ATI RN
Questions About the Muscular System Questions
Question 1 of 5
C.J. is stuck in her car during a bitterly cold blizzard. Her body responds to the cold by
Correct Answer: C
Rationale: In cold, the body breaks down stored energy (e.g., glycogen, fat) via metabolism to generate heat (thermogenesis), maintaining core temperature. Blood to hands/feet decreases (vasoconstriction) to save heat. Lethargy isn't primary shivering is. Blood oxygen doesn't spike, it's steady. Energy breakdown, per thermoregulation, makes 'c' correct.
Question 2 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 3 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 4 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.
Question 5 of 5
A patient with osteoporosis calls the nurse in the doctor s office to report that she has forgotten to take her weekly bisphosphonate (alendronate [Fosamax]) for 2 days past the weekly time. The nurse should advise the patient to:
Correct Answer: C
Rationale: Bisphosphonates like alendronate are taken weekly to slow bone loss in osteoporosis, with strict timing to maximize absorption and minimize side effects. Missing it by 2 days means taking it late could overlap with the next dose, risking irritation or reduced efficacy. Taking it now is tempting but disrupts the schedule. Two doses 3 days apart or doubling up now with a snack (which impairs absorption) violate dosing guidelines, potentially causing esophageal harm. Skipping this week and resuming next week maintains the regimen's consistency and safety, as the drug's long-acting nature means one missed dose won't drastically affect treatment, making it the best advice for adherence and health.