26.2 : 鼻子和鼻腔

The nose is the primary passageway for air entering the respiratory system.

Its visible part, the external nose, is supported by the frontal bone, nasal bones, and maxillae and is supplemented by a cartilaginous framework.

The external nose features two nostrils that lead to the nasal vestibules.

Inhaled air first passes through the nasal vestibule, where larger dust particles are filtered by skin containing coarse hairs.

The nasal cavity, located below the nasal bone and above the oral cavity, is divided into right and left parts by the nasal septum.

Each nasal cavity has superior, middle, and inferior conchae, forming three grooves called the superior, middle, and inferior meatuses.

Together, they increase the internal nose's surface area, helping to moisten the air and trap smaller dust particles.

The nasal cavity is encircled by paranasal sinuses in the frontal, sphenoid, ethmoid, and maxillary bones. These mucous membrane-lined spaces release mucus into the nasal cavities.

To the posterior side, the nasal cavity connects to the pharynx through paired internal nares.