B15 Flashcards
What is achalasia?
Failure of smooth muscle of lower oesophageal sphincter to contract which results in reduced peristalsis in response to food bolus
What is the control of the internal anal sphincter?
Parasympathetic system
What is the control of the external anal sphincter?
Somatic system
Which cranial nerves innervate saliva?
Facial and glossopharyngeal
What is the role of somatostatin?
Released by delta cells to Inhibits pancreatic secretions.
OPPOSES CHOLECYSTOKININ AND SECRETIN
How does cystic fibrosis affect pancreatic exocrine secretion?
Low Cl- secretion so there is lower exchange with HCO3-.
Which cells are responsible for reducing the acidity of the small intestine?
S cells which produce secretin in response to low small intestine pH. Secretin will stimulate bicarbonate secretion from pancreas.
How does gastrin affect bile acid secretion?
Indirectly increases it, due to greater HCL stimulating duodenal cells to increase pancreatic secretions.
Which branch of the nervous system increases bile acid secretion?
Parasymapthetic
What is the effect of sympathetic nervous system on bile acid secretion?
Decreased
What is the consequence of reduced bile acid absorption in terminal ileum?
High amounts of bile acid will enter the large intestine and stimulate water loss from lumen, causing diarrhoea.
What cause of jaundice results in increase in unconjugated bilirubin?
Gilbert syndrome
—> Hepatitis will not affect due to
What causes rise in conjugated bilirubin?
Hepatitis
Liver cirrhosis
Gall bladder or pancreatic pathology
What are the features of post-hepatic jaundice?
Dark urine and pale stools due to cholestasis, where there is obstruction of bile flow. This can occur due to pancreatic cancer blocking the common bile duct
Which pancreatic enzymes don’t cause auto digestion?
Lipase and amylase, because they do not require activation after leaving the pancreas.
What is lipase released with?
Co-lipase which reduces the inhibitory effect of bile salts.
Which pancreatic enzymes cause auto digestion?
Proteases, therefore they are secreted as inactive zymogens.
What determines bile acid production in the liver?
The amount of intestinal reabsorption of bile acids in the liver, higher reabsorption will reduce production
What inhibits pancreatic secretion?
Somatostatin.
What is the neural stimulation for pancreatic secretion?
Stretching of the stomach
What stimulates emptying of the gallbladder?
Cholecystokinin- this is induced by fat entering the duodenum.
What is the main protease?
Trypsin, which is activated by enterkinase/enteropeptidase.
Enterokinase is produced in the duodenum
What does high foecal calprotectin mean?
IBD, either inflammatory bowel disease or ulcerative colitis.
What does high alpha-feto protein mean?
Hepatocellular carcinoma and foetal distress
What stimulates release of bicarbonate from the pancreas?
Secretin
Which antiarrythmic causes jaundice?
Amiodarone.
Which receptors mediate pancreatic secretion?
Muscarinic receptors M1 and M3
What stimulates insulin secretion from beta cells?
Sympathetic activation
What is the effect of dopamine agonists on GI system?
Reduces GI motility.
Which pancreatic cells produce bicarbonate?
Centroacinar cells
What does a very raised GGT indicate?
Alcoholic hepatitis
What is hepatorenal syndrome?
Liver damage so there is release of NO that causes a drop in peripheral resistance and decreased blood flow to kidneys. This increases RAAS activation so intrarenal vasoconstriction occurs, however this cannot overcome systemic effects of body. CAUASES AKI
Where are Brunner’s glands located?
Duodenum mucosa, which produces an alkaline fluid to protect the mucosa of duodenum from stomach acid.
Which part of the intestine is the only place that contains Peyer’s patches?
Ileum, which contains M cells
Where are M cells found?
Surface of MALT and Peyer’s patches for uptake of antigens to present to dendritic cells.
What is the role of Paneth cells?
Produces lysosomal enzymes into the lumen, to protect the crypt
