Heart Week 1C: Drugs and stuff

Question 1

Tell me about class 1a, 1b and 1c drugs

Answer 1

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

Question 2

tell me about beta blockers

Answer 2

a. affect phase 4 and L-Ca++ channels
b. repolarizatoin time is slightly shortened
c. propranolol is an example
d. surpresses sympathetic nervous system

Question 3

Tell me about adenosine.

Answer 3

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

Question 4

What are the must know Class I drugs?

Answer 4

quinidine, lidocaine

Question 5

What is the must know Class II drugs?

Answer 5

propranolol

Question 6

What is the must know Class III drug?

Answer 6

amiodarone: it prolongs phase 3

Question 7

What are the must know Class IV drugs?

Answer 7

a. verapamil
b. diltiazem
c. adenosine

Question 8

What are two types of cholinergic receptors?

Answer 8

muscarinic (metabotropic) and nicotinic (ionotropic).

Question 9

Are beta receptors for the sympathetic or parasympathetic system?

Answer 9

sympathetic.

Question 10

What molecule does adrenergic receptors respond to?

Answer 10

norepinephrine.

Question 11

What types of adrenergic receptors are there?

Answer 11

2: alpha and beta

Question 12

What nervous system do alpha and beta adrenergic receptors respond to?

Answer 12

alpha = parasympathetic
beta = sympathetic

Question 13

What type of receptors are adrenergic receptors, direct or 2nd messengers?

Answer 13

G-protein coupled receptors.

Question 14

What is the Starling principle?

Answer 14

The greater the volume of blood, the larger the stroke volume.

Question 15

How big are arterioles? How can they be identified?

Answer 15

10-60microns in diameter. They can be identified by 1-5 continuous layers of smooth muscle.

Question 16

Where are purkinje fibers in histology?

Answer 16

They are sub endocarium, and are balloon/bubble gum shaped as opposed to the striated muscles.

Question 17

arteries are characterized by what?

Answer 17

> 5 layers of smooth muscle, prominent internal and external elastic laminae,

Question 18

What are characteristics of arterioles?

Answer 18

1-5 layers of smooth muscle, internal/external elastic laminae may or may not be present, 10-100 microns in diameter.

Question 19

What are characteristics of capillaries?

Answer 19

Diameter just big enough for a RBC, no smooth muscle.

Question 20

What are are some differences between venules and veins?

Answer 20

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.

Question 21

On an EKG, what are the normal values for: Vent. rate, PR, QRS, QT, PRT axes?

Answer 21

a. vent rate: 60-100
b. PR: 120-200
c. QRS < 120
d. QT < 450 (male)
e. PRT axes: -30 to 90