Mechanism of muscle contraction : the sliding filaments theory

Mechanism of muscle contraction : the sliding filaments theory


Huxley depended in his theory on the microscopic structure of the muscle which allows us to see the thin actin filaments drown as horizontal blue line the z-line drown as vertical blue line thick Myosin filament is drown as bold horizontal black line hooks of Myosin Huxely used an electron microscope to compare muscle fibre in a state of relaxation with another fibre in a state of contraction and he discovered that the actin filaments slide over the myosin filaments that’s because the hooks in persence of calcium & ATP pull the actin filaments then they are detached from the actin filaments and return to its original position then they pull the actin again and again and the cycle repeats over and over again until the muscle reaches its maximum degree of contraction where the most possible shortening of the muscle occurs then the actin filaments couldn’t be pulled anymore so it remains in this position and the hooks stay attached to actin it is only detached if there is enough ATP if there isn’t enough ATP the hooks will remain attached to the actin leading to muscle spasm where the muscle remains contracted but as we said if there was enough ATP and the hooks detaches from the actin the actin filaments will return to their original position and the muscle length will return to normal and the muscle can enter a new cycle performing another contraction there is a lot of steps and details that happen but they are not for 3rd secondary students you gonna know them through your study of medicine sth known as excitation contraction coupling but if you want to know more than what you have let us know at the comments below thumbs up if you liked this video subscribe if you ain’t already to stay updated

Leave a Reply

Your email address will not be published. Required fields are marked *