Which of the following muscle types is primarily under voluntary control?

Appeared in: HSSC Staff Nurse - 2015

Explanation

Skeletal muscles are responsible for the movement of the skeleton and are under conscious, or voluntary, control.
They are innervated by the somatic nervous system, which allows for direct control from the brain to initiate movement.
Examples of voluntary actions include walking, lifting an object, or speaking.
Under a microscope, skeletal muscle fibers appear striated (striped).

Option A: Cardiac muscle, found in the heart, is involuntary. Its rhythmic contractions are automatic and essential for pumping blood, not under conscious control.
Option B: Smooth muscle, found in the walls of internal organs like the intestines and blood vessels, is involuntary. It controls processes like digestion and blood pressure regulation without conscious effort.
Option D: Visceral muscle is another term for smooth muscle. Therefore, it is also an involuntary muscle type, making it an incorrect answer for the same reasons as smooth muscle.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Types of muscle tissue and their control mechanisms as background academic context rather than a clinical decision trigger.
Understanding the difference between voluntary and involuntary muscle control is fundamental in nursing. It helps in assessing neuromuscular disorders, effects of anesthesia, and the action of various medications.
For example, conditions like spinal cord injuries or strokes can disrupt the nerve signals to skeletal muscles, leading to paralysis or loss of voluntary movement.
Medications like beta-blockers act on the involuntary cardiac muscle to control heart rate and blood pressure.

How to Approach the Question

First, identify the key term in the question: 'voluntary control'.
Next, recall the three main types of muscle tissue: skeletal, cardiac, and smooth.
Consider the primary function and control mechanism of each type.
Skeletal muscle is associated with moving bones, an action you can consciously control.
Cardiac muscle is in the heart and beats automatically (involuntary).
Smooth (or visceral) muscle is in organs and blood vessels, functioning automatically (involuntary).

Concept Tested & Keywords

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E6 Physiology Ganong 27e Vol 2 Part 3 p. 78-80

E6 Anatomy Applied Ashalatha 4e p. 317-319

E6 Nursing Fundamentals Taylor p. 307-309

Practise the full HSSC Staff Nurse - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.