What Are Involuntary Muscles?

This question relates to the topic of biology of muscles. The body parts are moved by muscular contraction. Two types of muscles are found in the mammalian body; voluntary and involuntary muscles. Involuntary muscles are those muscles which are not under the control of the will. They are found in the alls of the alimentary canal, arteries and veins. Like the skeletal muscle, an involuntary muscle consists of numerous muscle fibers. Each muscle fiber is spindle shaped, thick in the middle and tapering gradually towards the ends. It has only a single nucleus in the cytoplasm. Cross striations are absent in these muscle fibres, hence they are called unstraited or smooth muscles. Unstraited muscles are capable of slow and sustained contractions.

Cardiac muscle is a special form of involuntary muscle. It occurs only in the walls of the heart. Cardiac muscle fibres are fairly short and have very faint cross striations. The fibers do not occur separately, but they branch and unite to form a branching network. Heart muscle can contract rhythmically without nervous stimulation. This can be noticed, when an animal or a man dies, even though this brain and nervous system has stopped working, the heart still beats rhythmically.

Involuntary muscles are not attached to bones usually your not aware that these muscles are working for example your involuntary muscles in your stomach contract and relax to mash and squeeze the food you eat