Biology · Locomotion and Movement · NEET
Cardiac muscle IS striated. Under the microscope it shows the same cross-bands (light and dark stripes) as skeletal muscle. This confuses students because striated muscle is usually voluntary, but cardiac muscle is the exception: it is striated AND involuntary. NCERT (Ch 17) states plainly: based on appearance, cardiac muscles are striated.
Because 'striated' describes only its appearance (the banding pattern), while 'voluntary vs involuntary' describes control. Skeletal muscle is striated AND voluntary. Cardiac muscle is striated BUT involuntary, because the nervous system does not directly control its beating. The heart is myogenic, the beat starts inside the cardiac muscle (nodal tissue), so you cannot start or stop your heartbeat by will.
Intercalated discs are special junctions that join adjacent cardiac muscle cells end-to-end. They are found ONLY in cardiac muscle. They let cells communicate and contract together as one unit. NEET loves to put 'intercalated discs' as a wrong option for smooth muscle, remember discs = cardiac only.
Cardiac muscle fibres are BRANCHED. Many cardiac muscle cells assemble in a branching pattern and join at intercalated discs. This is a key difference from skeletal muscle, whose long cylindrical fibres are unbranched. In a NEET figure, 'striated + branched fibres joined end-to-end' = cardiac muscle.
Cardiac muscle is found ONLY in the wall of the heart (myocardium). It is not present in blood vessels, the stomach, or intestine, those have smooth (visceral) muscle. So if a location like 'stomach' or 'blood vessel' is paired with cardiac muscle, that pairing is wrong.
Three types of muscle tissue are shown as (a), (b) and (c): (a) Long, parallel, cylindrical striated fibres with peripheral nuclei; (b) Spindle-shaped non-striated cells with a single central nucleus; (c) Striated, branched fibres joined end-to-end with central nuclei. Identify the correct matching pair with location:
Which of the following statements wrongly represents the nature of smooth muscle?
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Cardiac muscle is striated (has cross-bands), branched (fibres join end-to-end at intercalated discs), and involuntary (not under nervous control; the heart is myogenic). It is found only in the heart.
Yes. Intercalated discs are junctions found only in cardiac muscle. They join adjacent cardiac cells so they contract together. This is a favourite NEET distractor placed under smooth muscle options.
Cardiac muscle is involuntary. The nervous system does not directly control the heartbeat; the beat originates within the cardiac muscle itself (myogenic), so it keeps beating rhythmically on its own.
Both are striated, but cardiac muscle is branched, involuntary, has intercalated discs, and is found only in the heart, while skeletal muscle is unbranched, voluntary, has no intercalated discs, and is attached to bones. See the concept page on the difference between skeletal and cardiac muscle.
Because its contraction (heartbeat) originates within the muscle itself (from nodal tissue), not from an outside nerve signal. This is why a frog's heart continues to beat for some time even after removal from the body.
