Doctors prescribe calcium channel blockers to control high blood pressure. They work by blocking the channels that allow calcium ions to diffuse into the sarcoplasm of muscle fibres, such as those found in cardiac muscle.
What role does calcium play in muscle contraction?
Extension question: (this is second year material but give it a go) How do you think blood pressure/hypertension is controlled with this medication?
Calcium is an important ion that is neccessary for muscle contractility. Calcium channel blockers as the name suggests, work by blocking/slowing the influx of calcium into the heart and the smooth muscle of the blood vessels. By slowing the calcium intake this lowers blood pressure through vasodilation of the blood vessels, reducing resistance therefore making it easier for the heart to pump blood.
ReplyDeleteVery basic, but is that along the right track? :). Thankyou for the questions Sophie! It puts your knowledge into perspective when you actually have to apply it! Are there any more applied type questions you can give us to work through?
DeleteCompletely along the right track Kate! You and Beth are on fire! That is as much as you need to know at this stage well done. I will post some more applied questions on Thursday..watch this space!
ReplyDeleteWell done girls.
Wow Kate!!! Great answer :)
ReplyDeleteJust to reinforce the role of calcium (for my own learning!)
Along the thin filaments (within a myofilament) are proteins called troposin and Troposymin (as well as actin). The Troposymin cover or block the active sites for myosin and troposin are attached to the Troposymin. When calcium is released from the sarcoplasmic reticulum it binds with the troposin and unlocks Troposymin for the actin, exposing the myosin active sites. Now myosin can bind in the active sites and allow muscle contraction.
And Kate brilliantly explained how the reduction in calcium intake will control the muscle contraction within the heart.
Sophie can I please clarify the calcium channel blockers prescribed for hypertension just affect the cardiac mucle?
Thanks :)
No Beth, they affect the arteries as well.
ReplyDeleteThank Soohie. Do they affect skeletal and smooth muscle?
ReplyDelete