Kaplan Nursing Entrance Practice Exam

What type of muscle is primarily found in the gastrointestinal tract?

1. Skeletal muscle

2. Cardiac muscle

3. Smooth muscle

4. Striated muscle

The correct answer is: Smooth muscle

Smooth muscle is the correct choice because it is the primary type of muscle tissue found in the gastrointestinal tract. This type of muscle is involuntary and operates without conscious control, which is essential for the automated peristaltic movements that propel food through the digestive system. Smooth muscle cells are not striated, allowing for more uniform contractions and relaxation, which is important for the continuous and rhythmic movements necessary for digestion. Skeletal muscle, while being the type of muscle that contracts voluntarily and is associated with the movement of bones and joints, is not found in the walls of the gastrointestinal tract. Cardiac muscle is specialized for the heart and, like smooth muscle, is also involuntary. However, it is found exclusively in the heart and is not involved in the functions of the digestive system. Striated muscle refers to both skeletal and cardiac muscles, but since skeletal muscle does not play a role in the gastrointestinal tract, this option is not applicable in the context of this question. Thus, smooth muscle is uniquely suited for the functions required in the GI tract.