Which vein drains the esophagus?

The vein that drains the esophagus is the inferior thyroid vein. This vein is part of the venous system that collects blood from the lower part of the thyroid gland and structures in the neck, including the esophagus. The inferior thyroid vein plays a significant role in draining blood from the cervical portion of the esophagus, which helps facilitate proper venous return from this area to the heart.

When considering why this choice is appropriate, it's helpful to understand the anatomy of the esophagus and its vascular supply. The veins draining the esophagus typically connect to the brachiocephalic veins and the superior vena cava, with the inferior thyroid vein contributing to this drainage pathway from the lower cervical esophagus.

The other veins listed serve different regions and structures. The internal jugular vein primarily drains blood from the head and neck, the subclavian vein is involved in draining the upper extremities and some thoracic structures, and the external jugular vein drains blood from the superficial structures of the head and neck. None of these veins are directly responsible for draining the esophagus itself. Thus, the inferior thyroid vein is the most appropriate choice for this function.