Unit 3: The Human Body 1/2

Question 1

What are the two main groups of the digestive system?

Answer 1

1. The alimentary canal

2. Accessory digestive organs

Question 2

What components make up the alimentary canal?

Answer 2

Mouth, pharynx, esophagus, stomach, small intestine, large intestine

Question 3

What parts of the body make up the accessory digestive organs?

Answer 3

Teeth, tongue, gallbladder, liver, pancreas

Question 4

What are the two functions of the alimentary canal?

Answer 4

Digestion: breaking food up into smaller pieces
Absorption: moving digested fragments from the alimentary canal into blood

Question 5

What are the 6 essential activities of the digestive system?

Answer 5

1. Ingestion: taking food in
2. Propulsion: moving food through alimentary canal by swallowing and peristalsis
3. Mechanical digestion: chewing, segmentation
4. Chemical digestion: enzymes
5. Absorption: moving digested products from GI lumen into bloodstream (small intestine)
6. Defecation: elimination of waste

Question 6

How many layers are there in the alimentary canal and what are they

Answer 6

4 layers:

1. mucosa
2. submucosa
3. muscularis externa
4. serosa

Question 7

What are the 3 main functions of the first layer of the alimentary canal?

Answer 7

1. Secretion of mucus
2. Absorption of end products of digestion
3. Protection from infectious disease

Question 8

What are the three layers of the mucosa?

Answer 8

1. Epithelium
2. Lamina propria
3. Muscularis mucosae

Question 9

What does the epithelium layer of the mucosa do?

Answer 9

• mucus secretions protect digestive organs from digesting themselves and helps food along tract
• mucosa of the stomach and small intestine contain enzyme and hormone-secreting cells

Question 10

What does the lamina propria layer of the mucosa contain and function to do?

Answer 10

Consists of loose areolar and reticular connective tissue, plus lymph nodes.
Functions to nourish epithelium and absorb nutrients

Question 11

What does the muscluaris mucosae function to do?

Answer 11

Consists of smooth muscle that produces local movements of the mucosa.

Question 12

What does the submucosa consist of?

Answer 12

-dense connective tissue with elastic fibres, blood, lymphatic vessels, lymph nodes, and nerves

Question 13

What is the muscluaris externa responsible for?

Answer 13

• segmentation

- peristalsis

Question 14

What does the serosa consist of?

Answer 14

• epithelium

- connective tissue

Question 15

What are nerve plexuses?

Answer 15

a network of nerves that exit spinal cord and target a particular organ system

Question 16

What are the two nerve plexuses that are present in the digestive system and what do they do?

Answer 16

Submucosal nerve plexus regulates glands and smooth muscle in mucosa in small and large intestine.
Myentric nerve plexus is a major nerve supply that controls GI tract, mobility, and motility

Question 17

Which arteries provide blood to the small and large intestines?

Answer 17

Superior mesenteric for the small intestine

Inferior mesenteric for the large intestine

Question 18

What does blood flow in the digestive system help with?

Answer 18

• metabolic support to intestinal cells
• secretion of chemicals into GI lumen
• absorption of macro and micronutrients

Question 19

What’s the difference between the hepatic portal vein and the hepatic vein?

Answer 19

hepatic portal vein brings blood flow into the liver from the digestive organs, and the hepatic vein carries blood away from the liver into the vena cava