Mechanism of Muscle Contraction
How Do the Muscles Contract
Mechanism of muscle contraction will help to analyse the functioning of the muscles and thereby the importance of the muscles can be ascertained. How do the muscles contract is specifically understood by knowing the functioning of the motor neurons, muscle fibres and the axon. Along with that, the sarcomeres too tend to shorten up by 60-70 % in the process.
Muscle is an organ of the human body which is primarily responsible for transforming chemical energy in to the movement. Movement is a way of life. Muscles in fact consist of a number of proteins which help them in the movement process. The prime meaning of the word contraction though is shortening but with regard to the mechanism of muscles, the term stands for generation of tension with the help of motor neurons.
The study of muscle contraction is taking place around the world and this basically involves biophysical techniques. These may also include the study of protein crystallography, low angle x-ray differentiation, electron microscopy etc.
Process Involved in Muscle Contraction
Muscles are said to be primarily composed of muscle fibres which in turn consist of various groups. A single motor neuron called as axon controls each group. Motor neuron and the muscle fibres which are grouped together form the motor unit. When stimulation is provided to the muscles, it takes time to build up the stimulus but then it contracts and in this period they will become short and thick. The final result is that they elongate and get back into the relaxation mode.
The muscles are primarily of three types- skeletal muscles which are responsible for locomotion and flight, cardiac muscles which help in the heart to function effectively and properly and the smooth muscles which are known to control the blood pressure by getting joined to the walls of the arteries. They also control the digestion of the food.
Muscle Contraction Mechanism
Here the main role is played by the myofilaments. During the process of muscle contraction the thick myosin myofilaments will come in contact with the thin myofilaments. The entire process follows there on, the contracted muscle will not only become shorten but also thicker. However the volume of the muscle will remain the same.
In muscle contraction, the sarcomeres can get shortened up to 60- 70 %. This however will depend upon the number of motor units involved in the process.
There is voluntary contraction of the muscles which also takes place and it is controlled by the central nervous system. This happens because of the signals which are moving inside the brain. The signals of the brain are sent to the motor neuron through the nervous system that in turn propels the muscle fibres. On the other hand, the involuntary muscles such as heart and the smooth muscles which are present in the gut and vascular system tend to contract owing to the activities going inside the brain unconsciously.