11th Edition By Jacqueline Burchum; Laura Rosenthal
gated open pores in the cytoplasmic membrane that regulate entry of calcium ions
into cells - ANSWER: Calcium channels
Calcium entry plays a critical role in the entry of what? - ANSWER: the function of
vascular smooth muscle (VSM) and the heart
In vascular smooth muscle, calcium channels regulate through what? - ANSWER:
contraction
What initiates the contractile process in VSM? - ANSWER: An action potential travels
down the surface of a smooth muscle cell, calcium channels open and calcium ions
flow inward
What happens when calcium channels are blocked in VSM? - ANSWER: Vasodilation
will result
Do CCBs have an effect on the veins? - ANSWER: No
CCBs act __________ on peripheral arterioles and arteries and arterioles of the heart
- ANSWER: selectively
In the heart, what do calcium channels help to regulate? - ANSWER: The
myocardium, SA node, and AV node
Calcium channels at their three sites in the heart are coupled to what receptors -
ANSWER: Beta1 adrenergic
In cardiac muscle, calcium entry have a positive or negative inotropic effect -
ANSWER: positive
Contractile force will diminish if calcium channels in the ________ and
____________ muscles are blocked - ANSWER: atrial and ventricular
What regulates the pacemaker activity of the SA node? - ANSWER: calcium influx
Does the discharge of the SA node increase or decrease when calcium channels are
open? - ANSWER: increase
The effect of calcium channel blockade (in SA node) is to - ANSWER: reduce heart
rate
, Regulation of _____________ plays a critical role in coordinating contraction of the
ventricles with contraction of the atria - ANSWER: AV conduction
The excitability of AV nodal cells is regulated by what? - ANSWER: calcium entry
The effect of calcium channel blockade (in AV node) is to - ANSWER: Decrease
velocity of conduction through the AV node
What similarities to beta blockers and CCBs have? - ANSWER: they have identical
effects on the heart
- reduce force of contraction
- slow heart rate
- suppress conduction through AV node
Nifedipine is the prototype of which CCB family - ANSWER: dihydropyridines
What is the only phenylalkylamine? - ANSWER: verapamil
what is the only benzothiazepine - ANSWER: dilitiazem
What calcium channel blocker affects the heart and blood vessels? - ANSWER:
Verapamil and diltiazem
What CCB acts mainly on blood vessels? - ANSWER: Nifedipine
What two dihydropyridines can help with migraines? - ANSWER: Nifedipine and
Nimodipine
What three dihydropyridines can help with angina? - ANSWER: Nifedipine,
amlodipine, Nicardipine
Verapamil and Diltiazem may be indicated for what conditions? - ANSWER: HTN
Angina
Dysrhythmias
Migraine
All CCBs are indicated for what? - ANSWER: HTN
What are the 5 direct effects Verapamil has on the heart/blood vessels? - ANSWER:
Blockade at:
1) peripheral arterioles causes dilation and thereby reduces arterial pressure
2) arteries and arterioles of the heart increases coronary perfusion
3) the SA node reduces heart rate
4) AV node decreases AV nodal conduction
5) in the myocardium decreases force of contraction