Oesophagus And Stomach Flashcards
What are 5 functions of the GIT
Ingestion
Digestion
Absorption
Elimination
Protection
What type of epithelium is mucosa made of
Stratified squamous epithelium
What is the function of mucosa
Provides protection from abrasive foods and liquids
What does the submucosal and mucosal glands do
Secrete protective/lubricating mucous
What are the 3 functions of the cardiac and pyloric glands
Primary mucus secreting
Cardiac glands have coiled ends
Pyloric glands are highly branched
What is the intrinsic innervation of the control of the GIT
Myenteric and submucosal plexuses
What are interstitial cells of cajal
Pacemakers for peristaltic action of the gut and sit in the myenteric and submucosal plexuses
How does the GIT communicate with the brain
Via nerve which function as the gut brain axis sensory neurons with cell bodies in dorsal root ganglia or in parasympathetic relay ganglia - there is no region in the brain exclusively dedicated to gut functions
What are the 2 intrinsic enteric nervous system controls
Myenteric (Auerbachs)
Meissners
What are the 2 extrinsic nervous systems controls
Parasympathetic
Sympathetic
What does the submucosal nerve plexus do
Regulates glandular and mucosal secretions
What does the myenteric plexus do
Controls gut wall contraction and gut motility
What does the parasympathetic control do
Enhances gut motility and secretion
What does the sympathetic control do
Inhibits gut motility and secretion
What are enterochromaffin like (ECL cells)
Distinctive type of neuroendocrine cell in the gastric mucosa underlying the epithelium
Synthesise and secrete histamine in response to stimulation by the hormone gastrin
What does cardia do
Mainly mucus secreting cells
What does fundus do
Acid producing parietal cells
Pepsin producing chief cells
What does pylorus do
Gastrin hormone production
What are the 3 main phases of stomach digestion
Cephalic
Gastric
Intestinal (Basal)
What is the stimulation for the cephalic phase
CNS responses to presentation of food enhances gastric gland secretion
What is the inhibition of the cephalic phase
Loss of appetite satiety/depression
What is the cephalic phase mediated by
The vagus nerve entirely reflex in origin
What happens in the gastric phase
Food enters the stomach stretch activate pH increase peptides produced increase gastric gland secretion
What 2 factors decrease gastrin secretion
If pH <2.0
Sympathetic response also decrease gastrin activity
What happens in the intestinal phase
Chyme produced after stomach digestion enters duodenum enteric mucosa secretes gastrin stimulates secretion by gastric glands
What 4 factors happen when the enterogastric reflex is triggered
Inhibits stimulation
Inhibits local reflexes
Controls gastric emptying
Stimulates sympathetic fibres to close pyloric sphincter
