Digestive System

Question 1

Polysaccharide

Answer 1

A polymer of thousands of simple sugars formed by de-
hydration synthesis. Chemically digested by amylases in saliva and pancreatic juice.

Question 2

Glycogen

Answer 2

The form in which the liver and muscles store glucose as a polysaccharide.

Question 3

polypeptide

Answer 3

A polymer (chain) of many amino acids linked together
by peptide bonds. Chemically digested by pepsin in the stomach and various pancreatic enzymes

Question 4

lipid

Answer 4

Nonpolar molecule consisting of a glycerol and two or three fatty acid chains. Includes fats, oils, and cholesterol. Emulsified by bile, chemically digested by pancreatic lipase.

Question 5

saliva

Answer 5

Contains mucus and various enzymes. Mucus protects mouth & coats food.

Question 6

gastric juice

Answer 6

Mixture produced in stomach consisting of hydrochloric
acid, pepsinogen (inactive), pepsin (activated by HCl), and
intrinsic factor (aids in B-12 absorption).

Question 7

bile

Answer 7

Mechanically digests lipids (emulsification). Produced in
liver, stored in gall bladder, secreted into small intestine,
neutralizes HCl from stomach.

Question 8

gastrointestinal tract

Answer 8

One-way tube composed of smooth muscle. Organs through which food pass, as opposed to accessory organs.

Question 9

peristalsis

Answer 9

Process of wave-like muscle contractions of the GI tract
that moves food along. Stretching of smooth muscle (due to volume of food) increases excitability.

Question 10

small intestine

Answer 10

Responsible for most chemical digestion and absorption of nutrients. Pancreatic enzymes and brush border enzymes chemically digest all nutrients. Villi absorb end products.

Question 11

Duodenum

Answer 11

The first part of the small intestine immediately beyond
the stomach, leading to the jejunum. Bile and pancreatic
juices are secreted into the intestinal lumen here.

Question 12

brush border enzymes

Answer 12

Integral membrane proteins on the surface of the intestinal
microvilli. Complete chemical digestion of nutrients. Some
convert inactive pancreatic enzymes to active form.

Question 13

large intestine

Answer 13

About 6 feet long and is composed of the cecum, colon,
rectum and anus. Absorbs water and forms feces.

Question 14

GI hormones

Answer 14

Produced by digestive tract, act first locally, then generally.
Influence appetite, GI motility, enzyme activity, and electrolyte levels.

Question 15

Autonomic Control of GI tract

Answer 15

Sympathetic NS: slows down GI tract, Parasympathetic NS: speeds up GI tract

Question 16

villi

Answer 16

Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption. Tissue level of organization. Capillaries and lacteals located within.

Question 17

lacteal

Answer 17

Lymph tubule located in the villus that absorbs fatty acids.

Question 18

microvilli

Answer 18

Slender extensions of the small intestinal cells’ plasma membranes that increase their absorptive surface area. Contain brush border enzymes.

Question 19

ulcer

Answer 19

Breakdown of mucus layer protecting the stomach or duodenal wall from hydrochloric acid. Risk factors include:
increased alcohol or salt intake, stress, certain bacteria.

Question 20

smooth muscle tissue

Answer 20

Involuntary muscle tissue found in inner organs walls like
bladder, intestines, stomach, blood vessels, etc.