AAMC FL Practice Exam

Which feature of an ultrasound transducer acts as the source?

1. The observed fetus

2. The emitted sound wave

3. The transducer itself

4. The surrounding air medium

The correct answer is: The transducer itself

The transducer itself acts as the source in an ultrasound system because it is responsible for generating the sound waves used in the imaging process. The transducer contains piezoelectric crystals that convert electrical energy into acoustic energy, producing the sound waves that penetrate the body to create images of internal structures. When these sound waves encounter different tissues in the body, they are reflected back to the transducer. The reflected waves are then converted back into electrical signals, which are processed to form an image. This function of sound wave emission is central to the operation of ultrasound technology, distinguishing the transducer as the active component that initiates the imaging process. In contrast, the observed fetus and the emitted sound wave are results of the ultrasound process, not the source. The surrounding air medium plays no direct role in generating the ultrasound waves; it merely serves as the environment through which the waves travel. Thus, the transducer is the critical component that produces the sound waves necessary for ultrasound imaging.