Control of gut Flashcards
What are the methods of control of the gut?
Neural control
Hormonal control
Paracrine control
What is the neural control of the gut?
Autonomic nervous system control
Enteric nervous system control
What overall effect does sympathetic innervation have on the gut?
Inhibits the functions of the GI tract
How does the sympathetic nervous system inhibit the functions of the gut?
Causes vasoconstriction of blood vessels, reducing blood flow to the gut
Decreases secretions from glands
What neurotransmitters do the parasympathetic post-ganglionic nerve fibres release?
Acetylcholine
Gastrin releasing peptide
Vaso inhibitory peptide
What overall effect does parasympathetic innervation have on the gut?
Stimulates the functions of the GI tract
How does the parasympathetic nervous system stimulate the functions of the gut?
Increases motility of the gut
Increases secretions from glands
What are the parts of the enteric nervous system?
Submucosal plexus
Myenteric plexus
Where is the submucosal plexus located?
In the submucosa
Where is the myenteric plexus located?
Between the inner circulator layer and the outer longitdinal layer of the muscularis externae
How far along the GI tract does the enteric nervous system extend?
Along the whole GI tract
from the oeophagus to anus
What does the submucosal plexus control?
Secretions from epithelial cels
Local blood flow
What does the myenteric plexus control?
Motility
What is the relation between the autonomic and enteric nervous systems controlling the gut?
They are connected to each other
communicate with each other
What are the two families of hormones in the GI tract? What are the hormones in each family?
Gastrin
- gastrin
- cholecystokinin
Secretin
- secretin
- gastric inhibitory peptide
