Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

What type of muscle is referred to as involuntary muscle found inside many internal organs?

1. Cardiac muscle

2. Skeletal muscle

3. Smooth muscle

4. Striated muscle

The correct answer is: Smooth muscle

Smooth muscle is indeed the type of muscle referred to as involuntary muscle found inside many internal organs. This muscle type functions automatically and is not under conscious control, which distinguishes it from skeletal muscle that is voluntary and allows for movement of the skeleton. Smooth muscle is primarily located in the walls of hollow organs such as the intestines, blood vessels, bladder, and the uterus. Its role is crucial for involuntary actions such as peristalsis in the digestive tract (the wave-like motion that moves food along) and regulating blood vessel diameter to control blood flow and pressure. Cardiac muscle, while also involuntary, is specific to the heart and has unique features that distinguish it from smooth muscle. Skeletal muscle, on the other hand, is striated and primarily responsible for voluntary movements of the body. Striated muscle is a broader term that includes both skeletal muscle and cardiac muscle but does not apply to smooth muscle, which is non-striated. Understanding these distinctions helps clarify why smooth muscle is the correct answer, as it specifically refers to the involuntary muscle type found within many of the body's internal organs.