ATI RN
Multiple Choice Questions Muscular System Questions
Question 1 of 5
A collection of similar tissues that performs a specific function is an
Correct Answer: A
Rationale: An organ, like the stomach, is a collection of similar tissues (e.g., muscle, epithelium) working together for a specific function (digestion). An organelle is a cellular structure (e.g., mitochondria), not tissues. An organism is the whole living entity. An organ system like the digestive system includes multiple organs, broader than one. The organ's tissue-based, functional unity, per anatomical hierarchy, makes 'a' correct.
Question 2 of 5
Which muscle type(s) can be accurately described as visceral, nonstriated and involuntary?
Correct Answer: A
Rationale: Smooth muscle, found in visceral organs like the stomach and blood vessels, lacks striations due to its unorganized actin and myosin arrangement, unlike the sarcomeres of skeletal and cardiac muscle. It operates involuntarily, controlled by the autonomic nervous system, enabling functions like peristalsis without conscious effort. Skeletal muscle, attached to bones, is striated and voluntary, governed by the somatic nervous system for deliberate movements. Cardiac muscle, in the heart, is striated with intercalated discs and involuntary, but its rhythmic contractions distinguish it from smooth muscle's slower, sustained actions. Visceral typically denotes internal organs, aligning with smooth muscle's role, not cardiac or skeletal. Histologically, smooth muscle's spindle-shaped, uninucleate cells contrast with skeletal's multinucleate fibers and cardiac's branched structure. Physiological texts emphasize smooth muscle's unique calcium regulation via calmodulin, not troponin, reinforcing its distinct involuntary nature. This specificity clarifies why only smooth muscle fits all three descriptors, avoiding overlap with striated types.
Question 3 of 5
A continuous, sustained contraction that shows no relaxation is called
Correct Answer: A
Rationale: Complete tetanus occurs when rapid, repeated stimuli fuse muscle contractions into a sustained, maximal force with no relaxation phase. High-frequency nerve impulses (e.g., 50-100 Hz in humans) keep calcium levels elevated in the sarcoplasm, preventing actin-myosin cross-bridges from disengaging. A twitch is a single, brief contraction-relaxation cycle from one stimulus, lasting 20-100 ms. Incomplete tetanus, with slightly slower stimuli, shows partial relaxation between peaks. Wave summation adds force as stimuli increase before full relaxation, but retains distinct twitches. Treppe enhances force gradually without fusion. Complete tetanus, observable in lab settings or extreme exertion, maximizes tension up to 4-5 times twitch force reflecting sustained motor unit recruitment. Electromyography distinguishes its smooth plateau from twitch's spike or incomplete tetanus's ripples. Physiologically, it mimics intense efforts like lifting heavy loads, contrasting with transient or stepped responses, highlighting muscle's capacity for prolonged output under continuous stimulation.
Question 4 of 5
The nurse informs the patient that the frequency of range-of-motion (ROM) exercises should be:
Correct Answer: C
Rationale: Range-of-motion exercises need to be frequent enough to maintain joint mobility and prevent stiffness, especially in patients at risk of contractures. Performing them 3 to 4 times a day ensures joints are moved through their full range multiple times, counteracting the effects of immobility without overtaxing the patient. Once a day is insufficient, as stiffness can develop within hours of inactivity. Twice daily (morning and afternoon) improves on that but may still allow periods of prolonged immobility. Four to six times might be ideal for severe cases but could exhaust the patient or staff resources unnecessarily. The 3 to 4 times recommendation balances efficacy and practicality, promoting flexibility and circulation while fitting into a realistic care schedule.
Question 5 of 5
When an 88-year-old patient enters the room for her health assessment, she walks with tiny steps, her shoulders are rounded and hunched, and her arms are crossed in front of her with her hands tucked in her armpits. Which response by the nurse is most appropriate?
Correct Answer: A
Rationale: The patient's posture tiny steps, hunched shoulders, and arms crossed with hands tucked suggests she might be cold, as this is a common way to conserve heat. Asking about coldness directly addresses a likely physical cause, opening a dialogue to assess further. Stomach pain might cause hunching but not typically arm-crossing or tiny steps. Shoe size could affect gait, but the full posture doesn't align with that alone. Asking if she always walks like this assumes a chronic issue without exploring immediate discomfort. The coldness question is most appropriate, as it's empathetic, specific to the observed behavior, and prompts clarification, guiding the nurse to tailor care effectively.