Nose & Nasal Cavity
The nose is the first component of the respiratory system, as it allows the air to enter the airways. The nose thus facilitates intake of oxygen and discharge of carbon dioxide and also contains the receptors for the sense of smell.
The external nose is pyramidal in shape, with its root being continuous with the forehead. The root is continued by the dorsum, which terminates at the tip of the nose called apex. On each side of the midline is a nostril (nare), which represents the entrance to the nasal cavity.
The nasal cavity is the internal part of the nose. It is divided into two halves by the nasal septum. Anterior openings of the cavity are the nostrils. Posteriorly, the cavity communicates with the pharynx via openings called choanae. The nasal cavity is lined with mucous membranes that help to moisten, warm, and filter air being taken in.
Learn the anatomy of the nose and nasal cavity using interactive animations and labeled diagrams below. Get the full respiratory system revision guide.
Nose and Nasal Cavity | Structure & Functions
An introduction to the nose and the nasal cavity. The nose is the first portion of the respiratory tract and serves as a vent for air exchange. Inhaled air is warmed, moistened, and cleaned so it can travel safely into other parts of the respiratory tract.
Supportive Bones and Cartilages of the Nasal Cavity
The nasal cavity is posterior to the nose and is framed and supported by several bones and cartilages. The nasal septum divides the nasal cavity into two chambers.
Supportive Cartilages and Bones of the Nose
The nose is supported by upper and lower cartilages along with the maxilla and nasal bones. A pair of nasal bones support the bridge of the nose and the medial plates and frontal processes of the maxilla bones support the sides of the nose.
Turbinate Bones (Nasal Conchae)
There are three turbinates on each side of the nasal cavity (Superior, middle, and inferior). Grooves are found between the curved turbinates. During inhalation, air is directed over and under the turbinates. The surface mucosa conditions or prepares the air so it can safely travel into the lungs.
Vestibule Region of the Nasal Cavity
The vestibule is the portion of the nasal cavity that lies directly posterior to the external nares. It is lined by stratified squamous epithelium providing as a barrier that helps protect the vestibule from damage. A layer of mucus typically covers the outer surface of the vibrissae.
Nasal mucosa (respiratory mucosa): gross and microscopic anatomy
Inside the nasal cavity, the surfaces of the turbinate bones (= nasal conchae) and meatuses are lined by respiratory mucosa (= nasal mucosa).
Olfactory epithelium: structure and function
The olfactory mucosa detects odor-producing chemicals. The epithelium layer includes specialized nerve cells and non-motile cilia to provide a binding site for odorants. Mucus covers the receptor cilia where odorants dissolve and bind to cilia receptors. The binding produces an electrochemical impulse.