Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.

Striated (Skeletal) Muscle:**
– Structure: Comprised of long, multinucleated fibers exhibiting visible alternating dark and light bands (striations) due to the organized arrangement of contractile proteins (actin and myosin). Each fiber is cylindrical and striated.

– Location: Attached to bones by tendons. They facilitate voluntary movements like walking, running, and lifting weights, offering control over bodily actions.

Unstriated (Smooth) Muscle:
– Structure: Smooth muscles lack striations and possess spindle-shaped cells with a single nucleus. Their arrangement of actin and myosin filaments is irregular, giving a smooth appearance under a microscope.

– Location: Found in the walls of internal organs (like the digestive tract, blood vessels, bladder), respiratory passages, and other involuntary structures. They control involuntary functions such as peristalsis and organ contractions.

Cardiac Muscle:
– Structure: Cardiac muscle cells (cardiomyocytes) are striated, branched, and contain a single nucleus. They display intercalated discs with gap junctions and desmosomes, aiding in synchronized contractions and structural integrity.

– Location: Unique to the heart, forming the myocardium. Cardiac muscles are involuntary and responsible for pumping blood throughout the body via rhythmic contractions.

Summary of Differences:
– Structure: Striated muscles exhibit visible striations and multinucleated fibers, smooth muscles lack striations and have a single nucleus, while cardiac muscles have striations and intercalated discs with a single nucleus per cell.

– Location: Striated muscles are voluntary and attached to bones, smooth muscles are involuntary and present in internal organs, and cardiac muscles are also involuntary but exclusive to the heart, facilitating continuous blood circulation.

In essence, striated muscles allow voluntary movements, smooth muscles control involuntary functions in internal organs, and cardiac muscles maintain the heart’s involuntary pumping action, each tailored for specific roles in the body.