Flashcards in Heart Week 1C: Drugs and stuff Deck (21):
Tell me about class 1a, 1b and 1c drugs
1a: short dissociation time (1-10 sec), middle Na channel blocker, repolarization time is prolonged, eg- quinidine, disopyramide
1b: dissociation time < 1sec, weak Na+ channel blocker, repolarization time is shortened, eg- lidocaine
1c: disassociation time (>10sec) great Na+ channel blockers, repolarization time unchanged, eg- flecainide, encainide
tell me about beta blockers
a. affect phase 4 and L-Ca++ channels
b. repolarizatoin time is slightly shortened
c. propranolol is an example
d. surpresses sympathetic nervous system
Tell me about adenosine.
a. opens Ka+ channels hyperpolarizing,
b. repolarization time is unchanged
c. cardio-protective: lowers O2 demand, increases 02 supply
d. contra-indicated with asthma
e. chief indication is PSVT
What are the must know Class I drugs?
What is the must know Class II drugs?
What is the must know Class III drug?
amiodarone: it prolongs phase 3
What are the must know Class IV drugs?
What are two types of cholinergic receptors?
muscarinic (metabotropic) and nicotinic (ionotropic).
Are beta receptors for the sympathetic or parasympathetic system?
What molecule does adrenergic receptors respond to?
What types of adrenergic receptors are there?
2: alpha and beta
What nervous system do alpha and beta adrenergic receptors respond to?
alpha = parasympathetic
beta = sympathetic
What type of receptors are adrenergic receptors, direct or 2nd messengers?
G-protein coupled receptors.
What is the Starling principle?
The greater the volume of blood, the larger the stroke volume.
How big are arterioles? How can they be identified?
10-60microns in diameter. They can be identified by 1-5 continuous layers of smooth muscle.
Where are purkinje fibers in histology?
They are sub endocarium, and are balloon/bubble gum shaped as opposed to the striated muscles.
arteries are characterized by what?
>5 layers of smooth muscle, prominent internal and external elastic laminae,
What are characteristics of arterioles?
1-5 layers of smooth muscle, internal/external elastic laminae may or may not be present, 10-100 microns in diameter.
What are characteristics of capillaries?
Diameter just big enough for a RBC, no smooth muscle.
What are are some differences between venules and veins?
venules are a little bigger than capillaries, walls is only endothelium and thins layer of connective tissue.
small and medium veins contain some smooth muscle that is circularly oriented.