A nurse is performing a lung assessment on a client. The nurse should understand which information about lung structures?

A) A heart murmur is a high-pitched sound caused by a narrowing of a heart valve:
While it's true that a narrowing of a heart valve (stenosis) can cause a murmur, the description of a heart murmur as a "high-pitched sound" due to this narrowing is overly specific and does not fully explain what a murmur is. A murmur is not always high-pitched, and it is caused by turbulent blood flow, which may occur for various reasons beyond just valve stenosis.

B) A heart murmur is an extra sound heard from blood entering a rigid heart chamber:
This description is somewhat inaccurate. While murmurs can result from turbulent blood flow through the heart chambers or valves, the idea that murmurs are "extra sounds from blood entering a rigid heart chamber" is misleading. A murmur occurs when there is turbulent blood flow, which can happen in both rigid and non-rigid chambers. The key point is that it's the turbulent flow, not just rigidity, that causes the sound.

C) A heart murmur is a sound generated by inflammation around the heart muscle:
This is incorrect. Inflammation around the heart muscle, such as in pericarditis, can cause chest pain or other symptoms but does not generate a heart murmur. A murmur is caused by turbulent blood flow, which can result from various heart valve issues (e.g., stenosis, regurgitation) or defects in the heart's structure (e.g., septal defects), not from inflammation around the heart muscle.

D) A heart murmur indicates turbulent blood flow through a valve in the heart:
This is the most accurate description. A heart murmur is typically caused by turbulent or irregular blood flow through a heart valve. This can occur for several reasons, such as valve stenosis (narrowing), valve regurgitation (leakage), or congenital heart defects that cause abnormal flow patterns. The turbulent flow disrupts the normal laminar (smooth) blood flow, creating the characteristic sound that can be heard with a stethoscope. Murmurs can vary in timing, pitch, and intensity depending on the nature of the flow disturbance.

A) Fifth intercostal space, midaxillary line:
This is incorrect. The fifth intercostal space at the midaxillary line is a location that can be assessed for tactile fremitus, but it is not typically where fremitus is felt most intensely. Fremitus tends to be stronger near the midline structures, such as over the trachea, rather than at this lateral position, which is more peripheral.

B) Between the scapulae:
This is the correct answer. Tactile fremitus is usually most intense over the area between the scapulae and near the sternum. This is because the bronchi and trachea are located close to the chest wall in these regions, creating more intense vibrations that can be palpated during assessment. The fremitus is transmitted through the airways and is easiest to feel when the lung tissue is close to the chest wall, as in the area between the scapulae.

C) Third intercostal space, midaxillary line:
This is incorrect. The third intercostal space at the midaxillary line is not typically the site where tactile fremitus is most prominent. This area is more peripheral, and fremitus tends to be weaker here compared to regions closer to the sternum or between the scapulae where the lungs are nearer to the chest wall.

D) Over the lobes, posterior side:
This is incorrect. While tactile fremitus can be assessed over the posterior lobes of the lungs, it is not generally felt most intensely here. Fremitus is usually stronger near the midline of the chest (sternum) or between the scapulae, and tends to be weaker as you move laterally or toward the lower lobes of the lungs.