GI Motility Flashcards
Where are excitatory motor neurons and what are their NTs?
Excitatory motor neurons are found in the myenteric plexus
NTs: ACh, Substance P
Where are inhibitory motor neurons and what are their NTs?
Inhibitory motor neurons are found in the myenteric plexus
NTs: VIP, ATP, NO
Lower Esophageal Sphincter (LES) is innervated by?
Enteric Nervous System
Difference between internal and external anal sphincter?
Internal anal sphincter: smooth muscle
External anal sphincter: striated muscle
Medullary swallowing center receives input from?
Cortex and NTS
Medullary swallowing center projects to
DMX, N. XII and N. Ambiguus
Top 1/3 of esophagus is controlled by which nerves?
CN XII and N. Ambiguus
Lower 2/3 of esophagus is controlled by which nerve?
CN X
Which nerve is important for sensing food pressure and slow passage of food from proximal to distal stomach?
Vagus
ENS is also required, but ENS cannot respond to pressure alone
What is the gastrocolic reflex?
Gastric distension sends GVA from vagus to NTS
Preganglionic parasympathetics neurons to spinal cord
Cuases increased motility and mass movement in distal colon
What is the prominant motility pattern in the small intestines?
segementation
Where does peristaltic contraction begin?
In the antrum of the stomach.
Antrum is where pace maker cells reside
