A&P - Chapter 40 (Part 2)

Question 1

What is emptying the stomach after a big meal controlled by? (2)

Answer 1

1. Hormonal mechanisms

2. Nervous mechanisms

Question 2

Hormonal mechanisms

Answer 2

The presence of fat in the duodenum stimulates a hormone that slows down the passage of chyme into the duodenum

Question 3

Nervous mechanisms

Answer 3

Presence of acid and distention picked up by receptors in duodenal mucosa, then the impulses travel through vagus nerve which inhibits gastric peristalsis

Question 4

What is included in intestinal motility?

Answer 4

1. Peristalsis

2. Segmentation

Question 5

Segmentation of the intestinal motility (2)

Answer 5

1. Occurs in the duodenum and the first part of the jejunum

2. Mixes chyme with digestive juices from the pancreas, liver and intestinal mucosa

Question 6

Peristalsis of the intestinal motility

Answer 6

Moves chyme through rest of small intestine and into the large intestine

Question 7

How long does it take for chyme to travel through the length of the small intestines?

Answer 7

5 hours

Question 8

What is peristalsis regulated by?

Answer 8

1. Stretch reflexes
2. The hormone cholecystokinin
   - CCK

Question 9

What do chemical changes in digestion result from?

Answer 9

Hydrolysis

Question 10

Where do digestive enzymes function in?

Answer 10

In the lumen of the digestive tract

Question 11

Hydrolases

Answer 11

Breakdown food molecules using water

- all digestive enzymes

Question 12

Are enzymes specific?

Answer 12

Yes

- lock and key

Question 13

What do enzymes require for optimal function?

Answer 13

1. Specific pH

2. Temperature

Question 14

Do digestive enzymes go in reverse?

Answer 14

No

Question 15

Why are digestive enzymes continually synthesized?

Answer 15

Because they are continually destroyed or eliminated from body
- even though they are not used up in the reaction they catalyze/assist

Question 16

What are most digestive enzymes synthesized and secreted as?

Answer 16

Inactive proenzymes

Question 17

What kind of compound are carbohydrates?

Answer 17

Saccharide

Question 18

Where do carbohydrates begin to digest?

Answer 18

In the mouth

Question 19

What enzyme breaks down carbohydrates?

Answer 19

Salivary amylase

Question 20

Does any digestion of carbohydrates occur in the stomach?

Answer 20

No

Question 21

Where does most of the digestion of carbohydrates occur?

Answer 21

Small intestines

Question 22

What are polysaccharides hydrolyzed by? What does it form?

Answer 22

1. Amylase

2. Forms disaccharides

Question 23

What is the final step of carbohydrate digestion?

Answer 23

Going from disaccharides to monosaccharides

Question 24

What is maltose made up of? (2)

Answer 24

1. Glucose

2. Glucose

Question 25

What is sucrose made up of? (2)

Answer 25

1. Glucose

2. Fructose

Question 26

What is lactose made up of? (2)

Answer 26

1. Glucose

2. Galactose

Question 27

What do proteins break down into?

Answer 27

Amino acids

Question 28

Where does protein digestion begin?

Answer 28

In the stomach

Question 29

What are the main proteases of protein digestion? (3)

Answer 29

1. Pepsin
2. Trypsin and chymotrypsin
3. Peptidases

Question 30

Pepsin

Answer 30

Gastric juice, partially digests proteins

Question 31

Trypsin and chymotrypsin

Answer 31

Pancreatic enzymes, continue digestion of proteins

Question 32

Peptidases

Answer 32

Intestinal enzymes, complete digestion of protein to amino acids