Topic 15 - Digestive system (B)

Question 1

Digestive system overview:

• includes
  
  • 1) Gastrointestinal (GI) tract
    
    • tube to mouth of anus
  • 2) Accessory organs
    
    • teeth, tongue, salivary glands
    • pancreas
    • liver, gall bladder

Question 2

food into oral cavity

Answer 2

ingestion

Question 3

• large molecules broken down into smaller molecules
• 2 types:
  
  • mechanical
  • chemical

Question 4

end products of digestion enter blood or lymph

Answer 4

absorption

Question 5

elimination of undigested material

Answer 5

defecation

Question 6

what are the 4 basic layers of the gastrointestinal tract?

Answer 6

1. Mucosa
2. Submucosa
3. Muscularis externa
4. Serosa (or adventitia)

Question 7

Gastrointestinal tract: 4 basic layers

Mucosa

• how many layers? name them

Answer 7

• 3 layers
  
  • epithelium with numerous goblet cells
  • lamina propria = areolar CT
  • muscularis mucosa

Question 8

Gastrointestinal tract

Mucosa

3 layers: Epithelium with numerous goblet cells

Answer 8

• stratified squamous: mouth pharynx, esophagus, anal canal
• simple columnar: stomach, small + large intestines, rectum

Question 9

Gastrointestinal tract

Mucosa

3 layers: Lamina propria = areolar CT

Answer 9

• contains blood, lymph vessels, lymph nodules/tissues (immune)

Question 10

gastrointestinal tract

Mucosa

3 layers: muscularis mucosa

Answer 10

smooth muscle - allows movement of mucosa

Question 11

Gastrointestinal tract

Submucosa

Answer 11

• areolar CT
• contains: blood + lymphatic vessels, submucosal nerve plexus

Question 12

Gastrointestinal tract

Muscularis externa

Answer 12

• smooth muscle
• inner circular layer
• outer longitudinal layer
• myenteric nerve plexus between layers
• contractions cause motility (mixing + movement)

Question 13

Gastrointestinal tract

Serosa (or adventitia)

Answer 13

cavity = lumen