Normal chewing in humans involves _____ of the mandible.
Protraction and retraction
Opposition and reposition
Elevation and pronation
Elevation and depression
Supination and depression
The Correct Answer is D
Choice A reason: Protraction and retraction refer to the forward and backward movement of the mandible, which occurs during certain chewing motions but is not the primary movement involved in chewing.
Choice B reason: Opposition and reposition are movements of the thumb and fingers, not the mandible. They are unrelated to chewing.
Choice C reason: Pronation is a rotational movement of the forearm, not the mandible. Elevation is correct, but pronation does not apply to jaw movement.
Choice D reason: Elevation and depression are the correct movements involved in chewing. Elevation closes the jaw (biting), and depression opens it (jaw lowering).
Choice E reason: Supination is also a forearm movement and does not apply to the mandible. Depression is correct, but supination is irrelevant here.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
Choice A reason: Cross bridges are formed between actin and myosin during contraction. T tubules do not hold them in place; their role is electrical, not structural.
Choice B reason: While T tubules are embedded in the muscle fiber, their function is not to provide structural support. That role is fulfilled by connective tissues like endomysium and cytoskeletal proteins.
Choice C reason: G and F actin are stabilized by proteins like tropomyosin and nebulin, not T tubules. T tubules are involved in electrical signaling.
Choice D reason: This is the correct answer. T tubules are invaginations of the sarcolemma that conduct action potentials deep into the muscle fiber. This ensures that the signal for contraction reaches all parts of the muscle simultaneously, triggering calcium release from the sarcoplasmic reticulum.
Choice E reason: Glucose synthesis occurs in the liver and other tissues via gluconeogenesis. Muscle cells use glucose for energy but do not synthesize it through T tubules.
Correct Answer is B
Explanation
Choice A reason: Myofilaments are microscopic protein filaments composed of actin and myosin. They are the smallest contractile units within myofibrils and do not represent a bundle of muscle fibers.
Choice B reason: Fascicle is the correct term for a bundle of muscle fibers. Each fascicle is surrounded by perimysium and contains multiple muscle cells (myocytes), allowing coordinated contraction and force generation.
Choice C reason: Myofibrils are intracellular structures found within individual muscle cells. They contain repeating units of sarcomeres and are not bundles of muscle fibers.
Choice D reason: Whole muscle refers to the entire organ composed of multiple fascicles, connective tissues, blood vessels, and nerves. It is a larger structure than a bundle of muscle fibers.
Choice E reason: A muscle cell, or myocyte, is a single unit within a fascicle. It is not a bundle but an individual contractile cell.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.