Gi Physiology Flashcards
what epithelium is the oesophagus
stratified squaous NK epithelium until diaphragm
below diaphragm = simple columnar
What is the muscles like in the oesophagus
inner circualr outer longittidinal Proximal 1/3 = skeletal middle 1/3 = mixed distal 1/3 = smooth
Describe the nerve supply to oesophageal muscle
inner circular = meissners plexus
Outer circular = auerbachs plexus
What cells are found in the cardiac tegion of the stomach
cardiac glands - goblet cells
What cells are found in the body and fundus of the stomach
goblet cells parietal cells chief cells D cells G cells
Which cells release somatosatn and what is somatostatins function
D cells release somatostain
it inhibits gastric acid secretions in response to acid in the stomach
what is gastrins role?
promtes secretion of gastric acid and histamine
histamine then positivey feedback to promote more acids secretion from parietal cells
What inhibits Gastrin
HCl production
What are the 3 phases of gastric secretion?
Cephalic
Gastric
Intestinal
Describe the Cephalic phase of secretion
Triggered by sight/smell/sounds
increases in PS stimulation to stomach enteric nervous sytem
Define Enteric Nervous System?
The enteric nervous system (ENS) is the intrinsic nervous system of the gastrointestinal trac
Where does histamine act and what does it do?
Directly on Parietal cells
increases release of gastric acid
Where are Pariteal cells located
what do they produce
HCL
Intrinsic Factor
Located in body and fundus
Where is B12 absorbed?
Proximal Ileum and requires intrinsic factor to be absorbed which is produced by Parietal Cells
Where is folate reabsorbed
proximal jejenum and Ileum