Deck 1: Intake: Digestion, Absorption, Transport, and Excretion of Nutrients

Question 1

The sight or smell of food produces vagal stimulation of the parietal cells of the gastric mucosa, resulting in the increased production of what?

A)Motilin
B)Hydrochloric acid
C)Cholecystokinin
D)Secretin

Answer 1

B
Parasympathetic innervation that causes release of hydrochloric acid helps prepare the stomach for the potential of receiving food.After food chyme is passed into the small intestine from the stomach, secretin and cholecystokinin are secreted to stimulate pancreatic secretion of water and bicarbonate.They also signal gallbladder contractions and colonic motility, all resulting in reductions in stomach emptying and duodenal motility.Motilin is secreted from the duodenal mucosa during fasting to stimulate gastric emptying and intestinal motility.

Question 2

In what form is dietary fat absorbed from the lumen of the intestine?

A)Chylomicron
B)Micelle
C)Triglyceride
D)Lipoprotein

Answer 2

B
Fats must be emulsified into micelles so that they may cross the unstirred water layer that borders the brush-border membranes.These micelles leave monoglycerides and fatty acids at the brush border, where they are reabsorbed and reassembled as triglycerides.The triglycerides are packaged with cholesterol, fat-soluble vitamins, and phospholipids into chylomicrons, which pass into the lymphatic circulation.When these reach the liver, the chylomicron components are repackaged into low-density lipoproteins.

Question 3

By which transport mechanism are most vitamins absorbed from the small intestine into the blood?

A)Passive diffusion
B)Active diffusion
C)Facilitative diffusion
D)Passive osmosis

Answer 3

A
Passive diffusion is limited by the number of channels available for nutrients to randomly pass through.Facilitated diffusion requires the presence of carrier proteins, which may be limited by the health and nutritional status of the person.Active transport requires energy, which also may be limited by the person's health and nutritional status.Osmosis occurs in regard to concentration gradient and only involves the movement of water, not vitamins.

Question 4

How often do the cells lining the intestinal tract recycle?

A)Every 2 to 3 days
B)Every 3 to 5 days
C)Every 5 to 7 days
D)Every 10 to 14 days

Question 5

What happens to cellulose and lignin as they go through the GI tract?

A)They are converted into glucose before absorption.
B)They are converted into glucose and absorbed by active transport.
C)They are excreted in the feces unchanged.
D)They are excreted in the feces as glucose.

Question 6

Which of the following is formed by bacterial synthesis in the colon?

A)Vitamin K
B)Vitamin D
C)Vitamin B6
D)Niacin

Question 7

If a patient experiences malabsorption of fat resulting from an impaired ability to produce adequate bile salts for micelle formation, how may fat absorption be improved?

A)By increasing short-chain fatty acids in the diet
B)By increasing medium-chain fatty acids in the diet
C)By increasing long-chain fatty acids in the diet
D)By restricting dietary intake of cholesterol

Question 8

What are primarily absorbed by the large intestine?

A)Water and fats
B)Carbohydrates
C)Proteins
D)Water and electrolytes

Question 9

SGLT-1 is key to the small intestine's ability to absorb water because

A)it is an active transporter of sodium and glucose.
B)it blocks the transport of sodium.
C)it stimulates the body's thirst mechanism.
D)it changes the pH of the small intestine.

Question 10

What is the function of secretin?

A)Stimulation of gastric secretions and increased motility
B)Stimulation of gallbladder contraction and the release of bile
C)Stimulation of the pancreas to secrete water and bicarbonate
D)Stimulation of the parietal cells to secrete gastrin

Question 11

What effect may be achieved by eating a diet high in prebiotic carbohydrates?

A)Decreased SCFA production in the bowel
B)Increased growth of Lactobacillus spp.
C)Decreased absorption of bile salts
D)Increased absorption of cation minerals

Question 12

Pepsinogen is converted to pepsin when it comes in contact with

A)enterokinase.
B)trypsinogen.
C)hydrochloric acid.
D)peptidases.

Question 13

How long does it take for small intestine contents to reach the ileocecal valve?

A)18 to 72 hours
B)3 to 8 hours
C)1 to 2 hours
D)2 to 3 hours

Question 14

After surgical removal of a large portion of the small intestine, what functional complication is most likely to develop?

A)Changes in dietary habits
B)Impaired digestion
C)Loss of absorptive tissue
D)Elimination of dietary residue

Question 15

Which is the process by which minerals are absorbed when they are bound to an acid, organic acid, or amino acid?

A)Cotransportation
B)Carrier protein
C)Competitive inhibition
D)Chelation

Question 16

Which of the following is a list of enzymes released from the pancreas?

A)Insulin, trypsin, and secretin
B)Lactase, isomaltase, and dextrinase
C)Protease, pepsin, and gastrin
D)Trypsin, chymotrypsin, and carboxypeptidase

Question 17

Absorption occurs in the stomach for which of the following nutrients?

A)Vitamins
B)Carbohydrates
C)Minerals
D)Alcohol

Question 18

Which of the following is true of probiotics?

A)Probiotics are live microorganisms found in food.
B)Probiotics are nondigestible carbohydrates.
C)Probiotics act primarily on bacteria in the proximal small intestine.
D)Probiotics cannot be given as supplements because they readily die.