dots-menu
×

Home  »  Anatomy of the Human Body  »  pages 994

Henry Gray (1825–1861). Anatomy of the Human Body. 1918.

pages 994


The Nasal Cavity (Cavum Nasi; Nasal Fossa)—The nasal chambers are situated one on either side of the median plane. They open in front through the nares, and communicate behind through the choanæ with the nasal part of the pharynx. The nares are somewhat pear-shaped apertures, each measuring about 2.5 cm. antero-posteriorly and 1.25 cm. transversely at its widest part. The choanæ are two oval openings each measuring 2.5 cm. in the vertical, and 1.25 cm. in the transverse direction in a well-developed adult skull.
  For the description of the bony boundaries of the nasal cavities, see pages 194 and 195.
  Inside the aperture of the nostril is a slight dilatation, the vestibule, bounded laterally by the ala and lateral crus of the greater alar cartilage, and medially by the medial crus of the same cartilage. It is lined by skin containing hairs and sebaceous glands, and extends as a small recess toward the apex of the nose. Each nasal cavity, above and behind the vestibule, is divided into two parts: an olfactory region, consisting of the superior nasal concha and the opposed part of the septum, and a respiratory region, which comprises the rest of the cavity.


FIG. 855– Lateral wall of nasal cavity. (See enlarged image)

Lateral Wall (Figs. 855, 856).—On the lateral wall are the superior, middle, and inferior nasal conchæ, and below and lateral to each concha is the corresponding nasal passage or meatus. Above the superior concha is a narrow recess, the sphenoethmoidal recess, into which the sphenoidal sinus opens. The superior meatus is a short oblique passage extending about half-way along the upper border of the middle concha; the posterior ethmoidal cells open into the front part of this meatus. The middle meatus is below and lateral to the middle concha, and is continued anteriorly into a shallow depression, situated above the vestibule and named the atrium of the middle meatus. On raising or removing the middle concha