parietal cells

Answer 22

histamine

Question 23

Most common cause of upper GI bleeding?

Answer 23

duodenal ulcers

Question 24

Type of motility where circular muscle contracts sending chyme in both directions. Intestine then relaxes allowing chyme to merge back together

Answer 24

segmentation

Question 25

Type of motility where longitudinal muscle contracts propeling chyme along small intestine. Simultaneously, portion of intestine caudal to bolus relaxes

Answer 25

peristaltic

Question 26

Controls contractile, secretory, and endocrine functions of GI tract. Sends information directly to smooth muscle, secretory, and endocrine cells

Answer 26

Intrinsic Innervation

Question 27

Name for the numerous openings of gastric mucosa where the gastric glands empty into

Answer 27

gastric pits

Question 28

Largest internal organ

Answer 28

liver

Question 29

Supplies majority of blood supply to the liver. Brings venous blood rich in nutrients from digestive tract. High blood flow

Answer 29

hepatic portal vein

Question 30

Name of structures where hepatocytes are in contact with blood in the liver. They fxn as capillaries and are arranged to form functional units (lobules)

Answer 30

sinusoids

Question 31

Found in people who abuse alcohol because alcohol suppresses citrate cycle and thereby impairs gluconeogenesis from aminoacids.

Answer 31

hypoglycemia

Question 32

What is the majority of cholesterol in the liver converted into?

Answer 32

bile salts

Question 33

Necessary for digestion and absorption of lipids in small intestine. Emulsify lipids to prepare them for digestion

Answer 33

Bile salts

Question 34

Detectable when the total plasma bilirubin > 2mg/dl

Answer 34

jaundice

Question 35

good diagnostic test for obstructive jaundice

Answer 35

conjugated bilirubin

Question 36

What is the pathophysiologi mechanism behind the development of varices and ascites associated with cirrhosis?

Answer 36

Cirrhosis leads to scar tissue which can obstruct blood and bile flow. Obstruction of hepatic venous blood flow can increase pressures

Question 37

Main duct (Wirsung) runs the entire length of pancreas. Joins CBD at the ampulla of Vater

Answer 37

pancreatic duct

Question 38

Acts on the acid producing parietal cells and indirectly decreases stomach acid production by preventing release of gastrin, secretin and histamine.

Answer 38

somatostatin

Question 39

only digestive enzyme secreted by the pancreas in an active form functions optimally at a pH of 7. hydrolyzes starch and glycogen to glucose, maltose, maltotriose, and dextrins

Answer 39

amylase

Question 40

Finger-like projections of the small intestinal mucosa

Answer 40

villi

Question 41

Tiny projections on luminal membrane of each intestinal cell. Give the apical region striated appearance called brush border

Answer 41

microvilli

Question 42

primary site for the removal of water and electrolytes and the storage of feces

Answer 42

transverse colon

Question 43

Tubular glands located in the mucosa of the large intestine that are responsible for mucus secretion

Answer 43

crypts

Question 44

What blocks the passage of feces and maintains continence?

Answer 44

contraction of internal anal sphincter and puborectalis muscle