ATI RN
Multiple Choice Questions Muscular System Questions
Question 1 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 2 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.
Question 3 of 5
The patient in a long arm cast (from below the shoulder to the wrist, with a 90-degree elbow flexion) complains of a burning sensation over the elbow. The nurse s initial intervention should be:
Correct Answer: A
Rationale: A burning sensation over the elbow in a cast suggests pressure or irritation, possibly from swelling or a tight fit. Elevating the arm on pillows is the initial step, as it reduces swelling by improving venous return, potentially relieving pressure on the elbow without invasive action. Checking support is useful but secondary, as elevation addresses the immediate cause. Notifying the charge nurse assumes a pressure ulcer without assessment, which is premature. Cutting a window is a last resort, requiring medical orders. Elevation is a safe, effective first response, tackling the likely swelling-related discomfort while preserving the cast's integrity for further evaluation.
Question 4 of 5
A group of skeletal muscles, their associated blood vessels, and associated nerves with a common function.
Correct Answer: A
Rationale: In anatomy, a compartment refers to a group of skeletal muscles along with their associated blood vessels and nerves that work together to perform a specific function. This term is commonly used to describe the organization of muscles in the limbs, such as the anterior or posterior compartments of the leg or forearm. These compartments are separated by fascia, which helps coordinate movement and maintain structural integrity. The anal triangle is a specific region of the pelvic floor, not a muscle group with a common function. The diaphragm is a single muscle involved in respiration, not a group of muscles. An aponeurosis is a broad, flat tendon-like structure that connects muscles to bones or other muscles, but it does not encompass a group of muscles with their blood vessels and nerves. Therefore, compartment is the most accurate term for this definition, as it aligns with the anatomical description of muscle organization.
Question 5 of 5
An injection of fluid directed into a muscle.
Correct Answer: C
Rationale: An intramuscular (IM) injection delivers fluid directly into a muscle, commonly used for vaccines or medications due to muscles' rich blood supply, ensuring rapid absorption. Sites like the deltoid or gluteus maximus are typical targets. Dileguilist appears to be a typo or nonsensical term. Prime mover is a muscle role, not an injection type. Fixators stabilize muscles, not receive injections. Intramuscular injection is a precise medical term matching the description, making it the correct choice. Its clinical relevance lies in its efficiency and common application, distinguishing it from subcutaneous or intravenous methods, and it reflects a practical aspect of muscle anatomy in healthcare.