ISSA Nutritionist Practice Exam

What are the three types of muscle found in the human body?

1. Skeletal, cardiac, and smooth

2. Skeletal, cardiac, and dense

3. Smooth, cardiac, and striated

4. Cardiac, skeletal, and involuntary

The correct answer is: Skeletal, cardiac, and smooth

The three types of muscle found in the human body are skeletal, cardiac, and smooth. Each type serves distinct functions and has unique characteristics. Skeletal muscle is striated and under voluntary control, meaning it can be consciously controlled to facilitate movement of the skeleton. This type of muscle is responsible for locomotion and is attached to bones via tendons. Cardiac muscle, found only in the heart, is also striated but operates involuntarily. This muscle type is specialized for continuous, rhythmic contractions to pump blood throughout the body. It has unique features, including intercalated discs that allow for synchronized contractions. Smooth muscle is non-striated and operates involuntarily as well. It is found in the walls of hollow organs, such as the intestines and blood vessels, and is responsible for controlling movements such as peristalsis in the digestive tract and regulating blood vessel diameter. The other options contain terms that either misrepresent the muscle types or mix irrelevant terminology. For example, "dense" does not refer to a recognized muscle type, "striated" is a common characteristic of some muscles but not a distinct type on its own, and "involuntary" describes a function rather than a specific type of muscle.