39. Nasal cavities

The anatomical structures that play a central role in the res piratory system are located in the head and neck as well as the thorax.

Nasal cavities are separated by the nasal septum, which consists of the vomer, the perpendicular plate of the ethmoid bone, and the septal cartilage. The lateral wall of each nasal cavity features three scroll—shaped bony structures called the nasal conchae. The nasal cavities communicate posteriorly with the nasopharynx through the choanae. The spaces inferior to each concha are called meatus. The paranasal sinu—ses and the nasolacrimal duct open to the meati. The inferior concha is a separate bone, and the superior and middle conchae are parts of the ethmoid bone.

Inferior meatus. The only structure that opens to the inferior meatus is the nasolacrimal duct. This duct drains lacrimal fluid (i. e., tears) from theTneaTaraspect of the orbit to the nasal cavity.

Middle meatus: the hiatus semilumaris contains openings of frontal and maxillary sinuses and americy ethmo—idal air cells. The bulla ethmoidalis contains the opening for'the middle ethmoidal air cells.

Superior meatus contains an opening for thff'posterior ethmoidal air cells.

Sphenoethmoidal recess is located above the superior concha and contains an opening for the sphenoid sinus.

Innervation: Somatic innervation. General sensory information from the lateral wall and septum of the nasal cavity is conveyed to the CNS by branches of V, and V2.

Autonomic innervation. Preganglionic parasympathetic fibers destined to supply the glands of the nasal mucosa and the lacrimal gland travel in the nervus intermedius and the greater superficial petrosal branches of the facial nerve (CN VII). These fibers synapse in the pte—rygopalatine ganglion, which is located in the pterygopa—latine fossa. Postganglionic fibers traveling to the mucous glands of the nasal cavity, paranasal air sinuses, hard and soft palate, and the lacrimal gland follow branches of V2 and in some cases V1, to reach their destinations.

New words

anatomical – анатомический

respiratory system – дыхательная система

head – голова

neck – шея

nasal cavities – носовые впадины

the perpendicular plate – перпендикулярная пластина

ethmoid – решетчатый

septal – относящийся к перегородке

nasal conchae – носовой раковина

paranasal – параносовой

sinuses – пазухи

nasolacrimal – назолакримальный

duct – трубочка

drain – проток

tears – слезы

orbit – орбита

maxillary – верхнечелюстной

bulla – булла