Q.The muscles attached to the bones are called
a. skeletal muscle
b. cardiac muscle
c. involuntary muscle
d. smooth muscles

Skeletal (voluntary) muscle is anchored to bone by a tendon and is organised as a nested hierarchy of connective-tissue-wrapped bundles: the whole muscle (wrapped in epimysium) is divided into fascicles (wrapped in perimysium), each fascicle made of individual muscle fibres (wrapped in endomysium).

Each muscle fibre is a single elongated, multinucleate cell whose plasma membrane is the sarcolemma and whose cytoplasm is the sarcoplasm, rich in glycosomes (stored glycogen), myoglobin (an oxygen-storing red pigment) and an extensive sarcoplasmic reticulum (which stores calcium). Hundreds to thousands of parallel myofibrils run the fibre's length, each showing a repeating pattern of dark A-bands and light I-bands that gives the whole fibre its striated appearance — the alternating bands are perfectly aligned across adjacent myofibrils, which is what makes the striping visible.

The repeating functional unit of this pattern is the sarcomere — the segment of myofibril between two successive Z-discs, containing a full A-band (with its paler central H-zone, bisected by the M-line) flanked by a half I-band on each side. Deep inward folds of the sarcolemma form T-tubules that carry the electrical signal for contraction rapidly into the fibre's interior.