Motility Flashcards
What are the types of muscle contraction in the gut?
Phasic
Tonic
What is meant by phasic muscle contraction in the gut?
Short periods of both muscle contracton and relaxation
What is meant by tonic muscle contractions in the gut?
Maintained muscle contractions
Where do tonic muscle contractions occur in the gut?
Sphincters
What muscle is responsible for movements of the gut?
Muscularis externae
What are some examples of phasic muscle contractions in the gut?
Peristalsis
Segmentation
Mass movements
How does peristalsis work?
Contraction of muscle proximal to contents
relaxation of muscle distal to contents
What is the purpose of peristalsis?
To move contents along the gut
at an appropriate rate for digestion and absorption
What is the control of peristalsis?
Neural control
- myenteric plexus
- parasympathetic nervous system
How does the myenteric plexus control peristalsis?
Stimulates it
How does the parasympathetic nervous system control peristalsis?
Stimulates it
What stimulates the myenteric plexus to stimulate peristalsis?
Distension of gut tube
How does segementation work?
Contraction both proximal and distal to gut contents
splits the contents
moves them forwards and backwards
What is the purpose of segmentation?
Mix gut contents
What is mass movements?
Rapid movement of large amounts of contents along the gut
