BMS10-1030 Pharmacology & the Cardiovascular System Flashcards
Perfusion pressure
Difference in pressure between arteries and veins
Which is the main regulator of this?
Sympathetic nervous system
What does the baroreceptor response alter? (3)
Cardiac, vascular and renal function
What may cause postural hypotension?
Side effect of drugs that block the SNS
Why do we get venous pooling?
The veins are more elastic
What 3 variables must you consider before giving drugs?
Arterial blood pressure
Peripheral resistance
Heart rate
What can changes in diastolic BP indicate?
Changes in peripheral resistance; it is the main factor as valves are closed in diastole so the heart isn’t pumping blood into arteries
What can changes in systolic BP indicate?
Peripheral resistance and cardiac out put as in systole blood is being pumped out into arteries so increasing both of these increases BP
What does noradrenaline (alpha agonist) do?
Constrict smooth muscles increases resistance and therefore BP so we begin bradycardia
What does isoprenaline (beta agonist do)
Relax smooth muscle so heart rate and force increases decreasing resistance but increasing CO so MABP decreases
What does adrenaline (beta and alpha agonist) do?
Mainly constrict to increase rate and force to reduce resistance and increase CO to increase mean BP
What will a B2 isoprnaline do?
Relax smooth muscle to decrease resistance
What do B1 and baroreceptors do?
Increase HR and force to increase CO
What are some affects of alpha agonists?
Relax gut
Dilate pupils
Glycogen mobilsation
What are some affects of beta agonists?
Relax bronchial
Relax gut
Glycogen and fat mobilisation
Why may we want to raise BP?
Treat hypotension or hypovolaemic shock
How can we prolong the action of drugs?
Used with anaesthetics to slow absorption
Name drugs that raise BP
alpha adrenergic agonists
beta adrenergic agonists
vasopressin receptor agonists
What do alpha adrenergic agonists do?
Constrict smooth muscle
What do beta adrenergic agonists do?
Increase CO
What do alpha blockers do?
Decrease peripheral vascular tone to lower BP
What do beta blockers do?
Lower blood pressure by decreasing cardiac output
What may drugs to do lower pressure in the kidney?
Deactivate enzymes
What may drugs do in muscle cells to lower BP?
Stop calcium entry so they cant contract or make lots of K leave so its harder to depolarise
Add NO so Ca cant enter
What are diuretic drugs?
Used to reduce blood volume
Renin angiotensin system
Stop constriction and reduce blood volume
