ATI RN
Multiple Choice Questions on Muscular System Questions
Question 1 of 5
The body system responsible for structural support and movement is the
Correct Answer: D
Rationale: The skeletal system provides structural support via bones and enables movement by anchoring muscles at joints (e.g., femur in walking). The cardiovascular system circulates blood, not support/movement. The endocrine system regulates via hormones. The muscular system moves but relies on skeletal framework. Skeletal system's foundational role, per body systems, makes 'd' correct.
Question 2 of 5
The connective tissue covering of a fascicle is known as
Correct Answer: B
Rationale: Muscle tissue is organized hierarchically, with fascicles bundles of muscle fibers encased by perimysium, a connective tissue sheath. This layer provides structural support, houses blood vessels and nerves, and separates fascicles within the muscle, facilitating coordinated contraction. Endomysium surrounds individual muscle fibers, a finer layer penetrating within fascicles. Epimysium envelops the entire muscle, integrating with tendons dense connective tissue linking muscle to bone. Deep fascia, a broader sheet, encases muscle groups externally, not specific fascicles. The perimysium's role is critical: its collagen and elastin composition balances flexibility and strength, protecting fascicles during stretching or contraction. Histological analysis reveals its thicker, more organized structure compared to endomysium's reticular fibers, distinguishing it from tendons' load-bearing function or epimysium's holistic coverage. Misidentifying these layers could obscure muscle organization, but perimysium's fascicle-specific wrapping is evident in dissections and biomechanical studies, underscoring its intermediate position in muscle anatomy.
Question 3 of 5
Which statement best represents skeletal muscle?
Correct Answer: D
Rationale: Skeletal muscle fibers are multinucleate, formed by myoblast fusion during development, hosting dozens of nuclei per cell for protein synthesis supporting contraction. Unlike cardiac muscle, which contracts rhythmically via an intrinsic pacemaker (sinoatrial node), skeletal muscle lacks automaticity, relying on somatic motor neuron signals for voluntary action. Rhythmic contractions occur in cardiac muscle, not skeletal, though skeletal can sustain rhythmic activity (e.g., shivering) if neurally driven, not self-initiated. Uninucleate cells typify smooth muscle, not skeletal. The 'or' phrasing suggests potential for rhythmicity or pacemaker presence, but skeletal muscle's defining trait is voluntary, multinucleate structure without inherent rhythmicity. Histology confirms its striated, multinucleate fibers, contrasting with cardiac's pacemaker-driven rhythm or smooth's uninucleate spontaneity. Physiology texts emphasize this dependency on external innervation, distinguishing skeletal muscle's control and structure in locomotion.
Question 4 of 5
The physician has prescribed isometric exercises for a patient. The patient asks the nurse how these exercises work. The nurse uses an example to explain the physiology of isometric exercises, which is:
Correct Answer: A
Rationale: Isometric exercises involve muscle contraction without joint movement, building strength by maintaining tension against resistance. Flexing the lower arm while resisting with the other hand exemplifies this: the biceps contract but the elbow angle stays fixed, engaging muscle fibers statically. Pulling knees to the chest involves dynamic movement, not isometric principles. Forcefully flexing the neck to touch the chin implies motion, not static tension. Flexing toes upward while lying flat also involves joint movement, missing the isometric focus. The arm example clearly demonstrates how muscles work against an opposing force without changing position, aligning with the physiology of isometric training to enhance strength in a targeted, controlled way.
Question 5 of 5
The nurse is changing the position of a person with flaccid paralysis. The priority action will be:
Correct Answer: A
Rationale: Flaccid paralysis causes muscle limpness, increasing the risk of joint stiffness or deformity from prolonged immobility. Changing joint position is the priority to prevent contractures and maintain alignment, using careful support to avoid strain. Not using a footboard might prevent footdrop in some cases, but it's secondary to overall joint care. Moving only side to side limits flexibility and risks pressure sores, ignoring full-body needs. Avoiding pillows dismisses a tool for support, which isn't the issue positioning is. Adjusting joints takes precedence, as it directly addresses the paralysis-related risk of fixed postures, ensuring long-term mobility and comfort.