Module 17: The Digestive System

Question 1

Mesentery

Answer 1

A fold of peritoneum that attaches the small intestine to the posterior abdominal wall

Question 2

Mesocolon

Answer 2

A fold of peritoneum that attaches the colon to the posterior abdominal wall

Question 3

Falciform ligament

Answer 3

A fold of peritoneum that attaches the liver to the anterior abdominal wall and diaphragm
Also separates the liver into two lobes

Question 4

Greater omentum

Answer 4

Also called the “fatty apron”

Hangs from the stomach and covers the transverse colon and the small intestine

Question 5

Lesser omentum

Answer 5

A fold of peritoneum that suspends the stomach and the duodenum from the liver

Question 6

Mucosa

Answer 6

Inner layer of alimentary canal
Protection
Secretion of enzymes, mucus, and hormones
Absorption of nutrients
Layer of smooth muscle cells produces movements of the mucosa
Pulls the mucous membrane of the small intestine into folds (called plicae circularis) increasing surface area

Question 7

Submucosa

Answer 7

Connective tissue that binds the mucosa to the muscularis

Contains blood and lymphatic vessels, lymph nodules, and nerve fibers

Question 8

Muscularis

Answer 8

Consists of an inner layer of circular smooth muscle and an outer layer of longitudinal smooth muscle
Mixes (segmentation) and propels (peristalsis) food and water along the digestive tract
The circular layer of smooth muscle form valves (sphincters) in specific areas of the tract

Question 9

Serosa

Answer 9

Visceral peritoneum
Consists of areolar connective tissue covered with simple squamous epithelium
Protection

Question 10

Amylase

Answer 10

Enzyme secreted by parotid glands
Produced in pancreas
Helps digest starch

Question 11

Cardiac sphincter

Answer 11

Lower esophageal sphincter

Controls passage from esophagus to stomach

Question 12

Oblique layer

Answer 12

Third layer of digestive tract
Only in stomach
Provides churning motion

Question 13

Pyloric sphincter

Answer 13

Valve between stomach and duodenum

Question 14

Mucous neck cells

Answer 14

Secrete mucous which is acidic and very different from the protective mucous secreted by the surface epithelium

Question 15

Chief cells

Answer 15

Secrete mainly the enzymes pepsinogen (breaks up proteins) and some lipase (breaks up fats)

Question 16

Parietal cells

Answer 16

Secrete hydrochloric acid (maintains the pH of stomach contents and kills bacteria) and intrinsic factor (necessary for the absorption of vitamin B12)

Question 17

Enteroendocrine cells

Answer 17

Release chemical messengers that stimulate the release of gastrin
Regulate gastric juice secretion

Question 18

Bile

Answer 18

From the liver, stored in the gallbladder

Helps digest fats

Question 19

Lipase

Answer 19

From the pancreas

Helps digest fats

Question 20

Proteases

Answer 20

From the pancreas

Help digest proteins

Question 21

Crypts of Lieberkuhn

Answer 21

Glands in small intestine

Screte enzymes that chemically digest proteins and carbohydrates

Question 22

Peyer’s Patches

Answer 22

Clumps of lymphoid follicles found in abundance toward the end of the small intestine

Question 23

Ileocecal valve

Answer 23

Connects the ileum to the first part of the large intestine

Prevents feces from reentering the small intestine

Question 24

Functions of the large intestine

Answer 24

Absorption of water and electrolytes
Synthesis of vitamin K and certain B vitamins by intestinal bacteria
Elimination of feces (defecation)

Question 25

Functions of the liver

Answer 25

Manufacture bile for the breakdown of lipids in the duodenum. This breakdown is necessary before lipase can finish the job.

Question 26

Acinar cells of the pancreas

Answer 26

Secrete digestive enzymes into tiny ducts, which eventually merge to form the main pancreatic duct

Question 27

Pancreatic ducts

Answer 27

Joins the common bile duct to form a single point of entry into the duodenum

Question 28

Pepsin and trypsin

Answer 28

Pepsin - in stomach
Trypsin - in small intestine
Break proteins into shorter chains (peptides)

Question 29

Pepsidase

Answer 29

Breaks peptides into amino acids

Question 30

Brush border enzymes

Answer 30

Break the nucleotides down to the component parts – pentose, phosphate, and nitrogenous bases

Question 31

Splanchnic circulation

Answer 31

Arteries branching off the abdominal aorta serving the digestive organs

Question 32

Peristalsis

Answer 32

Involuntary waves of contraction and relaxation that move substances through hollow body organs

Question 33

Segmentation

Answer 33

Movement of chyme backward and forward over the intestinal wall to allow maximum nutrient absorption

Question 34

Papillae

Answer 34

Small peg-like projections

Question 35

Mastication

Answer 35

Chewing