L49: Alimentary System Controls Flashcards
What control is the alimentary system under?
- Nervous;
- Hormones.
What type of nervous control is the alimentary system under?
- Somatic, voluntary;
- Autonomic, involuntary.
What are the two autonomic nervous systems?
- Sympathetic: fight or flight;
- Parasympathetic: rest and digest.
What hormones control the alimentary system?
- Cholecystokinin (CCK) ‘bile-sac-mover’;
- Gastrin (G-cells);
- Gastric inhibitory peptide (GIP);
- Secretin.
What does the release of CCK do?
Contracts gall bladder (bile)
What does the release of gastrin do?
- Activates parietal cells (HCl);
- Aids gastric motility.
What does the release of GIP do?
- Induce insulin secretion by the pancreas;
- Also reduce the secretion of stomach acid and motility.
What does the release of secretin do?
- Stimulate secretion from liver and pancreas;
- Reduce acid production by parietal cells and increase bicarbonate production by pancreas.
Which part of the alimentary system is under autonomic nervous control?
Middle - lower oesophagus, stomach, intestines
Which part of the alimentary system is under hormonal control?
Stomach and small intestine
Which cranial nerves control saliva secretion?
7, 9 and 1 (minor-olfaction)
Which cranial nerve detects the load on PDL from chewing?
5
Which cranial nerve innervates the oesophagus?
10
What are the 3 major phases of digestion?
- Cephalic (before food enters);
- Gastric (swallowing of food);
- Intestinal (chyme entering duodenum).
At what point is a bolus of food called chyme?
From stomach > duodenum, through pyloric sphincter i.e. once food bolus has been mixed with gastric juices and is partially digested
