Lymph drainage of the conjunctiva: topographic anatomic study in calves.

The topographic pattern of lymph drainage from the conjuctiva was ascertained in 1- to 2-week-old calves. Multiple, small lymph vessels within and on the surface of the orbicularis oculi muscle converged to form fewer vessels which followed the course of the superficial temporal artery and vein or crossed the zygomatic arch in a more rostral position to reach the primary site of lymph collection, the parotid lymph node. Marker dye, injected into the subconjunctiva, was collected in the midrostral and rostroventral parts of the node. Drainage from the parotid node passed via multiple lymph vessels into the lateral retropharyngeal node, where marker dye concentrated in the rostrodorsal aspect of the node. Single or multiple lymph vessels carried drainage from the lateral retropharyngeal node indirectly by way of the cranial deep cervical lymph node or directly into the tracheal lymph trunk.