GI Motility I

Question 1

What receptors are founds at the (pre/post) ganglionic synapse? What receptors are found at the effector organ? (for SM - autonomic)

Answer 1

S: Nicotinic, Adrenergic
PS: Nicotinic, Muscarinic

Question 2

Nicotinic, Muscarinic are blocked respectively by _____, _____

Answer 2

N: Curare
M: Atropine

Question 3

What are the three phases of swallowing

Answer 3

• Oral/Voluntary – receptor stimulation
• Pharyngeal – initiation of peristalsis
• Esophageal – One or two peristaltic waves (food reaches stomach)

Question 4

Explain Secondary Peristaltic Wave

Answer 4

Food moving slower that primary wave. local reflex response (stretch receptors) initiate a secondary response.

Question 5

Name the Excitatory (contraction) and Inhibitory (relaxation) NT?

Answer 5

Excitatory (Cont): Ach Sub P

Inhibitory (Relax): NO, VIP

Question 6

Explain Law of intestines (short/local response)

Answer 6

Sensory receptors in SM, send signal to Myenteric plexus. Inhibitory interneurons signal inhibitory motor neurons which activate distal SM by NO, VIP; excitatory interneurons signal excitatory motor neurons which activate proximal SM with Ach, Sub P) –> Forward Pushing

Question 7

Acalashia 
Diffuse Esophageal Spasm
Scleroderma
GERD
Hiatus Hernia

Answer 7

Acalasia - NG, peristalsis/LED problems
Diffuse Esophageal Spasm - NG/peristalsis prob
Scleroderma - replaced SM with fibrous tissue
GERD - Gastroesophageal reflux
Hiatus Hernia - prot. stomach over diaphram