Medullaris

Medullaris is a Latin term meaning 'of the medulla' and is used in anatomical nomenclature as an attributive suffix. It appears most commonly in terms such as conus medullaris, the tapered end of the spinal cord, and in phrases describing structures related to the spinal cord or to bone marrow (medulla).

Conus medullaris refers to the conical termination of the spinal cord. In adults it is typically located at the L1–L2 vertebral level, though its position can vary with age and spinal morphology. The cord proper ends at the conus, and the nerve roots below form the cauda equina. The filum terminale arises at the tip of the conus and descends within the dural sac to attach to the coccyx.

Developmentally, the conus medullaris forms during embryogenesis through secondary neurulation. Its level relative to the vertebral column changes with growth, and imaging or examination may note minor variation between individuals.

Clinically, conus medullaris pathology can cause conus medullaris syndrome, characterized by early bladder and bowel dysfunction, symmetrical leg weakness, and varying sensory loss, often with relatively preserved knee reflexes. This presentation differs from cauda equina syndrome, which tends to be asymmetric and radicular.

Besides the spinal term, medullaris is used in other contexts to denote structures related to the medulla, such as bone marrow (medulla ossis). Etymologically, it reflects its Latin root and indicates a relationship to the medulla in various anatomical terms.