1. Nasal cavity Boundaries of the nasal cavity: Roof: formed by:
Frontal and nasal bones, anteriorly
Cribriform plate of ethmoid, in the middle
Body of sphenoid, posteriorly
Floor: upper surface of hard palate
Lateral wall: formed by:
Nasal surface of ethmoid labyrinth, superiorly
Perpendicular plate of palatine bone, posteriorly
Nasal surface of maxilla, lower and anterior part.
Frontal bone
Cribriform plate of ethmoid
Body of sphenoid
Nasal bone
Ethmoid labyrinth
Inferior concha
Nasal surface
of maxilla
Hard palate
Perpendicular plate
of palatine bone

2. Medial wall (nasal septum): formed by:
Perpendicular plate of ethmoid, superiorly
Vomer, posteriorly and inferiorly
Septal cartilage, anteriorly and inferiorly
Crista galli
Perpendicular plate
of ethmoid
Septal
cartilage
V o m e r

3. Features of the lateral wall of the nose
Nasal conchae:
Three bony elevations on the lateral wall (superior, middle and inferior conchae)
A highest nasal concha is sometimes present
The superior and middle conchae are parts of the ethmoid labyrinth
The inferior concha is a separate bone
Superior
nasal concha
Highest nasal
concha
Middle nasal concha
Inferior nasal concha

4. Nasal meatuses:
The depressions below the conchae are called meatuses (superior, middle and inferior)
The depression between the roof and superior concha is called the sphenoethmoidal recess
Sphenoethmoidal recess
Superior nasal meatus
Middle nasal meatus
Inferior nasal meatus

5. Features of the middle meatus:
Bulla ethmoidalis: a bulging on the lateral wall of middle meatus
Hiatus semilunaris: a crescentic groove below the bulla ethmoidalis
Infundibulum: a recess at the anterior end of hiatus semilunaris
Bulla ethmoidalis
Infundibulum
Hiatus semilunaris

6. Openings into the lateral wall of nasal cavity:
Sphenoidal air sinus: opens into the sphenoethmoidal recess
Posterior ethmoidal sinuses: open into the superoir meatus
Middle ethmoidal sinuses: open into the middle meatus above the bulla ethmoidalis
Maxillary sinus: opens into the hiatus semilunaris
Anterior ethmoidal sinuses: open into the anterior part of hiatus semilunaris
Frontal sinus: opens into the infundibulum (through the frontonasal duct)
Nasolacrimal duct: opens into the anterior part of the inferior meatus
Opening of sphenoidal sinus
Frontonasal duct
Openings of post
ethmoidal cells
Openings of middle
ethmoidal cells
Openings of anterior
ethmoidal cells
Opening of nasolacrimal duct
Opening of maxillary sinus

7. Areas covered by olfactory mucosa
Nasal mucosa:
The nasal mucosa is differentiated into:
Olfactory mucosa: covering the roof and upper parts of lateral and medial walls It contains the olfactory receptor nerve cells (their axons form the olfactory nerves)
Respiratory mucosa: covers the remaining part of the nasal walls. It contains mucous glands and goblet cells
The mucosal lining of the nasal cavity is continuous with:
Mucosa of the nasopharynx: through the posterior nasal apertures
Mucosa of the paranasal sinuses: through their openings
Conjunctiva: through the nsolacrimal duct
Areas covered by olfactory mucosa

8. Anterior septal branch of Posterior septal branch of
Arterial supply of the nose:
Nasal septum:
Posterior septal branch of sphenopalatine a
Anterior septal branch of anterior ethmoidal a (from ophthalmic a)
Septal branch of posterior ethmoidal a (from ophthalmic a)
Septal branch of superior labial artery (from facial a)
Greater palatine artery: from its terminal part
Septal branch
of superior labial a
Septal branches of
post ethmoidal a
Anterior septal branch of
anterior ethmoidal a
Posterior septal branch of
sphenopalatine a
Sphenopalatine a
Greater palatine a

9. Lateral wall: Posterior lateral nasal branches of sphenopalatine a
Anterior lateral nasal branches of anterior ethmoidal a
Lateral nasal branches of posterior ethmoidal a
Greater palatine artery: from its terminal part
Lateral nasal branches of
post ethmoidal a
Anterior lateral nasal branches
of anterior ethmoidal a
Posterior lateral branches
of sphenopalatine a
Greater palatine a
Venous drainage of the nose:
Veins of the nose drain into:
Sphenopalatine vein (maxillary v.)
Opthalmic veins (cavernous sinus)
Facial vein (IJV)

10. Arterial supply of the nose is derived from:
(sphenopalatine, ethmoidal, and facial arteries)
Sphenopalatine artery (from maxillary a), it gives:
Posterior septal nasal
Posterior lateral nasal
Anterior ethmoidal artery (from ophthalmic a), gives:
Anterior septal nasal
Anterior lateral nasal
Posterior ethmoidal artery (from opthalmic a), gives:
Septal nasal
Lateral nasal
Greater palatine artery (from maxillary a), it gives:
Septal nasal branches
Lateral nasal branches
Facial artery, gives:
Septal nasal from its superior labial branch

11. Nerve supply of the nose:
Olfactory sensation:
carried by olfactory nerves from:
The roof
The uppermost parts of the medial and lateral walls
General sensation:
Septum:
Nasopalatine nerve
(from the sphenopalatine ganglion)
Medial internal nasal
(from the anterior ethmoidal nerve)
Lateral wall:
Lateral posterior superior nasal
(from sphenopalatine ganglion)
Lateral posterior inferior nasal
(from greater palatine n)
Lateral internal nasal
(from the anterior ethmoidal n)
Olfactory nerves
Medial internal
nasal n
Sphenopalatine n
Lateral internal
nasal n
Lateral posterior
superior nasal n
Sensory branches of the sphenopalatine ganglion supplying the nasal mucosa carry postganglionic secretomotor fibres from the sphenopalatine ganglion to the nasal glands
Lateral posterior
inferior nasal n

12. Pterygopalatine Fossa
Boundaries:
Ant: posterior surface of maxilla
Post: pterygoid process
Med: perpendicular palatine plate
Lat: pterygomaxillary fissure
Contents:
Maxillary nerve
Third part of maxillary artery
Pterygopalatine ganglion
Communications: the fossa communicates with:
Infratemporal fossa through pterygomaxillary fissure
Middle cranial fossa through foramen rotundum
Nasal cavity through sphenopalatine foramen
Orbital cavity: through inferior orbital fissure
Palate through greater palatine canal
Nasopharynx through pharyngeal and pterygoid canals

13. Sphenopalatine Ganglion
The largest parasympathetic ganglion, located in the pterygopalatine fossa in front of pterygoid canal and below the maxillary nerve
Functionally associated with the facial nerve
Anatomicall associated with the maxillary nerve
Greater petrosal n
Nerve of pterygoid canal
Superior salivary nucleus
Maxillary n
Roots:
Parasymp: greater petrosal N. (facial N)
(fibers originate from the sup salivary nucleus)
Symp: deep ptrosal N.
(fibers originate from the superior cervical sympathetic ganglion and run in the plexus around ICA)
Sensory: maxillary N.
The parasymp and symp roots join each other in the F. lacerum to form the nerve of pterygoid canal which passes through the pterygoid canal to reach the sphenopalatine ganglion
Deep petrosal n
Sphenopalatine ganglion

14. Branches of the sphenopalatine ganglion:
Orbital branches: pass through the inferior orbital fissure to supply orbital periosteum
Palatine branches:
Greater palatine which gives lateral posterior inferior nasal nerves
Lesser palatine
Nasal branches:
Nasopalatine nerve
Lateral & medial posterior superior nasal
Pharyngeal branch: Passes back through the pharyngeal canal to the nasopharynx
Sphenopalatine n
Lateral posterior
sup nasal n
Greater palatine n
Lesser palatine n
Lateral posterior
inf nasal n

15. Postganglionic secretomotor fibers from the sphenopalatine ganglion supply
Lacrimal gland (via zygomatic branch of maxillary nerve)
Nasal glands (via its nasal branches)
Palatine and pharyngeal glands (via its palatine and pharyngeal branches)
Nerve of pterygoid canal
Superior salivary
nucleus
The lesser palatine nerves also carry taste sensations from the palate
Greater petrosal n
Deep petrosal n

17. Anterior, middle & posterior
Paranasal air sinuses
Four in number: frontal, ethmoidal, sphenoidal and maxillary
Lined by respiratory mucosa, containing mucous glands and goblet cells
The mucosal lining is continuous with that of the nose
Functions:
Lightening of the skull
Adding resonance to the voice
Maxillary air sinus
Frontal air sinus:
Lies behind the superciliary arches
Opens into the infundibulum of the nose through the frontonasal duct
Frontal air sinus
Ethmoidal air sinuses:
Occupy the ethmoidal labyrinth
Differentiated into three groups:
1- Anterior: open into the anterior part of hiatus semilunaris
2- Middle: open into the bulla ethmoidalis
3- Posterior: open into the superior meatus
Sphenoidal air sinus:
Occupy the body of sphenoid bone
Opens into into the sphenoethmoidal recess of the nose
Maxillary air sinus:
Occupies the body of maxilla
Opens into the hiatus semilunaris of the nose
Anterior, middle & posterior
ethmoidal air sinuses
Sphenoidal air sinus