The nasal cavity

The external nose

• Parts:– Root, dorsum or bridge, tip, alae, base, nares

( nostril) separated by the septum

• Nerves

• Motor, facial to muscles

• Sensory, to infratrochlear from nasociliary br. Of ophthalmic(V) to skin of root, alae, nostril; infraorbital br. To maxillary(V) to sides of nose

Blood vessels

• Vessels:

• Arteries: facial to side, alae, septum; dorsal nasal br. Of ophthalmic to root and dorsum; infraorbital branch of maxillary to sides.

• Veins, drain into ophthalmic and anterior facial vein.

Woodruff's plexus:• Is responsible for posterior bleeds. • This area is located over the posterior end of the middle turbinate. • The anastomosis here is made up of branches from the internal

maxillary artery namely its sphenopalatine and ascending pharyngeal branches.

• The maxillary sinus ostium forms the dividing line between the anterior and posterior nasal bleeds.

• Posterior nasal bleeds are difficult to treat because bleeding area is not easily accessible.

• Bleeding from Woodruff's plexus commonly occur in patients with extremely high blood pressure. Infact this plexus acts as a safety valve in reducing the blood pressure in these patients, lest they will bleed intracranially causing more problems.

• In patients with posterior bleeds it is difficult to access the amount of blood loss because most of the blood is swallowed by the patient.

• Etiology: The etiology of epistaxis is not just simple or straight nasal bleeding.

Framework

• Hyaline cartilage– Septal, between right and left nasal cavities,

attachment: perpendicular plate of ethmoid, vomer, maxilla, nasal, septal process of lower nasal passages.

– Lateral nasal ( upper lateral), attached to nasal bone, frontal process of axilla, lower nasal cartilage continuous with septal cartilage.

Framework:

• Hyaline cartilage

– Greater alar (lower lateral alar), • U shaped, open posteriorly, has medial and lateral

crura.• Medial crura attach with each other and upper

nasal cartilage.

– Lesser alar.

Boundaries :

• Bones:– 2 nasal bones– Frontal process of

maxillae

Nasal cavities

• Separated by nasal septum into L and R cavities.

• Anterior aperture: ( nares) open into:– Vestibule, a dilated area bounded by ala and

crus of nasal cartilage.

Boundaries of nasal cavities

• Roof = frontonasal, ethmoidal, sphenoidal

• Floor = wider, formed by palatine process

• Medial wall = nasal septum• Lateral wall = nasal conchae, irregular

• Conchae = form a meatus, a passage of the nasal cavity

Nasal conchae

• 4 passages

• Sphenoethmoidal recess

• Superior meatus• Middle meatus

• Inferior meatus

Nasal cavities

• Lateral wall: division created by the nasal conchae:– Sphenoethmoidal recess, above superior

concha– Superior meatus, below superior concha,

above middle concha.– Middle meatus, below lateral to middle

concha, above inferior concha.– Inferior meatus, below and lateral to middle

concha above palate.

Cavities

• Openings into the meatus or recesses:– Sphenoethmoidal recess: sphenoidal sinis– Superior meatus: posterior ethmoidal air cells

– Middle meatus:• Anteriorly, forntonasal duct, ant. Ethmoidal air cells• post.: ostium from maxillary sinus• On or above bulla: middle ethmoidal air cells

– Inferior meatus: naso lacrimal duct

Nasal cavities

• Medial wall: recess, spaces, or hiatus– Nasopalatine recess: depression in septum

over incisive canal.– Vomeronasal organ

• Posterior aperture: 2 choanae opening into nasopharynx.

Nasal cavity

• Anterior aperture: pear shaped, bounded by nasal bone and anterior border of maxillae.

• Boundary:– Medial (septal) wall

• Septal cartilage• Perpendicular plate of ethmoid• Vomer• Projections of other bones :palatine, maxillary,

frontal, nasal, sphenoid.

Nasal cavity

• boundary:– Lateral wall:

• Superior and middle conchae ( turbinates) of ethmoid.• Inferior conchae ( turbinate)• Nasal bone• Frontal process and nasal surface of maxilla• Lacrimal bone• Perpendicular plate of palatine.• Medial pterygoid plate and body of sphenoid.• Inferior & middle conchae project medially & inferiorly

Nasal cavity

• Roof– Upper nasal cartilage– Nasal bone– Spine of frontal bone– Cribriform plate of ethmoid bone.– Body of sphenoid bone

• Floor – Palatine process of maxilla– Horizontal plate of palatine bone.– Posterior choanae opens into the nasopharynx.

Vasculature and innervation

• Sphenopalatine artery• Anterior and posterior ethmoidal arteries• Greater palatine artery• Superior labial artery • Lateral nasal branches of facial arteryNerve• Maxillary nerve = to posteroinferior half by

nasopalatine and greater palatine• Nasocilliary nerve = via the anterior and

posterior ethmoidal nerves

Clinical

• Deviated septum• Rhinitis is an inflammation of the nasal mucous

membrane ( nasal catarrh)• Nasal polyp, a focal submucosal thickening due

to edema, pinkish gray and edematous and may attain a large size.

• Rhinorrhea, discharge from nasal mucous membrane.– CSF rhinorrhea, fracture of cribriform plate, tearing of

meninges.

Clinical

• Fracture of the nose:

• Common and usually transverse.

• Caused by a direct blow, the horizontal plate of ethmoid is often fractured.

Causes of epistaxis:

1. Vascular anamolies2. Infections and inflammatory

states of the nasal cavity,3. Trauma4. Iatrogenic injuries5. Neoplasms and foreign bodies.• a. infection • b. inflammation of mucosa6. Chronic granulomatous lesions7. Rhinosporidiosis8. Anatomical deformities 9. Septal perforations

Epistaxis• To manage post nasal bleed a post nasal pack is a must. Post nasal packing

can be done in 2 ways:• Post nasal packing (conventional): A gauze roll about the size of the patient's

naso pharynx is used here. Three silk threads must be tied to the gauze roll. One at each end and the other one at the middle. The patient should be in a recumbent position. After anesthetising the nasal cavity with 4% xylocaine the mouth is held open. Two nasal catheters are passed through the nasal cavities till they reach just below the soft palate. These lower ends of the catheters are grasped with forceps and pulled out through the mouth. The silk tied to the ends of the gauze is tied to the nasal catheters. The post nasal pack is introduced through the mouth and gradually pushed into the nasopharynx, at the same time the nasal catheters on both sides of the nose must be pulled out. When the pack snugly sits inside the nasopharynx, the two silk threads tied to its end would have reached the anaterior nares along with the free end of the nasal suction catheter.

Epistaxis management

• Problems of nasal packing:

1. Epiphora (watering of eyes) occur due to blocking of the nasal end of the nasolacrimal duct.

2. Heaviness /headache due to blocking of the normal sinus ostium.

3. Prolonged post nasal pack can cause eustachean tube block and secretory otitis media.

4. Prolonged nasal packing can cause secondary sinusitis due to blockage of sinus ostium.

Application of Nasal pack

Mucous membrane

• Divisions: vestibule, respiratory area, olfactory area.

• Structure:– Vestibule, skin turned in at nares with coarse hairs

and sebaceous glands.– Olfactory, over sup. Concha, roof, upper 3rd of

septum, thick epithelial layer with supporting and olfactory cells

– Respiratory: covers remainder of nasal cavity, continuous into sinuses. Epithelium is pseudostratified columnar ciliated with goblet cells.

Paranasal sinuses• Air filled extensions of the nasal cavities

lined with mucous membrane.– Frontal, behind supercillary ridges of frontal

bone, divided by septum, drains into frontonasal duct thru rostral ethmoidal cells to middle meatus

– Ethmoidal, aggregations of thin walled spaces in ethmoidal labyrinth between orbit and nasal cavities in 3 sets. Drainage:

• Anterior into infundibulum of middle meatus• Middle, above ethmoid bulla in mid meatus• Posterior, into superior meatus, to sphenoid sinus.

Paranasal sinuses

• Sphenoidal sinus– Located at body of sphenoid, divided by

septum. Drain into sphenoidal recess.

• Maxillary sinus ( largest)– Located at body of maxilla, roofed by orbit,

wall of nasal cavity is medial, alveolar process is lateral and sinus extends to zygoma.

– Drain into semilunar hiatus of mid meatus.

Blood and nerve supply• Supraorbital artery & nerve, major suppliers of

frontal sinus.• Anterior & posterior ethmoidal vessels & nerves,

orbital branch of pterygopalatine ganglia.

• Posterior ethmoidal vessels & nerves & orbital branch of pterygopalatine ganglia supply the sphenoidal sinus.

• Branches of ant.post, mid, superior alveolar and infraorbital nerve supply to maxillary sinus.

• Vessels are: facial, infraorbital, greater palatine.

Clinical

• Mucous membrane, motile cilia and rich blood supply, adapt to purifying, moistening and warming air to protect the lungs.

• Sinuses are effectively making the head lighter.

Disadvantage

• Numerous connections to nasal cavities prone to easy infections.

• Swelling of nasal mucosa around orifice slows discharge• Maxillary & sphenoid, largest portion of sinus lie below

opening into nose, making drainage difficult.• Proximity of maxillary sinus to root of upper teeth, to

distinguish, sinusitis from toothache is difficult.• Thin bone separating meninges and sinuses making a

good chance for infection of meninges.• Sinusities, an inflammation of the mucousa of one or

more accessory nasal sinuses & maybe acute or chronic.

Arteries of the nose

• Anterior ethmoidal– Origin = ophthalmic – Distribution = lateral

wall and septum, dorsolateral external surface of nose.

• Posterior ethmoidal– Origin, ophthalmic– Distribution, ethmoidal

sinus, lateral wall, septum of nose

• Sphenopalatine– Origin = 3rd part of maxillary– Distri = posterior lateral

nasal branches to conchae, meatus

– Posterior septal branches to nasal septum

• Greater palatine– 3rd part maxillary– Distri = to septum

• Septal, alar branches – Origin = superior labial

branch of facial– Distri = rostral inferior

septum and vestibule– Source of nose bleeding

especially in children.

Clinical

• Injuries to membrane lead to profuse bleeding. If bleeding are severe in posterior end of mid conchae and roof of nose, ligation of external carotid or ethmoidal artery is necessary.

• Epistaxis, nose bleeding, due to broad anastomosis of the major arteries in the anterior lower portion of nasal septum.

• Bleeding at the back end of middle conchae, sphenopalatine artery is involved, packing is therapeutic.

• Bleeding from roof of the nasal cavity comes from ethmoidal arteries.

Nerves of nasal cavity

• Special sensory:– Olfactory (1) nerve of smell– Receptor: neuroepithelial cells of olfactory

mucosa lie on the upper 3rd of nasal septum

• General sensory:– Ophthalmic div, of Trigeminal nerve(V),

nasociliary to anterior of nasal septum and lateral wall, to cutaneous tip of nose.

A. Maxillary/mandibular nerveB. Sphenopalatine ganglion

• General sensory

• Maxillary division– Pterygopalatine nerves.

• Greater palatine nerve. To the inferior nasal concha, inferior and middle meatus.

• Posterior superior nasal branches to superior and middle conchae. Nasopalatine nerve to incisive canal.

– Anterior superior alveolar nerve to rostral part of inferior meatus and floor of nasal cavity

• Motor: autonomic system distributed to the glands and blood vessels of the mucous membrane– Craniosacral division (parasympathetic)

• Preganglionic fibers from superior salivatory nucleus of the Pons via nervus intermedius and greater petrosal nerve to pterygopalatine ganglion.

• Postganglionic fibers from cells in the pterygopalatine ganglion to the pterygopalatine nerves.

• Motor: – Thoracolumbar (sympathetic)– Preganglionic fibers from intermediolateral

gray column of upper thoracic to the superior cervical ganglion.

– Postganglionic fibers from cells in the superior cervical ganglion to form the nerve of the pterygoid canal.

Cranial nerves

Motion Superior oblique of eye

Nucleus in floor of cerebral aqueduct

IV Trochlear

Motor

Motion Sup, inf, med, recti; inf oblique ciliaris; sphincter pupillae mm.

Nucleus in floor of cerebral aqueduct

III Oculomotor

Motor

Sense of sight

Retina of eye

Ganglionic cells of retina

II Optic

Sensory

Sense of smell

Nasal mucous membrane

Central / deep process of olfactory bulb

I Olfactory

sensory

Function DistributionNuclei origin & termination

Name

Sense of hearing

Sense of equilibrium

To organ of corti

To semicircular canal

Cochlear, bipolar spiralganglion

Vestibular, bipolar veswtibular ganglion

VIII Acoustic

Sensory

Taste

Gen. sensation

secretion

Ant.2/3 tongue,mid ear,Face, scalp, auricle,neck, sublingual gland

Sensory from geniculate ganglion

Motor from pons, sup. Salivatory nucleus

VII Facial

Mixed

Motion Lat. Rectus of eye

4th ventricleVI Abducens

Motor

Sensation

Sensation

Ophthto cornea, ciliary BD,iris, lacrimal gld, eye, nose. Max. to nose

Mandibular to ear, mastication, tongue

Sensory from semilunar ganglion

Motor from pons

V Trigeminal

Mixed

Function DistributionNuclei origin & termination

Name

Motion Muscles of tongueHypoglossal nuc. medulla

XII Hypoglossal

Motor

Motion

Motion

To pharyngeal laryngeal brs. Of vagus to pharynx & larynx

To sternocleidomastoid & trapezius

Cranial from nuc. Ambiguus

Spinal: spinal cord C5

XI Accessory

Cranial, spinal

Sensation

Motion

Secretion

Mucus membrane larynx, trachea, lungs, esophagus, stomach, SI, LI, larynx, esopha.

Stom, excitatory fibers

Gastric,pancreatic gld.

Sensory from sup. Gang. Inf gang. Nodosum

Motor from nuc ambiguus n medulla

X Vagus

Mixed

Taste

Gen. sense of motion

Secretion

Mucus membrane of fauces, tonsils, pharynx, post 1/3 tongue, pharynx, secretory fibers of parotid

Sensory from inf. Ganglion, nucleus ambiguus & inf. Salivatory nucleus

IX Glosso pharyngeal

Mixed

Function DistributionNuclei origin & termination

Name

12 CRANIAL NERVES

• Oh , Oh, Oh, To, Taste, A, Female, And,

Glossy, Vagina, Ah, Heaven.

CN 1 Olfactory , sCN 2 Optic , sCN 3 Oculomotor , mtrCN 4 Trochlear , mtrCN 5 Trigeminal , mxdCN 6 Abducens , mtrCN 7 Facial , mxdCN 8 Acoustic , s CN 9 Glossopharyngeal

,mxdCN 10 Vagus , mxdCN 11 Accessory , spinalCN 12 Hypoglossal , Mtr

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