A young woman presents with abdominal pain and cervical motion tenderness. What structure is likely affected?

In the scenario presented, the combination of abdominal pain and cervical motion tenderness suggests the presence of a gynecological issue, likely related to the reproductive system. Cervical motion tenderness is particularly indicative of conditions such as pelvic inflammatory disease (PID), which often involves infection or inflammation of the uterine (fallopian) tubes.

The uterine (fallopian) tubes are responsible for transporting eggs from the ovaries to the uterus and are closely associated with the processes of fertilization and early pregnancy. When there is an infection or inflammation in this area, it can lead to significant discomfort and pain radiating throughout the lower abdomen. This condition often presents alongside other symptoms, such as fever and abnormal vaginal discharge.

While other structures like the appendix, bladder, and endometrium could be related to abdominal pain, they would not typically present with cervical motion tenderness, which points more directly to a gynecological origin of the symptoms. Thus, the uterine (fallopian) tube is the most likely structure affected in this clinical scenario.