Why are voluntary muscles also called skeletal muscles? Give an example of a skeletal muscle.
Answers
Explanation:
Voluntary means done out of free will or by choice. Voluntary muscles are also often called skeletal muscles (because all of the muscles attached to the skeleton are voluntary muscles) or striated muscles (because the muscle fibers make them look striated, or stripy).
Voluntary muscles are the muscles that are under conscious control and can be controlled at force or we can decide when to use them. They are also termed skeletal muscles as they are seen attached to the bones. Voluntary muscles are the reasons for the movement of body parts and locomotion. They are made with muscle fibres that are multinucleated cells with nuclei situated towards the edge of the cells. The muscle fibre has a cell membrane which is known as sarcolemma. The muscle fibres are set as one in a bundle to form the muscle. The power of voluntary muscles can be improved by exercising regularly.
Involuntary Muscles:
Involuntary muscles are also known as smooth muscles. They are the muscles in the human body that act without mindful control or cannot be controlled at our desire. They are generally controlled by the autonomic nervous system in the body. As a result, the involuntary muscles include all the muscles whose working is not affected by voluntary nerve activity.
The involuntary muscles are generally spindle-shaped and have a single centrally located nucleus. They are generally visceral and because of this they are mostly found in the walls of hollow organs such as the stomach, intestine, urinary bladder, uterus, etc. involuntary muscles are responsible for the movement of food in the alimentary canal and the contraction of the uterus during labour or childbirth and controlling the internal diameter of the blood vessels. Cardiac muscles also have involuntary muscles that maintain the blood circulation all through the body by maintaining the heartbeat.
Voluntary muscles are also known as Striated muscles and are the skeletal muscles. The reason behind why they are called voluntary muscles is that their action is under the control of the somatic nervous system and their movement can be controlled by us not like as in the case of involuntary muscles. The muscle fibres of striated muscles or the voluntary muscles are multinucleated and cylindrical. These muscles are fond of the bones and tendons and are the important reasons for the movements of the skeleton. The striated muscles also comprise longitudinal and cross striations.