module 13 digestion and motility

Question 1

oral cavity digestion

Answer 1

mechanical: chewing and swallowing
chemical: carbs

Question 2

stomach digestion

Answer 2

mechanical: peristaltic mixing and propulsion
Chemical: proteins

Question 3

Small intestine digestion

Answer 3

mechanical: mixing and propulsion, primarily by segmentation
Chemical: carbs, lipids, proteins, nucleic acids

Question 4

Large intestine digestion

Answer 4

mechanical: segmental mixing, mass movement for propulsion

no chemical digestion except by bacteria

Question 5

Gut wall

Answer 5

endocrine cells
exocrine cells
mucous cells 
ducts from external exocrine glands 
-liver, pancreas, salivary

Question 6

peristalsis

Answer 6

allows forward propulsion

smooth muscles cells of GI: circular muscle

Question 7

segmental contractions

Answer 7

allow mixing

Question 8

contractions occur in response to

Answer 8

spike potentials

• tonic
• rhythmic
• mixing
• propulsion

Question 9

tonic contractions

Answer 9

Electrical
continuous, instigated by pacemaker cells
- intensity varies with frequency of spike potentials
- determines pressure in segment

Question 10

rhythmic contractions

Answer 10

Electrical

Slow-wave dependent contractions are responsible for mixing and peristaltic movement

Question 11

segmental (mixing) contractions

Answer 11

muscular

to breakdown and absorb

Question 12

propulsion

Answer 12

muscular
moving forward
rate dependent on organs of tract
- slow form stomach to large intestine to ensure digestion and absorption

Question 13

regulation of peristalsis

Answer 13

distention
Cholinergic interneurons
- excitatory motor neuron proximal to bolus
- inhibitory motor neuron distal to bolus
-> proximal contraction and distal relaxation to move bolus forward