The septum is a thin partition or membrane that divides two cavities or soft massesor tissue in an organism. In the anatomy of the human face, the nasal septum is that membrane between each nostril. The external portion also known as the nasal columella. The alar groove is typically a C-shaped depression formed where the ala is joined to the cheek. The septum is one of the sites of traditional and contemporary body-piercing.Also see ala and alar groove, bust, philtrum, portrait, and self-portrait.