Which structure is primarily affected by an indirect inguinal hernia?

An indirect inguinal hernia involves the protrusion of abdominal contents through a defect in the abdominal wall, typically occurring at the inguinal canal. This type of hernia primarily affects the peritoneum. In an indirect inguinal hernia, the herniated tissue descends along the spermatic cord in males and can pass into the scrotum, which indicates that the peritoneal lining is involved in this defect.

The peritoneum is the serous membrane that forms the lining of the abdominal cavity and is responsible for enclosing the abdominal organs. In this context, the hernia represents a weakness in the peritoneal wall, allowing for the passage of visceral contents from the abdominal cavity into the inguinal canal.

The other structures listed, such as the ureter, testes, and inferior epigastric vessels, are either adjacent to or influenced by the hernia but are not the primary structures affected in the case of an indirect inguinal hernia. The focus here is on the peritoneum, which is the structure that is primarily compromised during the herniation process.