Question

Smooth muscle fibers are similar to cardiac and skeletal muscle fibers in that they all have the following except?

1) Striations
2) Actin and myosin filaments
3) Ability to contract
4) Involuntary control

Answer 1

Smooth muscle fibers do not have striations but have actin and myosin filaments. They can contract and are under involuntary control.

Step-by-step explanation:

Smooth muscle fibers do not have striations, which are visible patterns or stripes seen in skeletal and cardiac muscle fibers. Smooth muscle fibers are non-striated. However, they do have actin and myosin filaments, which are the contractile proteins responsible for muscle contraction. Smooth muscle fibers can contract and have the ability to shorten, similar to skeletal and cardiac muscle fibers. The main difference is that smooth muscle fibers are under involuntary control, while skeletal and cardiac muscle fibers can be voluntarily controlled.