GI ILA formatives Flashcards
secreted by D cells; inhibit acid production
Somatostatin
secreted by enterochromaffin cells; stimulates acid production
histamine
Secreted by G cells; stimulates acid production
gastrin
Secreted by Cheif cells; no effect on acid production
pepsinogen
What is the main defence mechanism of gastric cells against damage by acid?
Mucus from goblet cells
How do aspirin & NSAIDs irritate the stomach?
By decreasing mucus synthesis through inhibition of prostaglandin production
What is the lower oesophageal sphincter?
- circular muscle of the gastro-oesophageal wall
- the acute angle made by the esophagus entering the stomach
- A motility pattern due to innervation from the vagus nerve branches from oesophagus down to the stomach
- The diaphragm
On prolonged exposure to acid, the cells of the lower oesophagus undergo metaplasia (reversible change from one cell to another). What does the epithelium change from and to?
stratified squamous to columnar
What is the action of the proton pump on the parietal cells of the stomach?
K+into cell, H+ out of cell
We are currently trying to design a drug that acts on histamine receptors on parietal cells to help patients with reflux disease. what would be the mechanism of this drug?
Inhibits Histamine 2 receptors to reduce acid secretion. (H2 found in gastric mucosa, H1 found in smooth muscle ie. Type 1 hypersensitivity in the lungs)
Describe the Vagal nerve action on parietal cells.
Vagus nerve is part of the parasympathetic system and releases acetylcholine onto parietal cells which stimulates acid secretion in the cephalic phase
which of the following is not a factor to develop reflux? A. obesity B. Sedentary lifestyle (being bare lazy) C. Pregnancy D. hiatal hernia E. Smoking
Sedentary lifestyle
What lies at the junction of the Right mid-clavicular line and the costal margin?
Gall bladder
What structure terminates at ampulla of Vater?
Common bile duct
Obstructive jaundice can be caused by gall stones within what structure? A. Pancreas B. cystic duct C. Gall bladder D. right hepatic E. Common bile duct
Common bile duct
What is situated within the duodenal loop?
Pancreas - more specifically the pancreatic head
microsomal enzyme uridine diphosphoglucourysl transferase (glucuronyl transferase UDPGT) catalyses the formation of what?
conjugated billirubin
bacterial enzyme hydrolysis in the gut produces a compound which is excreted in faeces….
stercobilinogen
which compound is returned to the liver by the enterohepatic circulation?
urobilinogen
absence of which compound causes pale stool in obstructive jaundice?
stercobilinogen
A 40 yr old chronic alcoholic come with c/o yellow discolouration of skin and an acutely painfu abdomen; he is thought to have acute pancreatitis. where does pain typically radiate in this condition?
Back
What are the levels of conjugated and unconjugated in the blood in a patient with pre-hepatic jaundice?
Normal conjugated
raised unconjugated
a diagnosed carcinoma in the head of the pancreas. What structure is affected to cause jaundice?
Common Bile duct
What is the cause of physiological jaundice of a newborn?
Excess breakdown of fetal haemoglobin
What causes increased serum bilirubin without any excess bilirubin in the urine?
Pre-hepatic jaundice
What is the central structure in a hepatic lobule
hepatic vein
Which cell is part of the reticuloendothelial system in the liver?
Kupffer cell (reticuloendothelial system - another name for machrophage system)
which of the following statements concerning salivary glands is true?
- Parotid gland secretions contain amylase
- salivary duct epithelial cells secrete Na+ and Cl-
- saliva is hypertonic
- the amount of saliva produced varies by race
- the parotid gland continuously produces saliva
Parotid gland secretions contain amylase.
(Amylase is produced by serous cells within salivary gland acini - as are found in the parotid. Salivary duct epithelial cells absorb Na+ and Cl-, rendering saliva hypotonic. A number of factors affect the rate of salivary secretion, but race isnt one of them. The submandibular, submental and minor salivary glands are continuously active but the parotid is not)
which of the following is not derived from endoderm?
- hepatocytes
- gut epithelial cells
- pancreatic endocrine cells
- pancreatic exocrine cells
- Smooth muscle in musculuaris propria of the gut
Smooth muscle in musculuaris propria of the gut actually derived from mesoderm
what causes the 3 indentations on a barium swallow?
Aortic arch
Left main bronchus
Left Atrium
which of the following statements about intestinal mucosa is true?
- Brunners glands are present in the sigmoid colon
- ascending colonic mucosa contains Paneth cells
- Peyer’s patches are present in the submucosa of the ileum
- stem cells are present in the tips of small intestinal villi
- transverse colonic mucosa has villous architecture
Peyer’s patches are present in the submucosa of the ileum.
The mucosa of the various parts of the large intestine and rectum are identical. It lacks villi and Paneth cells (these are features of small intestinal mucosa).
Brunner’s glands are found only in the duodenum.
Peyer’s patches are found in the submucosa, and may extend into the mucosa.
Stem cells are present in the crypts of Lieberkuhn, not the tips of the villi.
