Alar

Alar is an adjective derived from the Latin alaris, meaning winglike. In anatomy and medicine, it describes structures that resemble wings or are associated with winglike projections.

In neuroanatomy, the alar plate refers to the dorsal portion of the embryonic neural tube, which gives rise to sensory neurons and pathways. It is situated above the basal plate, with the sulcus limitans marking the boundary between the alar (sensory) and basal (motor) regions. The term is also used in descriptions of brainstem and spinal cord organization to distinguish sensory from motor areas.

In facial anatomy, the term appears in reference to the alar cartilages of the nose (lower lateral nasal cartilages). These alar cartilages form the “wings” of the nose and define the shape and contour of the nostril rims, collectively known as the alae nasi.

In the craniovertebral region, the alar ligaments connect the dens (odontoid process) to the occipital bones. These paired ligaments help stabilize the atlanto-occipital joint and limit excessive rotation of the head.

The alar fascia is another neck structure named for its winglike appearance. It is a layer of the deep cervical fascia that helps partition the retropharyngeal space, contributing to the anatomy relevant to the spread of infections in the neck.

Overall, alar terminology appears in multiple anatomical contexts to denote winglike projections or connections.