ATI RN
Muscular System Test Questions Questions
Question 1 of 5
What is the main function of the temporal bone?
Correct Answer: B
Rationale: The temporal bone houses the middle ear (e.g., ossicles), facilitating hearing/balance, via its petrous portion. It protects the brain partially, but ear housing is primary. Cheekbone is zygomatic, spine support is vertebral. Temporal's auditory role, per skull, makes 'b' correct.
Question 2 of 5
Cancer cells can be characterized as 'generic' cells that perform no specialized body function. Thus cancer cells lack
Correct Answer: A
Rationale: Cancer cells lack differentiation, remaining unspecialized and 'generic,' unlike normal cells (e.g., liver cells) with specific roles, driving uncontrolled growth. They retain reproduction , often excessively, and responsiveness to some signals, not both . Loss of differentiation, a hallmark of cancer per pathology, makes 'a' correct.
Question 3 of 5
The heart is within the
Correct Answer: B
Rationale: The heart lies in the mediastinum, a central thoracic cavity subdivision between the lungs, housing heart and vessels. Cranial cavity holds the brain, posterior/dorsal includes spinal/brain cavities not heart. Not all only mediastinum fits. Its thoracic centrality, per anatomy, makes 'b' correct.
Question 4 of 5
Which disease results in muscle weakness due to a lack of neurotransmitter receptors?
Correct Answer: C
Rationale: Myasthenia gravis causes muscle weakness by reducing acetylcholine receptors at the neuromuscular junction. Autoantibodies attack these receptors, impairing signal transmission from motor neurons to skeletal muscle, leading to fatigue, especially in facial and limb muscles. Muscle dystrophy involves progressive fiber degeneration, not receptor loss. Intermittent claudication stems from vascular insufficiency, weakening muscles via oxygen deprivation, not neurotransmission. Tetanus, from bacterial toxin, causes rigid contractions, not weakness, by overstimulating neurons. Fibromyositis (likely fibromyalgia) involves pain and stiffness, not receptor deficits. In myasthenia gravis, the postsynaptic membrane's receptor scarcity confirmed by immunological and electromyographic studies disrupts voluntary movement, often relieved by acetylcholinesterase inhibitors boosting acetylcholine. This autoimmune mechanism contrasts with structural or infectious muscle disorders, highlighting a specific synaptic failure. Clinical data show receptor density dropping 70-90% in affected junctions, underscoring its unique pathophysiology among neuromuscular diseases.
Question 5 of 5
The nurse is discussing actions that can be taken to best prevent osteoporosis with a patient. The nurse s teaching should include:
Correct Answer: C
Rationale: Osteoporosis prevention relies heavily on maintaining bone density and strength over time. Regular physical activity, especially weight-bearing exercises like walking or strength training, stimulates bone formation and slows bone loss, making it a cornerstone of prevention. While a balanced diet is essential for overall health, it alone doesn't target bone health unless it specifically includes adequate calcium and vitamin D. Taking extra calcium supplements might help if dietary intake is insufficient, but it's not the most proactive or comprehensive approach without exercise. Consuming daily milk products provides calcium, but this is only one piece of the puzzle and doesn't address the mechanical stress on bones that exercise provides. Exercise throughout life stands out because it directly impacts bone remodeling and resilience, reducing the risk of fractures as one ages, unlike the other options which are either narrower in scope or less effective independently.