Muscular System Histology: TEAS Practice Question with Answer & Explanation

Understanding Muscle Tissue Types and Functions

To answer this question correctly for the TEAS 7 Science section, you must distinguish between the three primary types of muscle tissue in the human body: Skeletal, Cardiac, and Smooth.

The process described in the question—moving a bolus of food through the digestive tract—is called peristalsis. This is an involuntary process, meaning it happens without our conscious control.

Why Smooth Muscle is Correct

Smooth muscle is the correct answer because it is specifically designed for slow, sustained, and involuntary contractions. It is found in the walls of hollow internal organs such as the esophagus, stomach, intestines, bladder, and blood vessels. Unlike skeletal muscle, smooth muscle is non-striated (it lacks the "striped" appearance under a microscope) and is governed by the autonomic nervous system.

Why the Other Options are Incorrect

• A) Skeletal muscle: This tissue is mostly involved in voluntary movement (like walking or lifting weights). It is attached to bones by tendons. While the very top of the esophagus contains some skeletal muscle to initiate swallowing, the rhythmic, wave-like movement (peristalsis) throughout the digestive tract is the hallmark of smooth muscle.
• C) Cardiac muscle: This is a highly specialized type of muscle found only in the heart. It is striated like skeletal muscle but involuntary like smooth muscle. Its sole job is to pump blood, not move food.
• D) Voluntary muscle: This is another term for skeletal muscle. Since you cannot consciously control the movement of food once it passes the back of your throat, this cannot be the correct answer.

TEAS Concept: Muscle Classification

The TEAS exam frequently tests your ability to match a tissue type with its location and function.

• Skeletal: Striated, Multinucleated, Voluntary. (Biceps, Hamstrings).
• Smooth: Non-striated, Spindle-shaped, Involuntary. (Digestive tract, Arteries).
• Cardiac: Striated, Branched, Intercalated discs, Involuntary. (Heart only).

Memory Tip

Remember "Smooth moves." Smooth muscle is responsible for the "moving" of substances through your internal "tubes" (digestive tract, blood vessels, etc.) without you having to think about it!