The bell of the stethoscope is used to hear which type of sounds during physical assessment?

RAK Nursing Officer - 2019

Fundamental of Nursing

Easy

Appeared in: RAK Nursing Officer - 2019

Explanation

The bell of the stethoscope is the smaller, concave part of the chest piece designed specifically to hear low-frequency or low-pitched sounds.
It is most effective for auscultating abnormal heart sounds like S3 (ventricular gallop) and S4 (atrial gallop), the diastolic murmur of mitral stenosis, and some vascular bruits.
Proper technique requires applying the bell with very light pressure against the skin, just enough to create a seal. Pressing firmly will stretch the skin, making it function like a diaphragm and filtering out the very sounds the bell is designed to detect.

Option B: This option is too general. Heart sounds consist of both high-frequency components (like S1 and S2) and low-frequency components (like S3 and S4). The bell is only used for the low-frequency sounds.
Option C: Lung sounds are generally high-pitched sounds. The diaphragm, which is designed for high frequencies, is the appropriate part of the stethoscope for assessing lung sounds.
Option D: This is the opposite of the bell's function. The diaphragm is the part of the stethoscope used to hear high-frequency sounds.

Clinical Relevance

Nursing practice connection: Use the key finding related to Auscultation Technique using a Stethoscope to guide bedside assessment, documentation, and the next nursing action.
Correctly using the bell versus the diaphragm is a fundamental nursing skill for an accurate cardiovascular and vascular assessment, preventing misinterpretation of sounds.
Failing to use the bell with light pressure can lead to missing critical diagnostic sounds like an S3 gallop, which can be an early sign of heart failure, or vascular bruits, which can indicate arterial narrowing.
What if? - If a patient has a known history of heart failure, the nurse should make a point to use the bell over the apex of the heart (mitral area) to specifically listen for an S3 sound, as its presence or absence is a key indicator of the patient's current fluid status and cardiac function.

How to Approach the Question

First, identify the core of the question, which asks about the specific function of the 'bell' of a stethoscope.
Recall the two main parts of a stethoscope head: the bell and the diaphragm, and their distinct purposes.
Remember the fundamental rule: the bell is for low-pitched sounds, and the diaphragm is for high-pitched sounds.
Evaluate the options based on this knowledge. 'Low frequency sounds' directly and accurately describes the function of the bell.
Analyze why the other options are incorrect. 'Heart sounds' is too broad, 'Lung sounds' are typically high-frequency, and 'High frequency sounds' is the function of the diaphragm.

Concept Tested & Keywords

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E6 Nursing Fundamentals Potter Perry 12e Part 3 pp. 65-67, 98-100