ATI RN
Questions About the Muscular System Questions
Question 1 of 5
Which of the following specialties might focus on studying all of the structures of the ankle and foot?
Correct Answer: C
Rationale: Regional anatomy studies all structures (bones, muscles, nerves, etc.) within a specific body area, like the ankle and foot, making it ideal for a comprehensive focus on that region's anatomy. Microscopic anatomy examines cells/tissues at a cellular level, not gross structures. Muscle anatomy is too narrow, focusing only on muscles, not all ankle/foot components. Systemic anatomy studies body systems (e.g., skeletal) across the whole body, not one region. Regional anatomy's localized, all-inclusive approach, per anatomical study methods, makes 'c' the correct specialty.
Question 2 of 5
Which of the following imaging studies can be used most safely during pregnancy?
Correct Answer: C
Rationale: Ultrasounds use sound waves, safe for pregnancy, avoiding radiation risks to the fetus, commonly monitoring development. CT and X-rays emit ionizing radiation, harmful. PET uses radioactive tracers, also risky. Ultrasound's non-invasive safety, per medical practice, makes 'c' correct.
Question 3 of 5
Which statement best reflects slow, oxidative skeletal-muscle fibers?
Correct Answer: A
Rationale: Slow, oxidative skeletal muscle fibers (Type I) excel in endurance, resisting fatigue due to high mitochondrial density and oxidative enzyme activity, relying on aerobic metabolism. Their red color stems from abundant myoglobin, an oxygen-storing protein, and rich capillary networks, supporting sustained activity like posture maintenance or marathon running. Fast fibers (Type II), white or pale, depend on glycolysis, fatiguing quickly in bursts like sprinting. Pink fibers, an intermediate type (Type IIa), blend traits but aren't slow or maximally enduring. Histochemical staining reveals Type I's oxidative capacity up to 50% more mitochondria than fast fibers and their myoglobin content, absorbing red light. White fibers, low in myoglobin, fatigue rapidly under anaerobic conditions. Red fast fibers exist but prioritize speed over endurance. Exercise science links these traits to function: slow fibers' fatigue resistance suits long-term effort, contrasting with fast fibers' power, making their slow, red profile distinct in muscle classification.
Question 4 of 5
The nurse adds interventions for range-of-motion (ROM) and isometric exercises for the new patient with a stroke because the nurse is aware that contracture formation begins as early as day(s) of immobilization.
Correct Answer: C
Rationale: Contractures begin forming when muscles and joints remain immobile for an extended period, with evidence suggesting this process can start within a few days. In stroke patients, paralysis or weakness often leads to immobility, and research indicates that muscle shortening and joint stiffness can emerge as early as 3 days without movement. One day is too short for significant changes, as tissues need sustained inactivity to adapt pathologically. Two days may show minor stiffness, but 3 days aligns with clinical observations of early contracture onset. Ten days is far too long, as by then contractures would likely be well-established, not just beginning. ROM and isometric exercises are thus introduced early to maintain flexibility and muscle tone, preventing this rapid complication in stroke recovery.
Question 5 of 5
When a 90-year-old patient says, My old bones are just about done in, the nurse reminds him that his bones are being constantly renewed through the action of:
Correct Answer: A
Rationale: Bone renewal is an ongoing process called remodeling, driven by osteoblasts, cells that build new bone by depositing mineralized matrix. This counters the patient's notion of bones wearing out, as osteoblasts work with osteoclasts (which break down bone) to maintain skeletal health, even in old age. Stem cells contribute broadly to tissue repair but aren't specific to bone renewal. Free calcium ions are raw materials, not active agents. Phosphorus and vitamin D support mineralization, but osteoblasts execute the process. Highlighting osteoblasts reassures the patient that regeneration persists, emphasizing the dynamic nature of bone tissue over passive nutrient roles.