Gastrointestinal Flashcards
What cells produce hydrochloric and and release intrinsic factor in stomach?
Parietal cells
What chemicals/Hormones are responsible for triggering/inhibiting gastric acid secretion?
Acetylcholine (Neural), Histamine (Hormone), Gastrin (Hormone) and Somatostatin (Hormone)
Which arteries supply the stomach?
Right and Left gastroepiloic (Greater curvature) and right and left gastric arteries (Lesser Curvature)
Which gastric cells produce Histamine
Enterochromaffin like cells (ECL cells)
Which nerve is involved in controlling release of Acetylcholine in the stomach?
Vagus Nerve
What are the 3 phases of digestion?
Cephalic phase - looking at food causing Vagus nerve stimulation
Gastric phase - food is inside stomach and stretching stomach. Cells sense protein and fat content causing release of gastrin and Histamine
Intestinal phase - food is stretching Duodenum causing enterogastric reflex . Somatostatin released by D cells and if fat detected then cholecystokinin released to induce gallbladder contraction
Where does alcohol and aspirin get absorbed
Stomach tissue
How many layers of muscle does the stomach have and what are they called?
The stomach has 3 layers
Outermost - longitudinal
Intermediate - Circular
Innermost - Oblique
What is the range of P.H of the stomach?
Resting 4 to 5
During digestion 1 to 2
What is the condition where the stomach acid causes metaplasia of oesophagus
Barrett’s oesophagus - conversion of oesophagus simple squamous epithelium into stomach columnar epithelium
What is the condition where the oesophagus will abnormally tighten around a bolus during peristalsis?
Nutcracker oesophagus
What is the ring of muscle that usually prevents backflow of stomach contents
Cardiac sphincter and lower oesophageal sphincter
Diaphragm helps prevent backflow
Angle of oesophagus to stomach helps prevent backflow
What is the condition where the stomach passes through the diaphragm
Hiatus hernia
What is the name of the condition where stomach acid will consistently travel up the oesophagus causing heartburn
Gastro reflux disease
Most common cause of gastric ulcers
Heliobacter pylori bacteria
What is Ranitidine
A competitive Histamine inhibitor which reduces hydrochloric acid secretion
What is Omeprazol
A proton pump inhibitor which stops secretion of HCl by 90% by inhibiting parietal cells
What cells prevent gastric tissue from being damaged by gastric acid
Mucosal neck cells which produce mucous layer to prevent acid touching stomach tissue
Names of the different sections of the small intestine
Duodenum, Jejunum and Illeum
Why is pepsin in the form of pepsinogen?
It’s to allow for pepsin to be stored in chief cells and allow activation when exposed to acid. Also prevents breakdown of stomach tissue
Which enzyme actives trypsinogen
Enterokinase
What does trypsin do?
It activates pancreatic digestive enzymes such as procarboxypeptidase or proelastase
Which type of enzymes do the duct and acinar cells of the pancreas release
Digestive enzymes
Which enzymes do the islets of langerhans release
Insulin, Glucagon and Somatostatin
Which cells make up the liver?
Hepatocytes, endothelial cells, perisinusoidal cells (fat cells), liver associated lymphocyte and Kupfer cells
What are the main function of hepatocytes
They regulate the metabolic functions of the liver and allow for veins and arteriolar blood to enter the liver
What is the function of Kupfer cells
Immune protection for the liver
What is the name of the duct that connects both the pancreas and gallbladder
Duct of ampulla
What controls the release of both pancreatic and gallbladder contents
Sphincter of Oddi
What gastro bacteria causes yellow blotches on the damn intestine
C. Difficule
Symptoms of Haemolytic Uraemic Syndrome
Microangiopathic Haemolytic Anaemia - anaemia caused by damage to red blood cells
Acute renal failure
Thrombocytopenia - lack of platelets
How much water is lost through insensible loss
700mL
Where are most water and electrolytes reabsorbed
Duodenum
Name of treatment for GORD involving a ring around the oesophagus
Linx treatment
GORD treatment top of stomach is wrapped around the oesophagus
Nissen procedure
AST > 3X and ALP < 2X
Hepatocellular Disease
AST < 3X and ALP > 2X
Cholestatic Disease. Ultrasound determines if it’s Intrahepatic or Extrahepatic
What is Gilbert Syndrome?
A genetic condition where there is a lack of Uridine diphosphate Glucorinic Transferase (UGT) causing build up of unconjugated bilirubin during stress
Which lobe of the liver has the porta hepatis
Quadrate lobe
Which zone in the hepatic acinus has mainly oxidative metabolic processs
Zone 1. Includes gluconeogenesis, beta oxidation of fatty acids
What does zone 3 at the hepatic acinus do?
Mainly non oxidative processes such as xenobiotic metabolism, glycolysis
Which 3 vessels form the portal vein
Splenic vein, superior mesenteric vein
What’s a common sign of portal hypertension
Spider navei, varicose veins, caput medussae, ascites (fluid in abdomen)
What is physiological saline?
0.9% saline sodium chloride
What is given in I.V if patient needs fluid with no electrolytes
5% Dextrose Fluid
What is cirrhosis?
End stage liver failure. Result of chronic inflammation over many years.
Persistent scarring and hyperplastic nodules which causes fibrosis and hepatocytes loss
What is a common cause of cirrhosis?
Alcoholic damage
What causes coeliac disease
An autoimmune reaction to gluten and an inability to digest gluten due to a lack of protease
How is iron absorbed
Ferric iron absorbed directly into entetocytes through divalent metal transporter
Non-ferric iron gets reduced by cytochrome B into ferric iron and then goes through DMT into enterocyte
What are Paneth cells and where are they found?
Paneth cells are found in the bottom of the crypts of liberkuhn in the small intestine.
They provide immune cells which prevent colonisation of bacterial in the small intestine
What epithelium does the large intestine have?
Columnar absorptive cells
What is Taenia coli?
Longitudinal bands of smooth muscle which help provide motility
How are fats absorbed in the small intestine?
They are broken down into small fatty acids by pancreatic lipases and then converted into Micelles - small droplets of fat with a hydrophilic lecithin outer layer.
Micelles enter small intestine and are then converted into chylomicrons by being combined with proteins. They are then brought into lacteals and taken to the liver
How are proteins absorbed?
They are broken into short chain amino acids by pancreatic enzymes and then taken into enterocytes via active transport using H+ ions
How much of the tongue is skeletal?
The superior 1/3
Other 2/3 are smooth muscle
What are brunner glands and what do they do?
They are glands which produce a very alkaline mucus and help to neutralise the acid chyme produced in the stomach
Found in the duodenum
What bacterial infection places a patient at risk of developing Gullain Baree syndrome
Campylobacter
Which bacteria is known for causing secretory Diarrhoea
Cholera.
Cholera causes over activation of adenylyl Cyclase which increases cAMP concentration in small intestine crypts of liberkuhn enterocytes causing significant secretion of water into stool
