The Gastrointestinal System

Question 1

____ is the chemical and mechanical breakdown of foods into smaller compounds that can be utilized by the body.

Answer 1

Digestion

Question 2

The gastrointestinal system consists of the organs of the ____, the pathway through the body that food travels while being digested and absorbed, as well as the accessory organs that release secretions necessary for digestion to occur.

Answer 2

alimentary canal

Question 3

The ____ release digestive enzymes that mix with the food to begin chemical digestion and lubricate the mouth.

Answer 3

salivary glands

Question 4

Swallowing is triggered when the chewed food, the ____, is sensed by the ____.

Answer 4

bolus; pharynx

Question 5

The bolus passes through to the ____ and then into the stomach aided by ____, a wavelike contraction of smooth muscle that moves digested material along the digestive tract.

Answer 5

esophagus; peristalsis

Question 6

Both chemical and mechanical digestion continue in the ____, a hollow organ separated from the esophagus by the ____ and from the small intestine by the ____.

Answer 6

stomach; esophageal sphincter; pyloric sphincter

Question 7

The pH of the stomach is maintained between 1 and 2 by the release of ____, which contains hydrochloric acid (HCI) as well as enzymes that begin the chemical digestion of protein.

Answer 7

gastric juice

Question 8

The contents of the stomach, now called ____, exit the stomach and enter the ____, where digestion is completed and reabsorption begins.

Answer 8

chyme; small intestine

Question 9

What are the 3 sections of the small intestine?

Answer 9

duodenum; jejunum; ileum

Question 10

When chyme enters the intestine, it signals the pancreas and gallbladder to release their digestive enzymes into the ____, the first part of the small intestine.

Answer 10

dudoenum

Question 11

____, created in the liver and stored in the gallbladder, is secreted into the duodenum through the ____.

Answer 11

bile; common bile duct

Question 12

The digestion of protein, carbohydrates, and fats occurs in the ____.

Answer 12

duodenum

Question 13

The small intestine is lined with ____ and ____, finger-like folds in the lining of the intestine that increase surface area to aid absorption.

Answer 13

villi; microvilli

Question 14

Approximately 90% of all nutrients will be absorbed in the ____, with the exception of Vitamin B12, which is only absorbed in the ____.

Answer 14

jejunum; ileum

Question 15

The digested material passes from the ilium through the ____, the pouch at the beginning of the intestine, into the large intestine.

Answer 15

cecum

Question 16

Water, salts, and vitamin K are absorbed in the ____, the proximal part of the large intestine.

Answer 16

colon

Question 17

Any remaining waste collects in the ____, the terminal section of the large intestine, to be expelled from the body through the ___, regulated by the action of the ____.

Answer 17

rectum; anus; anal sphincter

Question 18

____ involves enzymes or acids that break down food at the molecular level. Digestive enzymes are secreted by certain exocrine organs – including the pancreas, liver, and salivary glands – and by specialized cells in the lining of the stomach and intestines.

Answer 18

chemical digestion

Question 19

____ involves the physical breakdown of food into smaller pieces. Chewing, the churning process of the stomach, and the muscular action of peristalsis physically mash food particles apart, creating a greater surface area for chemical digestion to take place.

Answer 19

mechanical digestion

Question 20

So they do not digest the cells that synthesize them, enzymes are released in the inactive ____ form and are are rendered active only in the presence of other digestive compounds, such as HCI.

Answer 20

zymogen

Question 21

Enzymes that function best in acidic environments (low pH) are most active in the ____; enzymes that function best in alkaline environments (high pH) are most active in the ____.

Answer 21

stomach; small intestine

Question 22

____ lubricates the mouth; contains salivary amylase, which breaks down carbohydrates and starches; contains salivary lipase, which breaks down fats.

Answer 22

Saliva
salivary glands (mouth)

Question 23

____ digests protein by breaking bonds of amino acids.

Answer 23

Pepsin(ogen)
chief cells (stomach)

Question 24

____ sterilizes potentially harmful bacteria; causes proteins to denature; converts pepsinogen to pepsin.

Answer 24

Hydrochloric acid (HCI)
parietal cells (stomach)

Question 25

____ helps neutralize the acidic chyme as it enters the small intestine; aids in fat digestion and absorption by emulsifyng lipid particles.

Answer 25

bile

liver

Question 26

____ neutralizes chyme as it enters the duodenum.

Answer 26

pancreatic bicarbonate

pancreas

Question 27

____ maintains the mucosal lining of the stomach; protects the stomach walls from the digestive activity of HCI and other gastric enzymes.

Answer 27

mucus
Goblet cells (stomach)

Question 28

____ digests lipids and fats in the small intestine.

Answer 28

pancreatic lipase

pancreas

Question 29

____ includes lactase and other disaccharidases that breaks down lactose and other simple sugars; nucleases that break down nucleic acids; and peptidases that complete protein digestion and convert trypsinogen to trypsin.

Answer 29

brush border enzymes

microvilli (small intestine)

Question 30

____ digests proteins in the small intestine.

Answer 30

trypsin(ogen) (proteases)

pancreas and small intestine

Question 31

Absorption begins in the villi of the small intestine. Most nutrients absorbed in the small intestine move into the capillaries. The capillary network of the digestive tract carries blood to the liver through the ____. Digested fats are absorbed into the lymphatic system.

Answer 31

hepatic portal vein

Question 32

The hormone ____ stimulates gastric acid and mucosal secretion; increases motility.

Answer 32

gastrin

Question 33

The hormone ___ stimulates gallbladder to release bile; stimulates the pancreas to release pancreatic enzymes; inhibits gastric emptying and acid secretion.

Answer 33

CCK (cholecystokinin)

Question 34

The hormone ____ stimulates pancreas to release bicarbonate; inhibits gastric emptying; increases bile secretion.

Answer 34

secretin

Question 35

The hormone ____ induces hunger.

Answer 35

ghrelin

Question 36

The hormone ____ reduces hunger by signaling satiety.

Answer 36

leptin

Question 37

The hormone ____ inhibits gastric secretion and slows digestion.

Answer 37

somatostatin

Question 38

The hormone ____ inhibits gastric secretion and slows digestion.

Answer 38

somatostatin

Question 39

The hormone ____ stimulates uptake of glucose for conversion into glycogen; decreases blood glucose levels.

Answer 39

insulin

Question 40

The hormone ____ initiates breakdown of glycogen; increases blood glucose levels.

Answer 40

glucagon

Question 41

The hormone ____ initiates breakdown of glycogen; increases blood glucose levels.

Answer 41

glucagon