A&P - Chapter 40 (Part 1)

Question 1

What are the primary functions of the digestive system suppose to do?

Answer 1

Bring essential nutrients into the body and make them available to all cells

Question 2

What are the steps in digestion? (7)

Answer 2

1. Ingestion
2. Digestion
   - mechanical and chemical
3. Motility of the GI wall
4. Secretion
5. Absorption
6. Elimination
7. Regulation

Question 3

Ingestion

Answer 3

Food is taken into the body

- through the mouth

Question 4

Digestion

Answer 4

Complex nutrients (eg. carbs, fats, proteins) are broken down into simple nutrients (e.g. monosaccharides, amino acids, fatty acids, etc)

Question 5

Motility of the GI wall

Answer 5

Mechanical breakdown and movement of food through GI tract

Question 6

Secretion

Answer 6

Digestive enzymes

- chemical digestion

Question 7

Absorption

Answer 7

Movement of nutrients

- GI mucosa –> internal environment

Question 8

Elimination

Answer 8

Excretion of unabsorbed material

Question 9

Regulation

Answer 9

Coordination of all digestive system functions

Question 10

What are the 2 types of digestion?

Answer 10

1. Mechanical

2. Chemical

Question 11

Mechanical digestion

Answer 11

Physically breaks large chunks of food into smaller bits and pieces

Question 12

Chemical digestion

Answer 12

Breaks molecules apart and chemically changes the food

- e.g. protein break down into amino acids

Question 13

What happens during mechanical digestion?

Answer 13

Churns contents of the GI lumen to mix with digestive juices and ensure contact with the surface of the intestinal mucosa, facilitating absorption

Question 14

What does mechanical digestion propel?

Answer 14

Food along the alimentary tract, eliminating digestive waste from the body

Question 15

What does mechanical digestion involve? (5)

Answer 15

1. Mastication
   - chewing
2. Deglutition
   - swallowing
3. Peristalsis and segmentation
4. Regulation of motility
5. Intestinal Motility

Question 16

Mastication

Answer 16

Reduces size of food particles and mixes food with saliva to prepare it for deglutition
- chewing

Question 17

What is another word for swallowing?

Answer 17

Deglutition

Question 18

What are the 3 stages of deglutition?

Answer 18

1. Oral stage
2. Pharyngeal stage
3. Esophageal stage

Question 19

What kind of control is the oral stage of swallowing?

Answer 19

Voluntary

Question 20

Oropharynx

Answer 20

Mouth

Question 21

Oral stage

Answer 21

Food bolus is formed and is pushed against the palate by the tongue, then moved back into the oropharynx

Question 22

What kind of control is the pharyngeal stage of swallowing?

Answer 22

Involuntary

Question 23

What does the pharyngeal stage of swallowing require?

Answer 23

Blockage of mouth

- nasopharynx and larynx

Question 24

How is the pharyngeal stage of swallowing accomplished? (2)

Answer 24

1. Contraction

2. Gravity

Question 25

What kind of control is the esophageal stage of swallowing?

Answer 25

Involuntary

Question 26

How is the esophageal stage of swallowing accomplished? (2)

Answer 26

1. Contraction

2. Gravity

Question 27

What are two main types of motility produced by smooth muscle of the GI tract? (2)

Answer 27

1. Peristalsis

2. Segmentation

Question 28

Peristalsis

Answer 28

Wave-like ripple of the muscle layer of a hollow organ that moves matter forward in the GI tract

Question 29

What is peristalsis triggered by?

Answer 29

The presence of food

Question 30

Segmentation

Answer 30

A forward-and-backward mixing movement within a single segment of the GI tract

Question 31

What does segmentation help with?

Answer 31

The breakdown food, by mixing food with digestive juices and bringing it in contact with the intestinal mucosa where absorption takes place

Question 32

Gastric motility

Answer 32

Food in stomach is churned and mixed with gastric juices to form chyme
- via peristaltic contractions called propulsion and retropropulsion

Question 33

How often does chyme exits the stomach?

Answer 33

Every 20 secs