Final answer:
The concave profile of the nose is referred to as the philtrum, a surface that connects the nose's apex to the upper lip.
Step-by-step explanation:
The concave profile of the nose mentioned in your question refers to the philtrum, which is the concave surface connecting the apex of the nose to the upper lip. This feature is part of the external structure of the nose, which impacts its appearance and function. The nose itself has a complex internal structure including the nasal cavity, which is separated into left and right sections by the nasal septum and houses the superior, middle, and inferior nasal conchae. These conchae, especially the inferior nasal concha, are curved bony plates that project into the nasal cavity and are responsible for warming, moisturizing, and trapping particles in the air we breathe.