Muscles are an integral part of our body. They are classified into three types depending on function and location. For this article, we will focus on the difference between smooth and skeletal muscles.
Smooth muscles are involuntary non-striated muscles that can be found along the walls of hollow internal organs. They function in contraction of the internal organs.
Skeletal muscles are involuntary striated muscles that are attached to bone through tendons or to each other via aponeurosis. Their main function is for body movement.
|Smooth Muscles||Skeletal Muscles|
|Sustained slow, rhythmic contraction||Rapid contraction but tire quickly|
|Spindle-shaped muscle||No branching|
|Cells are uninucleated||Cells are multinucleated|
|Lining of internal organs||Attached to bone via tendon or each other via aponeurosis|
|Contraction of internal organs||Body movement|
Let us compare the two in terms of control, rate of contraction, location, and function.
- Smooth muscles are involuntary muscles; the individual has no control over their contraction and relaxation. Skeletal muscles, however, are voluntary muscles; one has complete control over their contraction and relaxation.
- Smooth muscles contract more slowly. The rate of contraction of skeletal muscles is fast but they can tire easily.
- Smooth muscles are non-striated like cardiac muscles, while skeletal muscles are striated.
- Each smooth muscle is spindle-shaped; skeletal muscles have no branches.
- When seen under the microscope, smooth muscle cells have only one nucleus located at the center. Skeletal muscle cells have more than one nucleus located along the whole tissue.
- Smooth muscles can be found along the lining of hollow internal organs like the stomach, intestines, bladder, uterus, blood vessels, and a lot more. Basically they line all hollow organs. On the other hand, skeletal muscles can be found attached to bone. Examples of skeletal muscles include biceps and triceps found on the arms.
- Smooth muscles function in the contraction of internal organs allowing substances inside to move, while the purpose of skeletal muscles is body movement.
Watching the following video will help demonstrate the difference between the three types of muscles: