Skeletal muscle/striated muscle
Striated muscles are those muscles having cross striations, therefore called striated muscles. They are attached to bones through tendons.
Their activities are in our control, which means they are voluntary in action and so these types of muscles are known as voluntary muscles.
Unstriated muscles are those muscles that do not show cross striations, their cells are connected through gap junction, look smooth in appearance, so known as smooth muscles.
The activities of the smooth muscle fiber are not under our control, which means these muscles are involuntary in action, therefore, called involuntary muscles.
These muscles are striated and involuntary. Have rich blood supply is found in these muscles because of more mitochondria and have the intercalated disc or septa.
These muscles are similar to skeletal muscle in structure and similar to smooth muscle in function.
|S.No.||Condition||Striped or striated muscle||Unstriped or unstriated muscle or non-striated||Cardiac muscle|
|1.||Location||These muscle fibers are present in the upper and lower limbs, biceps, triceps, deltoid, …||Ciliary muscle of the eye (Iris), urinary bladder, urinogenital tract, arrector pili muscle in the dermis of the skin, intestinal muscle, abdominal muscle, internal organs, …||Found in the heart wall|
|2.||Shape||Long and cylindrical in shaped||Short and spindle-shaped||Long and cylindrical in shape|
|3.||Branching in fiber||Unbranched||Unbranched||Branched|
|4.||Nucleus in cytoplasm||Multi-nucleated cytoplasm (Syncytium)||Uninucleated cytoplasm||Uninucleated cytoplasm|
|5.||Striations (dark + light bands)||Present||Absent||Present|
|6.||Division||Oblique bridge and intercalated disc absent||Absent||Present|
|7.||Regulated by||Central nervous system (CNS)||Autonomic nervous system (ANS)||Both CNS and ANS|
|8.||Blood supply||Adequate||Less||Rich blood supply|
|9.||Fatigue||Fast get fatigue||Don’t get fatigued||Never get fatigued|
|10.||Contraction speed||Fastest||Slowest but for a long period||Fast|
|12.||Image (credit: sciencelearn.org.nz)|
Skeletal and smooth muscles are further divided into red and white muscle fibre.