MCAT Biology Digestive System

Question 1

Enzymes secreted by the mucosal cells lining the intestine.

Answer 1

Brush border enzymes

Question 2

Pepsinogen-secreting cells found at the bottom of the gastric glands of the stomach

Answer 2

Chief cells

Question 3

A hormone secreted by the small intestine (duodenum) in response to the presence of fats.

Answer 3

Cholecystokinin (CKK)

Question 4

__ promotes the release of bile from the gallbladder and pancreatic juice from the pancreas, and reduces stomach motility

Answer 4

Cholecystokinin (CKK)

Question 5

A type of lipoprotein; the form in which absorbed fats from the intestines are transported to the circulatory system

Answer 5

Chylomicrons

Question 6

One of the main pancreatic proteases it is activated by trypsin

Answer 6

Chymotrypsin

Question 7

The inner layer of smooth muscle in the wall of the digestive tract.

Answer 7

Circular smooth muscle

Question 8

When the __ the tube dameter of the digestive system is reduced

Answer 8

Circular smooth muscle

Question 9

The __ controls secretion and motility within the GI tract, and is linked to the Central nervous system

Answer 9

Enteric nervous system

Question 10

A hormone secreted by the small intestine (duodenum) in response to the presence of food

Answer 10

Enterogastrone

Question 11

__ causes a decrease in the rate at which chyme leaves the stomach and enters the small intestine

Answer 11

Enterogastrone

Question 12

A duodenal enzyme that activates trypsinogen (From the pancreas) to trypsin

Answer 12

Enterokinase

Question 13

A hormone released by the G cells of the stomach in the presence of food

Answer 13

Gastrin

Question 14

___ promotes muscular activity of the stomach as well as secretion of HCL, pepsinogen, and mucus

Answer 14

Gastrin

Question 15

Unicellular exocrine glands found along the respiratory and digestive tracts that secrete mucus

Answer 15

Goblet cells

Question 16

The sphincter that separates the final part of the small intestine (ileum) from the first part of the large intestine (the cecum)

Answer 16

Ileocecal valve

Question 17

The __ is kept closed typically to keep chyme in the small intestine as long as possible

Answer 17

Ileocecal valve

Question 18

The __ is stimulated to relax in the prresence of food in the stomach

Answer 18

Ileocecal valve

Question 19

The final (approximately 55%) of the small intestine

Answer 19

Ileum

Question 20

Specialized lymphatic capillaries in the intestines that take up lipids as well as lymph

Answer 20

Lacteals

Question 21

The outer layer of smooth muscle in the wall of the digestive tract is __

Answer 21

Longitudinal muscle

Question 22

When the longitudinal muscle of the GI tract contracts __

Answer 22

the tube shortens

Question 23

Also known as the cardiac sphincter, this marks the entrance to the stomach

Answer 23

Lower esophageal sphincter

Question 24

The layer of the epithelial tissue that lines body cavities in contact with the outside environment

Answer 24

Mucosa

Question 25

A network of neurons between the circular and longitudinal muscle layers in the gut; it helps regulate gut motility. Part of the enteric nervous system

Answer 25

Myenteric plexus

Question 26

The main duct of the pancreas. This carries the exocrine secretions of the pancreas (enzymes and bicarbonate) to the small intestine (duodenum)

Answer 26

Pancreatic duct

Question 27

Cells found in gastric glands that secrete hydrochloric acid (for hydrolysis of ingested food) and gastric intrinsic factors (for absorption of vitamin B12)

Answer 27

Parietal cells

Question 28

A protein-digesting enzyme secreted by the chief cells of the gastric glands

Answer 28

Pepsin

Question 29

__ is secreted in its inactive form and is activated by gastric acid. It is unusual in that its pH optimum is around 1-2; most of the enzymes in the body function best at neutral pH's

Answer 29

Pepsin

Question 30

A wave of contraction that sweeps along a muscular tube, pushing substances along the tube

Answer 30

Peristalsis

Question 31

The valve that regulates the passage of chyme from the stomach into the small intestine

Answer 31

Pyloric sphincter

Question 32

A hormone secreted by the small intestine (duodenum) in response to low pH. It promotes the release of bicarbonate from the pancreas to act as a buffer

Answer 32

Secretin

Question 33

The valve controlling the release of bile and pancreatic juice into the duodenum

Answer 33

Sphincter of Oddi

Question 34

The portion of the digestive tract that stores and grinds food. Limited digestion occurs here

Answer 34

Stomach

Question 35

The pH here is 1-2

Answer 35

Stomach

Question 36

A network of neurons found in the submucosa of the gut. It helps to regulate enzyme secretion, gut blood flow, and ion and water flow in the lumen. It is part of the enteric nervous system

Answer 36

Submucosal plexus

Question 37

The main protease secreted by the pancreas; __ is activated by enterokinase, and subsequently activates other pancreatic enzymes

Answer 37

Trypsin