Question

The muscular contraction in which the tension of muscle increases sharply, length of muscle remain the same and so mechanical work is done called as
A. Tetanus
B. Isotonic contraction
C. Isometric contraction
D. Twitch.

Answer 1

This kind of contraction produces force by modifying the length of the muscle and it may be concentric contractions or eccentric contractions. Holding the dumbbell or a large book in a constant position rather than actively moving upward or downward is an example of this type of muscular contraction.

Complete answer:
To answer this question, first, we need to know about muscle contraction. Muscle contraction is the starting of tension-generating sites with inside muscle fibers. Muscle contraction does not always define muscle shortening because muscle tension can be developed without modifying in muscle length, like holding a heavy book or a dumbbell at the constant position.
Now, let us find the solution from the option.
Tetanus is a severe disease that occurs by a bacterial toxin that affects the nervous system, causing painful muscle contractions.
Isotonic contractions control constant tension in the muscle as the muscle modifies length. This can happen only when a muscle's maximum contraction force exceeds the net weight on the muscle.
Isometric contraction, is one in which the muscle is activated, but instead of being allowed to lengthen or shorten, it is held at a constant length
Muscle twitching includes small muscle contractions in the body.

Thus, the correct option is B. i.e. isotonic contraction.

Note: Muscle fiber produces tension via the act of myosin and actin cross-link cycling. The muscle may lengthen, shorten, or remain the similar under tension. Although the word contraction defines shortening, when defining it to the muscular system, which means that muscle fibers produce tension with the support of motor neurons. Different kinds of muscle contractions happen and they are referred to by the modification in the length of the muscle by the period of contraction.