trifurcation

Trifurcation is the process or result of dividing into three branches. The term comes from Latin tri- meaning three and furca meaning fork. In biology and medicine, trifurcation refers to a three-way branching of a structure such as a vessel, nerve, or airway. While many branches bifurcate into two, trifurcations occur in various anatomical contexts and can have clinical or functional significance, especially where branching patterns influence flow, innervation, or patency.

A well-known example is the trigeminal nerve, which divides within the skull into three major divisions: ophthalmic (V1), maxillary (V2), and mandibular (V3). In vascular anatomy, trifurcations can occur as variants where a single artery splits into three named branches, though this is less common than bifurcation. The concept also appears in airway trees and nervous systems, where three-way splits can shape how air, blood, or nerve signals are distributed through tissues.

Beyond biology, trifurcation appears in other disciplines. In botany, stems or roots may show three-way branching. In hydrology, a river can trifurcate into three channels. In mathematics and computer science, a node or junction may be described as trifurcating when three pathways emerge from a single point.

Understanding trifurcations aids anatomical labeling, surgical planning, radiologic interpretation, and the study of branching patterns across systems. See also bifurcation and quadrifurcation.