Calcium Channel Blockers
- 1.Calcium channel blockers can be divided into three class based on their chemical structure. Which of the following is not a class of calcium channel blockers?
- A.
Nitrates
- B.
Penylalkylamines
- C.
Dihydropyridines
- D.
Benzothiazepines
- 2.Calcium channel blockers can be used as anti-anginal drugs.
- A.
True
- B.
False
- 3.Which of the following are classified as "dihydropyridines" of the calcium channel blockers?
- A.
Nicardipine
- B.
Amlodipine
- C.
Diltiazem
- D.
Nifedipine
- E.
Verapamil
- F.
Felodipine
- 4.In addition to angina, calcium channel blockers can be used therapeutically in the treatment of which of the following diseases?
- A.
Essential hypertension
- B.
Cardiac arrhythmias
- C.
Type II Diabetes
- 5.Calcium enters excitable cells via potential or voltage-dependent calcium channels, which are similar to other ion channels.
- A.
True
- B.
False
- 6.Which of the following is NOT a type of calcium channel?
- A.
L
- B.
S
- C.
N
- D.
T
- 7.Calcium is responsible for the __________ of muscle.
- 8.Which type of calcium channel do the calcium channel blockers selectively inhibit?
- A.
N
- B.
T
- C.
L
- 9.Calcium channel blockers allow calcium movement from outside the cell to inside the cell through their channels.
- A.
True
- B.
False
- 10.Which of the following are characteristics of the L type calcium channels?
- A.
Long lasting current
- B.
High conductance
- C.
Large channels
- D.
Enriched in the neurons
- E.
Enriched in cardiac and smooth muscle, in the SA node and Purkinje cells
- F.
Blocked by spider and snail toxins
- G.
Blocked by calcium channel blockers
- 11.Because L type calcium channels are enriched in the cardiac and smooth muscle, SA node, and Purkinje cells, they play an important role in __________.
- A.
Contration, heart rate, and conduction
- B.
Neurotransmitter release
- 12.Which of the following are characteristic of the T type calcium channel?
- A.
Found in the SA node and Purkinje cells
- B.
Tiny, transient current
- C.
Intermediate current
- D.
Blocked by calcium channel blockers
- E.
Blocked by spider and snail toxins
- F.
Very small calcium entry
- 13.T type calcium channels were once a target for anti-anginal drugs as they are located in the SA node and Purkinje cells, playing a role in pacemaker activity and conduction, but the ones developed were found to be toxic. It is still a possible area for development of anti-anginals.
- A.
True
- B.
False
- 14.Which of the following are characteristic of N type calcium channels?
- A.
Large conductance
- B.
Small conductance
- C.
Intermediate conductance
- D.
Blocked by calcium channel blockers
- E.
Blocked by spider and snail toxins
- F.
Enriched in neurons
- G.
Enriched in cardiac muscle
- H.
Play a role in neurotransmitter release
- 15.Which of the following is not true regarding L-type calcium channels?
- A.
Widespread in cardiovascular system
- B.
Activated when the cell is depolarized
- C.
Large conductance of long lasting duration
- D.
Inhibited by calcium channel blockers
- E.
Responsible for the upstroke of the cardiac action potential
- F.
Responsible for the plateau phase of the cardiac action potential
- 16.Calcium channel blockers exhibit a mechanism of action in both cardiac cells and vascular muscle cells.
- A.
True
- B.
False
- 17.In vascular smooth muscle, contraction is dependent upon an increase in intracellular calcium. Which of the following occurs when calcium enters a vascular smooth muscle cell?
- A.
Calmodulin activates myosin LC kinase to phosphorylate myosin LC
- B.
Calcium binds to calmodulin
- C.
Calmodulin inhibits myosin LC kinase, so myosin LC cannot be phosphorylated
- D.
Phopshorylated myosin LC interacts with actin
- E.
Contraction occurs because phosphorylated myosin LC interacts with actin
- 18.Which of the following occurs because calcium entry into vascular smooth muscle is blocked by calcium channel blockers?
- A.
Contraction
- B.
Relaxation
- 19.By preventing calcium entry, calcium channel blockers are thereby stopping which of the following mechanisms from occuring?
- A.
Calcium's binding to calmodulin
- B.
Calmodulin's activation of myosin LC kinase
- C.
Phosphorylated myosin LC's interaction with actin
- D.
Contraction
- 20.Calcium channel blockers have a much more prominent effect in decreasing vascular smooth muscle contraction in arteries.
- A.
True
- B.
False
- 21.The relaxation produced in coronary and peripheral vascular smooth muscle decreases peripheral resistance, which results in which of the following?
- A.
Decrease pressure and decreased cardiac preload
- B.
Increased pressure and increase cardiac preload
- C.
Decreased pressure and decreased cardiac afterload
- 22.Through their mechanisms, calcium channel blockers work in angina because they reduce the oxygen demand (through decreasing resistance), as well as increase the oxygen supply (through relaxation of the arteries).
- A.
True
- B.
False
- 23.Calcium channel blockers have a large effect on the veins, as well as the cardiac preload.
- A.
True
- B.
False
- 24.Calcium entry is responsible for which phase in the action potential?
- A.
Phase 0
- B.
Phase 1
- C.
Phase 2
- 25.Calcium channels are sometimes called slow channels because of their delayed response in the cardiac action potential.
- A.
True
- B.
False
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