Which of the following visceral structures does NOT typically refer pain into the shoulders?

The kidneys do not typically refer pain into the shoulders, making this the correct choice. Visceral pain can often be referred to areas of the body that are not directly connected to the source of the discomfort. The heart, gallbladder, and spleen are known to refer pain to the shoulder area due to their anatomical and neurological connections.

For instance, pain from the heart commonly radiates to the left shoulder and arm, which is a phenomenon often seen in cases of angina or myocardial infarction. The gallbladder can refer pain to the right shoulder area, especially in situations where gallbladder disease or gallstones are present. Similarly, the spleen can also refer pain to the left shoulder, particularly related to incidents like splenic enlargement or rupture.

In contrast, while the kidneys can produce pain that radiates to the back or side due to issues like kidney stones or infections, they do not have a common referral pattern that extends to the shoulder region. This distinction is essential in clinical practice as it aids in accurately diagnosing the source of pain based on its referral pattern.