The muscular system consists of skeletal,smooth, and cardiac muscle and associated connective tissues. Skeletal, orvoluntary, muscle has a connective tissue sheathing that becomes narrowed as atendon to attach the muscle to a bony prominence. Smooth muscle is involuntaryand generally has less associated connective tissue than skeletal muscle.
Cardiac muscle is involuntary and is found exclusively in the heart.
The threemuscle subtypes have quite different histological appearances and verydifferent functions, even though the general function of muscle is movement ofbody parts. Applications Toxins produced by certain bacteria canaffect muscle cells, and hence bodily activity. Clostridium tetani producesa tetanus toxin that inhibits normal breakdown and recycling of theneurotransmitter that stimulates muscle cells. Some parasitic worm life cycle stages encystin muscle tissue, causing destructive or painful muscle disease. The porktapeworm, Taenia solium, lives not only in the human intestine, but can spreadthroughout the body and encyst in many human organs, including muscle tissue.