A nurse is teaching a class about skeletal muscles.
Which of the following should the nurse identify as a function of skeletal muscles?
A.
Skeletal muscles enable the heart to contract with each heartbeat
B.
Skeletal muscles enable the bladder to contract during voiding
C.
Skeletal muscles enable the bronchioles to dilate in the lungs
D.
Skeletal muscles enable a hand to contract and form a fist
E.
Skeletal muscles enable a hand to contract and form a fist
The Correct Answer and Explanation is:
The correct answer is D. Skeletal muscles enable a hand to contract and form a fist.
Explanation:
Skeletal muscles are one of the three types of muscle tissue in the human body, alongside cardiac and smooth muscles. They are primarily responsible for voluntary movements, which are under conscious control. This type of muscle tissue is attached to bones via tendons, and its contraction facilitates movement of the skeletal system.
- Function of Skeletal Muscles:
- Voluntary Movement: Skeletal muscles enable various voluntary movements by contracting and pulling on bones. For example, when you make a fist, the skeletal muscles in your forearm contract, pulling the tendons attached to your hand bones. This contraction bends the fingers and forms a fist. This voluntary control allows for precise and intentional movements.
- Comparison to Other Options:
- A. Skeletal muscles enable the heart to contract with each heartbeat: This statement is incorrect because the heart’s contractions are facilitated by cardiac muscles, not skeletal muscles. Cardiac muscle is a specialized type of muscle tissue found only in the heart.
- B. Skeletal muscles enable the bladder to contract during voiding: This is incorrect because the bladder’s contraction is controlled by smooth muscle, not skeletal muscle. Smooth muscle is responsible for involuntary movements in various internal organs.
- C. Skeletal muscles enable the bronchioles to dilate in the lungs: The dilation and constriction of bronchioles are regulated by smooth muscle, not skeletal muscle. Smooth muscle controls the involuntary movements of the respiratory passages.
- E. Skeletal muscles enable a hand to contract and form a fist: This option is the same as D and correctly describes the function of skeletal muscles. It accurately reflects how skeletal muscles enable voluntary movements such as making a fist.
In summary, skeletal muscles play a crucial role in voluntary movements by contracting and exerting force on the bones they are attached to. This function is essential for activities ranging from simple gestures, like forming a fist, to more complex motor skills.