Hello viewers in this video i had explained about #calciumchannelblockers #antihypertensive #amlodipine #diltiazem #mechanismofaction #drugs #nursing #nursingmasters #medical #medicalsurgicalnursing #pathology #pharmacology #calciumchannel #nclexrnexam
So before we discuss mechanism of action we know that calcium plays very important role as many of the medical and nursing students know about calcium ions is that it is very important for bone formation it is very it plays very important role in blood clotting yes blood clotting blood clotting and muscle contraction yes we have a video on physiology of muscle
Contraction you can also we can check that video muscle contraction right okay now we are going to discuss about the mechanism of action before that we have to understand the basic physiology of the pacemaker cells in the heart and non pacemaker cells how they actually work so let’s let’s discuss these things so these there are the channels on the pacemaker cells
Known as funny sodium channels and whenever there is action potential the sodium ions in flux occurs sodium ions flow inside the cell pacemaker cells and make it more electro positive make it more electro positive or we can say less electronegative as the cell membrane as the cell environment cell environment becomes more and more positive the voltage sensitive
Calcium channels are stimulated voltage sensitive calcium channels are stimulated which leads to influx of calcium and then what happens we know that yes the cell becomes more and more electro positive which further which further stimulate the l-type calcium channels yes ladies and gentlemen this further stimulate l-type calcium channels and then happens wow then
Happens more and more calcium blast inside the cell inside the pacemaker cell we can say so therefore and making the cell more and more electro positive and generating yes please action potential in the pacemaker cells we know that pacemaker cells are present in the cyanoatrial node sa node and av node now as the cell is becoming more and more electro positive the
We can say shifting of shifting of this positive ions or action potential across the membrane occurs between the two types of cells first is spacemaker cells and others are non-pacemaker cells through the gap junction we know that cells are having gap junctions for exchange of different type of ions and substances so as these ions or action potential is moving or
Shifted towards the non-pacemaker cells of the myocardium we can say myocardial muscles it is becoming more and more electro positive which further uh we can say opens the voltage sensitive funny sodium channels i actually am using the word funny but they are not funny they are just sodium channels and there is inflow of sodium ions inside the non pacemaker cells
Which further increases the cell electrode we can say positivity and as this occurs we had already studied in the physiology of muscle contraction that whenever a skeletal muscle or smooth muscle is stimulated the action potential shift to across the membrane inside the membrane and finally it reaches finally it reaches towards the twos twos if you don’t know
About t tubules you can check our video on physiology of muscle contraction so now we know that twos are having sarcoplasmic reticulum around them which are very very excellent source of calcium so after the stimulation of t tubules and release of calcium now the further calcium we can see voltage sensitive calcium channels also open up which further increases
Blast of calcium inside the cell blast of calcium inside the cell this makes non pacemaker cells further more and more electro positive and this calcium as we know binds on the actin and myosin further helping in cross bridging of them and muscle contraction wow muscle contraction occurs so ladies and gentlemen till now we had discussed that calcium is the king
Calcium is the king in functioning of physiology of pacemaker cells and non pacemaker cells so now it is very easy for you and me to understand basically what the calcium channel blockers will do they will just just and just block the calcium channels excellent calcium channels are blocked will the cell be able to become more electropositive no and will the
Pacemaker cells able to stimulate these non-pacemaker cells absolutely no and can there be influx of calcium ions inside the both cells no so till now we had seen that how the understanding of basic physiology helped to understand the concept of mechanism of we can say calcium channel blockers or drugs so similarly on the walls on the walls of we can say blood
Vessels we are having smooth muscle layer this smooth muscle layer is known as tunica media so the cells of tunica media cells of tunica media for the purpose of vasoconstriction and vasodilation i am repeating for the purpose of vasodilation and vasoconstriction are dependent upon calcium inflow once again the king calcium inflow calcium inflow this is the
Example of vascular cells present in the smooth muscle layer of the blood vessels blood vessels ladies and gentlemen now we are discussing about the vascular cell so calcium will further bind with calmodulin we know that call modeling is very important then it will stimulate can kinase then it will stimulate mlck we had already discussed mlck cam kinase in the
Video of muscle contraction so briefly discussing mlck light chain kinase will stimulate actin myosin cross bridging ultimately actin myosin cross bridging will occur which will cause muscle contraction if we block these calcium channels will this process occur no will there be any cross bridging between actin and myosin absolutely no so this muscle contraction
Will not occur and the blood vessels diameter will further further increase do what do you think that whenever we increase the diameter of the blood vessel it is known as yes please vasodilation and whenever the diameter of a blood vessel increases the blood pressure falls blood pressure falls according to the rules of the physics so what do you think it will
Be help helpful in what patients case so if we already discussed during the starting of the lecture in a funny manner if a person’s blood pressure is increasing or sustainably increasing and is hypertensive it is quite useful drugs absolutely drugs these drugs are the initial we can say starting drugs for the use for the treatment of we can say hypertension
Basically the patients are started with the calcium channel blockers these calcium channel blockers kindly note are synthetic drugs which were invented in 1964 1964 is the year of their invention and they are responsible for blockage of calcium channel blockers and 30 to 40 percent 30 to 40 percent patients uh are with diuretic sorry with hypertension are
Prescribed calcium channel blockers and we can say diuretic drugs we had already a video on ace inhibitors and loop diuretics in that video we had already discussed that the patients with hypertensive we can say behavior or pattern whom the bp is high or rising we are prescribing them loop diuretics and calcium channel blockers so in this way not only calcium
Channel blockers are useful for the hypertensive patients but if you uh we can say think about a moment that heart has to pump more because the blood pressure is more heart has to pump more and heart rate will increase if we decrease bp if we decrease blood pressure myocardium layer obvious has to work less therefore it is also useful in case of we can say heart
Disorders cardiac disorders especially myocardial infarction because these drugs will decrease workload on the myocardial layer so students we had discussed about the mechanism of the action that by blocking the calcium channels in both pacemaker non-pacemaker cells and vascular system these drugs work
Transcribed from video
Calcium Channel Blockers || Mechanism of Action || Amlodipine || Diltiazem || Antihypertensive Drugs By nursing masters
