Muscular System of Human BodyGeneral Knowledge » Science »
Muscular System of Human Body
Muscles specialized to contraction are of 3 types :
- Unstriated and
Striated Muscles are also called Skeletal Muscles. These muscles are mostly attached to bones by tendons and takes part in voluntary movements under conscious control of brain.
Therefore they are called voluntary muscles. Each muscle fibre shows dark and light striations and is covered by a sheath, the sarcolemma.
Its cytoplasm is called sarcoplasm in which are present large number of contractile myofibrils. Myofibrils are made up of thick myosin and thin actin filaments. They are present in limbs, tongue, pharynx, etc.
These smooth muscles are involuntary muscles. Functionally they are of two types – single unit and multi unit.
Single unit smooth muscles are present in urinary bladder and gastro intestinal tract. Multi unit smooth muscles are present in walls of large blood vessels.
They are involuntary, striated and non fatigued fibres which are found in the wall of heart where they form myocardium. They generate their own wave of excitation.