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Why Does Calcium Channel Blocker Cause Relaxation Of Muscles And Dilation Of Vessels?
Question: Hi,
Can you tell me why a calcium channel blocker would cause relaxation of muscles and dilation of vessels, but hypocalcemia would cause hyperexcitability and possible tetany? This is very confusing to me.
Can you tell me why a calcium channel blocker would cause relaxation of muscles and dilation of vessels, but hypocalcemia would cause hyperexcitability and possible tetany? This is very confusing to me.
Brief Answer:
the answer is below
Detailed Answer:
Hello and thank you for asking HCM,
I will try to explain. Calcium blockers block the entry of calcium which prevents contractions, which means that without calcium your muscles (skeletal and smooth) cannot contract. During hypocalcemia, there is a change in membrane excitability, which leads to hyperexcitability.The main reason hypocalcemia causes neural excitability and tetany is due to its effect on the threshold potential of nerve axons. Low calcium reduces the amount that the threshold must change to initiate a full depolarization of the axon while leaving the resting potential unchanged. So depolarization which is needed for contraction and inervation is faster and shortened.
On the other hand, hypercalcemia leads to saturation channels and inability to release calcium from the cell leading to fatigue of cell.
I hope this answer was helpful to you.
the answer is below
Detailed Answer:
Hello and thank you for asking HCM,
I will try to explain. Calcium blockers block the entry of calcium which prevents contractions, which means that without calcium your muscles (skeletal and smooth) cannot contract. During hypocalcemia, there is a change in membrane excitability, which leads to hyperexcitability.The main reason hypocalcemia causes neural excitability and tetany is due to its effect on the threshold potential of nerve axons. Low calcium reduces the amount that the threshold must change to initiate a full depolarization of the axon while leaving the resting potential unchanged. So depolarization which is needed for contraction and inervation is faster and shortened.
On the other hand, hypercalcemia leads to saturation channels and inability to release calcium from the cell leading to fatigue of cell.
I hope this answer was helpful to you.
Above answer was peer-reviewed by :
Dr. Yogesh D
Dear Dr. Romic,
It really does help thank you so much! I find it difficult to memorize lists of reactions without knowing the mechanism of action. Thanks for taking the time to answer. The electrolytes are driving me crazy. XXXXXXX
It really does help thank you so much! I find it difficult to memorize lists of reactions without knowing the mechanism of action. Thanks for taking the time to answer. The electrolytes are driving me crazy. XXXXXXX
Brief Answer:
Welcome
Detailed Answer:
I am glad it helped you.
Please close the discussion if you have no more questions..
Welcome
Detailed Answer:
I am glad it helped you.
Please close the discussion if you have no more questions..
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Above answer was peer-reviewed by :
Dr. Prasad
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