Drugs and the Gut Flashcards
Antagonist
A drug or chemical that interferes with the physiological action of another, especially by combining with and blocking its receptor
Agonist:
Agonist
A drug or chemical that can combine with a receptor on a cell to produce a physiologic reaction typical of a naturally occurring substance.
Receptor:
Receptor
Any of various specific protein molecules in surface membranes of cells and organelles to which complementary molecules, eg hormones, neurotransmitters, may be bound.
Irreversible binding
Irreversible binding: An irreversible antagonist binds covalently to the receptor and cannot be displaced by either competing ligands or washing.
Side effect
Problems that occur when treatment goes beyond the desired effect. Or problems that occur in addition to the desired therapeutic effect
what is Abdominal discomfort indicative of
Peptic Ulcer (upto 1 in 8 people)
Gastro esophageal reflux
Vomiting
where do peptic ulcers form
Form in stomach (Stomach ulcer) or the digestive tract (duodenal ulcers).
symptoms of peptic ulcers
Pain intheabdomen/neck/navel/back. Bleeding Indigestion Heartburn Loss of appetite Vomiting Can no longer tolerate fatty foods
pain of peptic ulcer
Can last from a few minutes to a few hours
If a stomach ulcer usually startssoonafter eating a meal.
If the ulcer is in your small intestine, pain may start two to three hours after eating.
describe the pain of stomach ulcers
no typical symptoms and can cause no pain
how does plain work in stomach ulcers
get complication withoutpain.
where are neck cells
cardiac, pylori, fundus
where are chief cells found
fundus
where is parietal/oxyntic
fundus
what do the gastric glands secrete
gastric Juice ( HCL + enzymes + mucus
what does Neck cells secrete
mucus
what does Chief cells secrete
proteolytic enzymes (digestive)
what does Parietal / oxyntic cells secrete
HCL
how is acid secreted
H+ ion is pumped into the lumen, in exchange for K+ via proton pump
where is hydrogen ion generated and what happens after
Hydrogen ions are generated within the parietal cell from dissociation of water. The hydroxyl ions formed in this process rapidly combine with carbon dioxide to form bicarbonate ion, a reaction cataylzed by carbonic anhydrase.
what happens after Bicarbonate is transported out of the basolateral membrane in exchange for chloride
. The outflow of bicarbonate into blood results in a slight elevation of blood pH known as the “alkaline tide”. This process serves to maintain intracellular pH in the parietal cell.
how are Chloride and potassium ions are transported into the lumen of the cannaliculus and why is this important
conductance channels and such is necessary for secretion of acid.
what happens when hydrogen ions are pumped out of the cell into the lumen
this is done in exchange for potassium through the action of the proton pump; potassium is thus effectively recycled
what happens when there is an accumulation of osmotically active hydrogen ion in the cannaliculus
generates an osmotic gradient across the membrane that results in outward diffusion of water - the resulting gastric juice is 155 mM HCl and 15 mM KCl with a small amount of NaCl.
