The smooth, thin membrane that lines the chambers of the heart and forms the surface of the heart valves is the:
Pericardium.
Endocardium.
Myocardium.
Epicardium.
The Correct Answer is B
The endocardium is the thin inner lining of the heart chambers and also forms the surface of the heart valves.
Some possible explanations for the other choices are:
Choice A is wrong because the pericardium is the sac that surrounds the heart and consists of two layers: the fibrous pericardium and the serous pericardium.
Choice C is wrong because the myocardium is the thick middle layer of muscle that allows the heart chambers to contract and relax to pump blood to the body.
Choice D is wrong because epicardium is another name for the visceral layer of the serous pericardium that is fused to the heart and is part of the heart wall.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
This helps prevent blood pooling and clotting in the lower extremities, which can lead to deep vein thrombosis and pulmonary embolism.
It also reduces the workload on the heart and improves blood circulation throughout the body.
Choice A is wrong because contraction of muscles does not stimulate the arteries to vasodilate, but rather causes vasoconstriction in the inactive tissues to divert blood flow to the active muscles.
Choice B is wrong because the contraction of muscles itself does not increase heart rate significantly unless it is part of an aerobic exercise that elevates the metabolic demand.
Burning calories and keeping the heart strong are benefits of regular physical activity, not occasional muscle contraction.
Choice C is wrong because contraction of the leg muscles does not stimulate baroreceptors, which are pressure-sensitive receptors located in the walls of the arteries.
Baroreceptors respond to changes in blood pressure and signal the autonomic nervous system to adjust heart rate and vascular resistance accordingly.
Contraction of the leg muscles does not affect blood pressure or heart rate directly but rather assists with venous return.
Correct Answer is C
Explanation
Positive feedback mechanisms move conditions away from the normal state.
They amplify the original action and produce more of the same effect.
For example, blood clotting and childbirth are positive feedback mechanisms.
Choice A is wrong because positive feedback mechanisms usually produce unstable conditions.
They do not resist change but rather enhance it.
Choice B is wrong because positive feedback mechanisms do not cause long-term changes.
They are ultimately stopped by negative feedback loops once the process they were used for is complete.
Choice D is wrong because positive feedback mechanisms do not bring conditions back to the normal state.
That is the role of negative feedback mechanisms, which oppose the stimulus and restore homeostasis.
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