block a lecture 3 Flashcards
where do drugs act
what is a transporter
a protein which helps move molecules across a membrane in or out of the cell
2 examples of generic transporters
glucose transporters
moving glucose in the liver and skeletal muscle
aa transporters in the intestine to take aa into the body
chemical name of the serotonin neurotransmitter
5-hydroxytryptamine
5-HT
where is 5-HT released from and what does it affect
released from nerve cells in the brain and affects other target nerve cells increasing activity
what receptor does it interact with
5-HT receptor on target cells
what type of neurotransmitter is 5-HT known as
excitatory neurotransmitter
5-HT is an excitatory neurotransmitter, what is the effect on brain activity
increases brain activity
what does SSRI stand for
selective serotonin re-uptake inhibitor
what does fluoxetine block
blocks the 5HT reuptake transporter
what does more 5HT hanging around in the space between the 2 neurons lead to
more likely to stimulate the 5HT receptor on target neuron
-more activity
-better mood
what does a proton pump transport
H ions
what does an anti porter do
one mol in one direction and the other in counterdirection
with omeprazole why are H ions moved to the gut
because low pH is needed in stomach
what does too much acid in the stomach lead to
ulcers
3 medical uses of proton pump inhibitors
peptic ulcers
GERD
gastrin producing tumour
why do peptic ulcers arise
too much acid damages stomach lining
what does GERD stand for and what is it/lead to
gastroesophageal reflux disease
sphincter doesnt shut properly-acid into the oesophagus
what is a gastrin producing tumour
a pancreatic tumour which produces too much gastrin
what does gastrin stimulate
stimulates parietal cells to release acid
what are ion channels
pores in the membrane made up of proteins
4 different types of channels
ligand gated
mechanically gated
always open
voltage gated
cells that are excitable have lots of ion channels
why is this
because the cells have to respond quickly
examples of cells that have lots of ion channels
nerve cells
skeletal cells
muscle cells
heart cells
how quickly do ion channels open
miliseconds
what are the charges outside and inside the cell
-ve outside
+ve inside
what is an action potential
change in membrane potential
6 stages of action potential
1- Na channels open, Na enters the cell
2- K channels open, K leaves the cell
3- Na channels become refractory, no more Na enters cell
4- K still leaves cell causing membrane poten. to return to normal
5- K channels close, Na channels rest
6- extra K outside diffuses away
where does action potential relay down
the nerve
until it gets to the end organ where transmitter release happens
what are the 3 classes of sodium channel blockers
class 1A
class 1B
class 1C
what is the mnemonic for the class 1A of sodium channel blockers
double quarter pounder
what is the mnemonic for the class 1B sodium channel blockers
lettuce tomato pickles
what is the mnemonic for the class 1C sodium channel blockers
fries please
names of the class 1A sodium channel blockers
Disopyramide
Quinidine
Procainamide
names of the class 1B sodium channel blockers
Lidocaine
Tocainide
Phenytoin
Mexiletine
names of the class 1C sodium channel blockers
Flecainide
Propafenone
mechanism of action of lidocaine
blocks the channel from inside the cell
why does the use of lidocaine result in no pain
no action potential
2 other pain meds that are used similarly to lidocaine
benzocaine
bupivicaine
what do Ca2 channels in the vascular smooth muscle do
mediates contraction
controls blood pressure
