Digestive System Part 1

Question 1

What are the functions of the Digestive System

Answer 1

• Take in food
• break down foodstuffs
• absorb nutrients into bloodstream
• rid body of indigestible materials

Question 2

What are the 6 major processes of the digestive system? Briefly describe each.

Answer 2

1. Ingestion
   - mastication & swallowing
2. Propulsion
   - peristalsis (alt. waves of contraction and relaxation)
3. Mechanical Breakdown
   - Segmentation (localized contractions; front and back)
4. Digestion
   - enzymes breakdown complex food molecules into chemical building blocks
5. Absorption
   - absorb nutrients from lumen of GI tract into the bloodstream
6. Defecation
   - elimination of indigestible materials through anus in the form of feces

Question 3

What organs comprise the GI tract/alimentary canal?

Answer 3

mouth
pharynx
esophagus
stomach
small intestine
large intestine
anus

Question 4

What organs comprise the accessory organs?

Answer 4

Teeth
Tongue
Salivary Glands
- Parotid
- Sublingual
- Submandibular

Question 5

What are the four tunics/layers of the alimentary canal?
Innermost to external most.

Answer 5

1. Mucosa
2. Submucosa
3. Muscularis Externa
4. Serosa/ Adventitia

Question 6

What is the peritoneum and its two types?

Answer 6

serous membranes
visceral - surrounds organs
parietal - lines body cavity

Question 7

What does the mesentery do and what’re its two types?

Answer 7

Holds organs in place, site of fat storage, route for circulatory vessels
Greater Omentum: “fatty apron”
Lesser Omentum: attaches to lesser curvature of stomach and liver

Question 8

Define intraperitoneal, retroperitoneal, and secondarily retroperitoneal, and provide visceral
examples for each.

Answer 8

Intraperitoneal: within peritoneum
- Ex: stomach, small intestine
Retroperitoneal: outside peritoneum
- Ex: Kidneys, esophagus, anus
Secondarily retroperitoneal
- Ex: pancreas and parts of large intestine

Question 9

Briefly describe the histology and functions of the Mucosa.

Answer 9

• secretes mucus
• absorbs end products of digestion
• protects against disease
  3 sublayers
• Epithelium
• Lamina propria
• Muscularis mucosae

Question 10

Briefly describe the histology and functions of the Submucosa.

Answer 10

• areolar CT
• abundant in elastic tissue (help regain shape)

Question 11

Briefly describe the histology and functions of the Muscularis Externa.

Answer 11

• smooth muscles (longitudinal & circular)
• segmentation and peristalsis

Question 12

Briefly describe the histology and functions of the Serosa/Adventitia.

Answer 12

• visceral peritoneum
• Adventitia when esophagus/anus