Biol 224 Exam 3- Digestive System

Front 1

Which type of epithelium lines the oral cavity?

Back 1

stratified squamous epithelium

Front 2

The digestion of which nutrient would be affected by damage to the parotid salivary glands?

Back 2

carbohydrates

Front 3

Which type of tooth is most useful for chopping off bits of relatively rigid foods?

Back 3

incisors

Front 4

What is unusual about the muscularis externa of the esophagus?

Back 4

-it contains skeletal muscle cells along most of its length
-it is surrounded by an adventitia rather than a serosa

Front 5

Where in the human body would you find the fauces?

Back 5

the fauces is the opening between the oral cavity and the pharynx

Front 6

What is ocurring when the soft palate and larynx elevate and the glottis closes?

Back 6

swallowing is ocurring

Front 7

How does a large meal affect the pH of blood leaving the stomach?

Back 7

stomach acid secreted for digestion takes hydrogen ions from the blood to be made, the blood leaving the stomach will have fewer and will have a higher pH

Front 8

When a person suffers from chronic gastric ulcers, the branches of the vagus nerve that serve the stomach are sometimes cut to provide relief. Why might this work?

Back 8

parasympathetic nerves can stimulate gastric secretions, even when food isn't present, cutting the nerve would prevent this and hopefully prevent more ulcers

Front 9

The enzymatic breakdown of large molecules into their basic building blocks is called

Back 9

chemical digestion

Front 10

The outer layer of the digestive tract is known as the

Back 10

serosa

Front 11

Double sheets of peritonium that provide support and stability for the organs of the peritoneal cavity are the

Back 11

mesentaries

Front 12

Most of the digestive tract is lined by ___ epithelium

Back 12

simple columnar

Front 13

Regional movements that occur in the small intestine and function to churn and fragment the digestive material are called

Back 13

segmentation

Front 14

What are the 6 steps involved in digestion?

Back 14

1-ingestion
2-mechanical processing
3-secretion
4-digestion
5-absorption
6-excretion

Front 15

Name and describe the layers of the digestive tract, proceeding from the innermost to the outermost layer.

Back 15

-mucosa, epithelial layer, digestion and absorption of nutrients
-submucosa, connective tissue layer conatins lymphatic and blood vessels and the submucosal nerve plexus
-muscularis externa, smooth muscle and the myenteric nerve plexus
-serosa, outermost layer, epithelium and connective tissue form visceral peritoneum or adventitia

Front 16

What three basic mechanisms regulate the activities of the digestive tract?

Back 16

neural mechanisms
hormonal mechanisms
local mechanisms

Front 17

What are the three phases of swallowing, and how are they controlled?

Back 17

buccal phase-voluntary
pharyngeal phase- involuntary
esophageal phase- involuntary

Front 18

How is the epithelium of the stomach protected from digestion?

Back 18

mucous secreted by epithelial cells, and nueral and hormonal control over the times and rates of acid secretion

Front 19

How do the three phases of gastric secretion promote and facilitate gastric control?

Back 19

-cephalic phase, sight or thought of food, directed by CNS, prepares stomach
-gastric phase, arrival of food in stomach, initiated by stomach distention, increase in pH, and presence of undigested materials
-intestinal phase, chyme enters intestine, controls rate of gastric emptying so that intestine can secrete, digest, and absorb efficiently

Front 20

After a heavy meal, blood pH increases, especially in veins coming from the stomach. Why?

Back 20

bicarbonate ions pass from parietal cells into the blood

Front 21

What component of food would increase the number of chylomicrons in the lacteals?

Back 21

A meal high in fat would increase chlyomicrons because they are fat-protein packages.

Front 22

The absorption of which vitamin would be impaired by the removal of the stomach?

Back 22

vitamin B12, this vitamin requires intrinsic factor for absorption which is produced by the parietal cells of the stomach

Front 23

Why is it that diarrhea is potentially life-threatening, but constipation is not?

Back 23

the loss of fluid and electrolytes can cause dehydration and even death, constipation doesn't cause such severe problems because the excess waste can eventually be taken care of by the kidneys

Front 24

A branch of the portal vein, hepatic artery, and tributary of the bile duct form the

Back 24

portal areas

Front 25

The major functions of the large intestine are

Back 25

-reabsorption of water and compaction of feces
-absorption of vitamins liberated by bacterial action
-storage of fecal material prior to defacation

Front 26

Three vitamins generated by bacteria in the colon are

Back 26

vitamin K, biotin, pantothenic acid, vitamin B5

Front 27

What are the three primary functions of the large intestine?

Back 27

1-resorption of water and compaction of the intestinal contents into feces
2-absorption of important vitamins liberated by bacterial action
3-storage of fecal material prior to defacation

Front 28

What two positive feedback loops are involved in the defacation reflex?

Back 28

1-stretch receptors in the rectal walls promote a series of rectal contractions in the colon and rectum, moving feces towards the anus
2- the sacral parasympathetic system innervated by stretch receptors stimulates peristalsis via motor commands distributed by the pelvic nerves

Front 29

How is the small intestine adapted for the absorption of nutrients?

Back 29

inreased surface area
-walls folded into plicae
-villi
-microvilli
rich supply of blood vessels and lymphatic vessels to transport nutrients that are absorbed

Front 30

How does a meal that is high in fat affect the level of cholecystokinin (CCK) in the blood?

Back 30

it increases it

Front 31

How would the pH of the intestinal contents be affected if the small intestine did not produce secretin?

Back 31

the pH would be lower because the pancreas would have less stimulation to produce and secrete buffers

Front 32

The digestion of which nutrient would be most impaired by damage to the exocrine pancreas?

Back 32

lipid digestion, the pancreas is the primary source of lipases, for carbs there would still be enzymes from saliva and small intestine and protein enzymes from stomach and small intestine

Front 33

What are the primary functions of the pancreas, liver, and gall bladder in digestion?

Back 33

pancreas- digestive enzymes and buffers
liver and gallbladder- bile for digestion and absorption of lipids
liver- metabolic and hematological regulation, bile production, primary organ of blood content regulation