Lecture 3-Physiology Flashcards
Which spinal divisions are part of the sympathetic innervation to the GI tract?
T5-L3
Which spinal divisions form the greater splanchnic nerve?
T5-9
Which spinal divisions form the lesser splanchnic nerve?
T10-11
Which spinal division forms the least splanchnic nerve?
T12
True or false: sympathetic innervation in the GI tract mainly innervates blood vessels
TRUE
Which nerve provides the major parasympathetic innervation to the GI tract?
Vagus nerve
True or false: left vagus nerve becomes posterior and right vagus nerve becomes anterior as the foregut rotates
FALSE - other way round
Which part of the GI tract do the parasympathetic fibres innervate?
Smooth muscle, endocrine and secretory parts
True or false: the enteric nervous system can operate independently of the ANS
TRUE
What are the two main plexuses of the enteric nervous system?
1) submucosal (Meissner’s)
2) myenteric (Auerbach’s)
Give an example of a paracrine peptide and state where it’s found and what it does
- Somatostatin
- D cells in antrum of stomach and pancreas
- Stimulated by H+ in stomach and inhibits G cells and histamine release
Give an example of a neurocrine peptide, where it is found and what it does
- Gastrin releasing peptide (GRP)
- Released by vagus nerve
- Increases release of gastrin from G cells
What are the two families of GI hormones?
Gastrin family
Secretin family
What are the two hormones in the GI family?
Gastrin
Cholecystokinin
What does gastrin bind to and what does it do?
CCK receptor
Increases gastric acid secretion