Q. Voluntary muscles are present in:
NTA AbhyasNTA Abhyas 2020
Solution:
Striated muscle:
Location: The striated muscle is normally found attached to the bones in the head, trunk and limbs. Hence, it is called skeletal muscle. It is also found in the body wall, tongue, pharynx and at the beginning of the oesophagus. In a vertebrate body, it forms more than 80% of the soft tissues.
Structure:
(i) A number of muscle fibres run parallel to each other and are arranged in bundles called fascicule. The fascicule is bound together by connective tissue.
(ii) Each muscle fibre is about 40 mm in length.
(iii) Each muscle fibre is bounded by an elastic membrane called sarcolemma.
(iv) The sarcoplasm also contains a network of endoplasmic reticulum called sarcoplasmic reticulum.
(v) Each muscle fibre is made up of a large number of myofibrils.
(vi) Each myofibril shows alternate dark and light cross-bands due to actin and myosin filaments, the striations or strips. Hence, the name striated or striped muscle.
(vii) Striated muscle fibres can contract quickly. They undergo fatigue easily. So they are also called fatigue muscle.
(viii) The striated muscles can be moved according to the will of the animal. So they are also called voluntary muscle.
Location: The striated muscle is normally found attached to the bones in the head, trunk and limbs. Hence, it is called skeletal muscle. It is also found in the body wall, tongue, pharynx and at the beginning of the oesophagus. In a vertebrate body, it forms more than 80% of the soft tissues.
Structure:
(i) A number of muscle fibres run parallel to each other and are arranged in bundles called fascicule. The fascicule is bound together by connective tissue.
(ii) Each muscle fibre is about 40 mm in length.
(iii) Each muscle fibre is bounded by an elastic membrane called sarcolemma.
(iv) The sarcoplasm also contains a network of endoplasmic reticulum called sarcoplasmic reticulum.
(v) Each muscle fibre is made up of a large number of myofibrils.
(vi) Each myofibril shows alternate dark and light cross-bands due to actin and myosin filaments, the striations or strips. Hence, the name striated or striped muscle.
(vii) Striated muscle fibres can contract quickly. They undergo fatigue easily. So they are also called fatigue muscle.
(viii) The striated muscles can be moved according to the will of the animal. So they are also called voluntary muscle.