What effect does increasing patient size have on receptor exposure?

Increasing patient size predominantly decreases receptor exposure due to a number of factors related to the physics of radiation transmission and attenuation. As the size of a patient increases, more tissue must be traversed by the X-ray beam before reaching the imaging receptor. This additional tissue presents more opportunities for the X-rays to be absorbed or scattered.

The thicker or denser the area the X-ray must penetrate, the fewer X-rays effectively reach the receptor, resulting in lower exposure. This is critical in radiologic imaging, as it influences the quality of the image obtained. Without compensatory adjustments, such as increasing the exposure time or the amount of radiation used, larger patients often yield images that are underexposed.

In contrast, factors such as spatial resolution and distortion are not directly affected by patient size in the same manner. Spatial resolution is more significantly influenced by the imaging system, while distortion typically relates to the object's alignment to the receptor, rather than the size of the patient themselves. Hence, the most accurate understanding of the effect of patient size on receptor exposure is a decrease, aligning with the selected answer.