what is the oesophagus lined by
stratified squamous epithelium
what is the stomach lined by
tall columnar epithelium
what is an important feature of the stomach?(particularly cardia)
contains many mucous secreting cells to neutralise any acid that could go up the oesophagus (Which has no mucous cells)
role of fundus
store air
role of the body of the stomach
- mucous
- storage
- HCl production
- pepsinogen (digest food protein)
- intrinsic factor (absorb vitamin B12)
role of pyloric antrum
mix/grind
-gastrin: aid motility - mix fluids and digestive enzymes
role of pylorus
contains sphincter which controls chyme entering duodenum
how is food broken down
churning
pepsin - protein
HCl - allows action of pepsin and destruction of bacteria
what does the stomach absorb
- H2O, electrolytes
- alcohol (by stomach wall)
- asprin (cause bleeding in stomach)
what does the stomach secrete
gastrin (hormone - stimulate gastric acid secretion)
intrinsic factor
storage capacity of chyme at empty and full
75mls (empty), 2 or more litres (full
main functions of stomach
- temp store chyme
- secrete gastrin, intrinsic factor
- breakdown
- absorb
how long does food remain in the smonach
4 hrs
describe the arrangement of the gut wall (layers- from lumen)
- columnar epithelium
- lamina propria
- muscularis mucosa
- submucosal (meissner’s plexus) plexus
- submucosa
- inner circular
- outer longitudinal
- Myenteric (Auerbach’s) plexus
- adventitia or serosa
what is the gut wall smooth muscle controlled by (in terms of nervous system)
enteric NS
parasymp = stimulate contraction of smooth muscle
what does the vagus nerve do?
rhythmic peristaltic waves
control motility of oesophagus to the midgut (motor supply)
where does the foregut gets blood supply from
coeliac trunk - close to incisura angularis
