ATI RN
Questions for Muscular System Questions
Question 1 of 5
The nurse explains that the major advantage of the external fixation device is that the patient:
Correct Answer: C
Rationale: External fixation stabilizes fractures with pins and a frame outside the skin, allowing precise alignment. Its major advantage is greater freedom of movement, as the limb isn't encased like in a cast, permitting easier access for wound care and some mobility, depending on the injury. Healing speed depends on the fracture, not the device alone. Weight-bearing varies by case and isn't immediate. Pain levels aren't inherently lower than other methods. Movement freedom stands out, enhancing patient comfort and care flexibility, distinguishing external fixation from more restrictive options like casts or traction.
Question 2 of 5
The pelvic floor; the space between the anus and the scrotum in the male and between the anus and the vulva in the female.
Correct Answer: C
Rationale: The perineum is the region of the pelvic floor between the anus and scrotum in males or vulva in females, encompassing both the anal and urogenital triangles. It serves as the external base of the pelvic cavity and contains muscles, nerves, and other structures. Compartment refers to muscle groups, not this region. The urogenital triangle is only part of the perineum, not the whole area. Fixators are stabilizing muscles, unrelated to this anatomical space. The perineum's definition matches the question perfectly, making it the correct answer, as it broadly describes the pelvic floor area between these landmarks, critical for understanding pelvic anatomy and clinical conditions like perineal tears.
Question 3 of 5
This type of muscle works by stabilizing the origin of the agonist so that it can act more efficiently.
Correct Answer: D
Rationale: Fixators stabilize the origin of the agonist (prime mover), ensuring its force is directed efficiently toward the intended movement. For example, during arm abduction, scapular fixators (e.g., trapezius) hold the scapula steady so the deltoid can lift the arm. Synergists assist the agonist by refining motion, not stabilizing origins. The agonist is the main mover, not a stabilizer. Antagonists oppose the agonist. Fixators' role in anchoring the origin enhances movement precision, making it the correct answer, as it supports the agonist's action by preventing unwanted shifts at the stationary attachment, a key aspect of coordinated muscle function.
Question 4 of 5
Tim ate something that is not agreeing with his digestive tract. He needs to go to the bathroom to defecate, but there is a line. What muscle helps keep the anal canal and anus closed?
Correct Answer: D
Rationale: The external anal sphincter, a voluntary skeletal muscle, keeps the anal canal and anus closed to prevent defecation until appropriate, allowing Tim to wait. Bulbospongiosus aids in urination and erection, not anal control. Ischiocavernosus supports erection, not defecation. Obturator internus rotates the thigh, unrelated here. The external anal sphincter is the correct answer, as it provides conscious control over defecation, distinct from the involuntary internal sphincter, and is key in maintaining continence under digestive distress.
Question 5 of 5
A woman complains of problems going up steps. Tests reveal hip extension weakness but no issues with hip flexion or knee flexion or extension. What muscle is most likely damaged?
Correct Answer: B
Rationale: Hip extension, critical for climbing steps, is primarily powered by the gluteus maximus, which extends the thigh backward. Weakness here impairs stair ascent, while intact hip flexion (iliopsoas) and knee flexion/extension (hamstrings/quadriceps) suggest a specific issue. Adductor magnus adducts, not extends. Gluteus medius abducts and stabilizes. Semitendinosus flexes the knee, not hip extension. Gluteus maximus is the correct answer, as its damage aligns with isolated hip extension weakness, a key mover in upward locomotion.