Yellow bone marrow contains a large percentage of:
Sharpey’s fibers
Elastic tissue
Spongy bone
Fat
Blood-forming cells
The Correct Answer is D
Choice A reason: Sharpey’s fibers are collagen fibers that anchor the periosteum to the underlying bone. They are structural, not part of bone marrow.
Choice B reason: Elastic tissue is found in ligaments and certain connective tissues but is not a major component of yellow bone marrow.
Choice C reason: Spongy bone surrounds the marrow cavities but is not the content of yellow marrow itself.
Choice D reason: Fat is the correct answer. Yellow bone marrow primarily consists of adipocytes and serves as an energy reserve. It replaces red marrow in many bones as a person ages.
Choice E reason: Blood-forming cells are found in red bone marrow, not yellow marrow. Red marrow is responsible for hematopoiesis.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Choice A reason: Muscle relaxation is primarily governed by the removal of calcium ions from the sarcoplasm and the cessation of neural stimulation. Wave summation, on the other hand, is a mechanism that enhances contraction, not relaxation.
Choice B reason: While wave summation can contribute to sustained contractions, it does not directly prevent fatigue. In fact, repeated summation without rest can lead to fatigue due to depletion of energy stores and accumulation of metabolic byproducts.
Choice C reason: Wave summation increases the force of muscle contraction by layering successive stimuli before the muscle has fully relaxed. This results in a stronger, more sustained contraction due to residual calcium and continued cross-bridge cycling. It is a key physiological mechanism for producing smooth and powerful movements.
Choice D reason: Calcium ion release is essential for initiating muscle contraction. Wave summation does not reduce calcium release; rather, it builds on residual calcium from previous stimuli to enhance contraction force.
Correct Answer is A
Explanation
Choice A reason: The sarcomere is the smallest contractile unit of a skeletal muscle. It is composed of actin and myosin filaments arranged in a precise pattern that allows for muscle contraction. Sarcomeres are repeated along the length of a myofibril and are responsible for the striated appearance of skeletal muscle.
Choice B reason: The sarcoplasmic reticulum is a specialized form of endoplasmic reticulum in muscle cells that stores and releases calcium ions, which are essential for muscle contraction. However, it is not the contractile unit itself.
Choice C reason: The sarcolemma is the plasma membrane of a muscle fiber. It plays a role in conducting electrical signals but is not the structural unit responsible for contraction.
Choice D reason: A myofibril is a long, cylindrical organelle found within muscle cells that contains many sarcomeres. While it contributes to muscle contraction, it is composed of multiple sarcomeres and is not the fundamental unit.
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.