Gastrointestinal System

Question 1

What are the functions of the digestive tract?

Answer 1

• Transport
• Digest intake
• Absorb nutrients
• Excretion

Question 2

What is the general structure of the digestive tract?

Answer 2

• Mucosa (inner lining)
• Submucosa (Meissner’s Plexus)
• Muscle (Auerbach/Myenteric Plexus)
• Serosa

Question 3

What is the Meissner’s Plexus made up of?

Answer 3

Blood vessels
Glands
Nerve tissue

Question 4

What is the nerve layer in the muscle of the digestive tract?

Answer 4

Auerbach/Myenteric Plexus

Question 5

What is the type of nervous system in the digestive tract?

Answer 5

Enteric nervous system

Question 6

What are the THREE phases of swallowing?

Answer 6

1. Oral (voluntary)
2. Pharyngeal (reflex)
3. Oesophageal (reflex)

Question 7

How long is the oesophagus and what type of cells does it have?

Answer 7

25cm long with squamous cells

Question 8

What is Peristalsis?

Answer 8

Wave of muscle contraction

Question 9

What are the top, middle and bottom parts of the stomach?

Answer 9

Top: Fundus
Middle: Body
Bottom: Antrum

Question 10

What are the FIVE cell types in the stomach?

Answer 10

1. Goblet
2. Parietal
3. ECL
4. Chief cells
5. Hormone secreting

Question 11

Name the Gastric Acid Secretagogues

Answer 11

• Histamine
• Acetylcholine
• Gastrin

Question 12

How long is the small intestine and what are the THREE parts of it?

Answer 12

5m long
Duodenum (12in)
Jejunum
Ileum

Question 13

What is the structure of the mucosa in the small intestine?

Answer 13

Folded in microvilli

Question 14

What are interstitial cells of Cajal?

Answer 14

Pacemaker cells that moves chyme towards the colon in peristalsis

Question 15

Where is bile stored and where does it empty into?

Answer 15

Stored in the gallbladder
Emptied into the duodenum

Question 16

Are digestion and absorption regulated?

Answer 16

No
Motility and secretions are by hormones and neural mechanisms

Question 17

Name some glands in intestinal mucosa?

Answer 17

• Paracrine
• Autocrine
• Endocrine

Question 18

What does Meissner’s Plexus control?

Answer 18

Secretion

Question 19

What does Auerbach/Myenteric Plexus control?

Answer 19

Muscle layers

Question 20

What does Parasympathetic nerves do to digestive activity?

Answer 20

Increases digestive activity

Question 21

What are the THREE phases in the regulation of gastric function (acid secretion)?

Answer 21

1. Cephalic
2. Gastric
3. Intestinal

Question 22

What stimulates the CEPHALIC phase release?

Answer 22

Sight
Smell
Food taste
Reflex

Question 23

How is the CEPHALIC phase mediated?

Answer 23

By vagus stimulating parietal cells

Question 24

What stimulates GASTRIC phase release?

Answer 24

Distension of stomach
Presence of food

Question 25

How does GASTRIC release phase regulate itself?

Answer 25

Self regulation by negative feedback

Question 26

What stimulates INTESTINAL phase inhibition?

Answer 26

Chyme in duodenum

Question 27

What does the inhibition of gastric acid release?

Answer 27

Secretin

Question 28

Name TWO proteins that inhibit parietal cells

Answer 28

1. CCK 2. GIP

Question 29

How are intestinal functions regulated?

Answer 29

Neural regulation by enteric nervous system

Question 30

What are the THREE reflexes linked with intestine function regulation?

Answer 30

1. Gastroileal 2. Illeogastric 3. Intestino-intestinal

Question 31

What proteins increase pancreatic and liver bile secretions?

Answer 31

CCK and Secretin

Question 32

Where does digestion begin?

Answer 32

Mouth

Question 33

What is the function of pancreatic amylase?

Answer 33

Digests carbohydrates in duodenum

Question 34

Name some intestinal enzymes

Answer 34

Maltase Sucrase Lactase

Question 35

What are the only digestible sugars?

Answer 35

Glucose Galactose Fructose

Question 36

What is the function of pepsin in the stomach?

Answer 36

Convert proteins into short chain amino acids for absorption

Question 37

What is the function of bile salts?

Answer 37

Emulsify droplets of triglycerides

Question 38

Where do enzymes from the pancreas attach to bile?

Answer 38

To the head of bile which is fat soluble