Nasal cavity and paranasal sinuses

Nasal cartilage

major alar cartilage

nasal septal cartilage

Nasal bones

ethmoid

vomer

maxilla

palatine

sphenoid

Nasal Cavity

Superior 1/3 is the olfactory area

inferior 2/3 is the respiratory area

Nasal concha

aka turbinates; create turbulent airflow during inspiration

1. modifies air: warms, humidifies and filters particles

2. senses smell: olfactory area, organ of smell; sniffing draws air to the area

Conchae fill majority of nasal cavity

foreign objects or inflammation of mucosa can inhibit airflow

paranasal sinuses

sir filled, lined by resp epithelium. FXNs: warm and humidify air, reduce weight of the skull, contributing to voice resonance

Maxillary sinus must

drain against gravity

Superior meatus

openings of posterior ethmoidal air cells

Middle meatus

ethmoidal bulla

Semilunar hiatus: frontonasal duct, openings of anterior ethmoidal air cells, opening of maxillary sinus, openings of middle ethmoidal air cells

Inferior meatus

opening of nasolacrimal duct

sphenoethmoidal recess

opening of sphenoid sinus

Sphenoid sinus drains into

sphenoethmoidal recess

posterior air cells

drains into the superior meatus

nasolacrimal duct drains

into the inferior meatus

Frontal, middle ethmoidal air cells, anterior ethmoidal air cells, and maxillary sinus

drains into the middle meatus

Nasolacrimal apparatus

tears produced in lacrimal gland--through punctum into lacrimal canaliculi--collect in lacrimal sac--travel down nasolacrimal duct to inferior nasal meatus

lacrimal fluid stimulation

via CN VII

Arteries of the nasal cavity

ophthalmic artery, maxillary artery, facial artery

Nasal cavity has rich blood supply

anastomosing arteries meet at kiesselbach's plexus

epistaxis (nose bleeds)

From Ophthalmic a

anterior and posterior ethmoidal a

supply the superior nasal cavity

From maxillary a

sphenopalatine and greater palatine a

perfuses majority of nasal cavity, perfuses floor and septum

sphenopalatine enters through sphenopalatine foramen

Descending palatine a enters

oral cavity via the greater palatine foramen as the greater palatine a. Then enters nasal cavity via incisive foramen

From facial a

superior labial a which supplies the inferior nasal cavity

Venous drainage of the nasal cavity

pterygoid venous plexus--facial vein--ophthalmic veins to the cavernous sinus--nasal emissary v to superior sagittal sinus

Sinus infection leads

to cavernous sinus thrombosis

Lymphatic drainage of nasal cavity

anterior regions drains into submandibular nodes--deep cervical nodes (palpable)

posterior regions drain into the deep cervical nodes or via the retropharyngeal nodes (not palpable)

SVA of nasal cavity

Olfactory n CN I

GSA of nasal cavity

Branches of trigeminal n: ophthalmic (v1) and maxillary (v2)

anterior ethmoidal innervates nasal cavity

posterior ethmoidal innervates air cells and sphenoid sinus.

GVE-P CN VII of nasal cavity; stimulate mucosal glands

1. superior salivatory nucleus in brainstem

2. Preganglionic fibers: greater petrosal nerve

3. joins with postganglionic neurons towards the pterygoid canal

4. postganglionic cell bodies in pterygopalatine ganglion

5. distribute w/ V2 branches throughout the nasal cavity

GVE (sympathetics) regulate blood flow to venous plexus

1. Pre starts at T1-T3 and synapse at postgang in superior cervical ganglion

2. postgang fibers distribute via a plexus around the internal carotid and becomes deep petrosal n

3. joins greater petrosal n to become nerve of the pterygoid canal

4. post gang fibers pass thru pterygopalatine ganglion to distribute w/ V2 thruout nasal cavity