The lacrimal system drains into the nasal cavity below the anterior inferior aspect of the inferior turbinates. As in the rest of the upper respiratory tract, nasal membranes are composed of ciliated pseudostratified glandular columnar epithelium. Cilia beat in unison to propel mucus from the nasal cavity and paranasal sinuses toward the nasopharynx where it can be swallowed. Mucociliary transport relies on mucus production and ciliary function. Normally, the nose and paranasal sinuses produce approximately 1 quart of mucus in a 24-hour period.
Mucus contains immunoglobulins A and E and muramidase.
Blood and autonomic nerve supply control secretions and level of congestion of nasal membranes. General innervation to the nose is from the autonomic nervous system, with the parasympathetic nerves supplying the resting tone and controlling secretions. Contributions of nerve supply are from the facial nerve originating at the inferior salivatory nucleus and following along the distribution of the facial nerve through the sphenopalatine ganglion. Blood supply to the nose comes from branches of the internal and external carotid artery systems. Terminal branches of the internal maxillary artery supply the majority of mucosal surfaces of the nasal cavity.