Nose, Nasal cavity, Nose, Nasal cavity, Paranasal Sinuses & PharynxParanasal Sinuses & Pharynx

ObjectivesObjectives

At the end of the lecture, the students should be At the end of the lecture, the students should be able to:able to:

Describe the boundaries of the nasal cavity.Describe the boundaries of the nasal cavity. Describe the nasal conchae and meati.Describe the nasal conchae and meati. Demonstrate the openings in each meatus.Demonstrate the openings in each meatus. Describe the paranasal sinuses and their functionsDescribe the paranasal sinuses and their functions Describe the pharynx and its partsDescribe the pharynx and its parts

NoseNoseroot

tip

external naresseptum

ala

The The external external (anterior ) nares (anterior ) nares oror nostrils nostrils, , lead lead to the to the nasal nasal cavity.cavity.

Formed above by:Formed above by:

Bony skeletonBony skeleton

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belowbelow by by plates of plates of hyaline hyaline cartilagecartilage..

Nasal CavityNasal Cavity

Extends from the Extends from the external (anterior) external (anterior) nares nares to the to the posterior nares posterior nares (choanae).(choanae).

Divided into right Divided into right & left halves by & left halves by the the nasal septum.nasal septum.

Each half has a:Each half has a: RoofRoof Lateral wallLateral wall Medial wall Medial wall

(septum)(septum) FloorFloor

RoofRoof Narrow & formed (from Narrow & formed (from

behind forward) by the: behind forward) by the:

1.1. Body of sphenoid.Body of sphenoid.

2.2. Cribriform plate of Cribriform plate of ethmoid bone.ethmoid bone.

3.3. Frontal bone.Frontal bone.

4.4. Nasal bone & Nasal bone & cartilagecartilage

FloorFloor• Separates it from the oral cavity. Separates it from the oral cavity. • Formed by the Formed by the hard (bony) palate.hard (bony) palate.

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Medial Wall Medial Wall (Nasal Septum)(Nasal Septum)

OsteocartilaginousOsteocartilaginous partition.partition.

Formed by:Formed by:1.1. Perpendicular Perpendicular

plate of plate of ethmoid bone.ethmoid bone.

2.2. VomerVomer..3.3. Septal Septal

cartilage.cartilage.

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Lateral WallLateral Wall

Shows three horizontal Shows three horizontal bony projections, the bony projections, the superiorsuperior,, middlemiddle && inferiorinferior conchaeconchae

The cavity below each concha is called a The cavity below each concha is called a meatusmeatus and and are named as are named as superiorsuperior, , middlemiddle & & inferiorinferior corresponding to the conchae.corresponding to the conchae.

The small space above the superior concha is the sphenoethmoidal recess.sphenoethmoidal recess.

The The conchaeconchae increase the increase the surface area of the surface area of the nasal cavity.nasal cavity.

TheThe recess recess & & meatimeati receive the receive the openings of the:openings of the: Paranasal Paranasal

sinuses.sinuses. Nasolacrimal Nasolacrimal

duct.duct.

Spheno Spheno ethmoidethmoidal recessal recess

sphenoidal sinussphenoidal sinus

Superior Superior meatusmeatus

posterior ethmoidal sinusposterior ethmoidal sinus

Middle Middle meatusmeatus

middle ethmoidal, middle ethmoidal, maxillary, maxillary, frontal &frontal &the anterior ethmoidal the anterior ethmoidal sinuses sinuses

Inferior Inferior meatusmeatus

nasolacrimal duct.nasolacrimal duct.

Nerve Nerve SupplySupplyOlfactory Olfactory

mucosamucosa supplied supplied by by olfactory olfactory nerves.nerves.Nerves of Nerves of general general sensation are sensation are derived fromderived from• ophthalmicophthalmic• maxillary maxillary nerves.nerves.• Autonomic Autonomic fibers.fibers.

Blood supply Blood supply Arterial Supply: Arterial Supply: Branches of theBranches of the• maxillary, maxillary, • facial & facial & • ophthalmic arteries.ophthalmic arteries. The arteries make a The arteries make a

rich anastomosis in rich anastomosis in the region of the the region of the vestibule, and anterior vestibule, and anterior portion of the septum.portion of the septum.

Venous DrainageVenous Drainage:: drain into the drain into the • facialfacial, , • ophthalmicophthalmic, and , and • spheno-palatine veins. spheno-palatine veins.

LymphaticLymphatic DrainageDrainage

The lymphatics The lymphatics from the:from the:

Vestibule Vestibule drains drains into the into the submandibularsubmandibular lymph nodes.lymph nodes.

Rest of the Rest of the cavity cavity drains drains into the into the upper upper deep cervicaldeep cervical lymph nodes. lymph nodes.

Paranasal SinusesParanasal Sinuses Air filled cavities Air filled cavities located in the located in the

bones around the nasal cavity: bones around the nasal cavity: ethmoid, sphenoid, frontal bones ethmoid, sphenoid, frontal bones & maxillae.& maxillae.

Lined by respiratory mucosa Lined by respiratory mucosa which is continuous with the which is continuous with the mucosa of the nasal cavity.mucosa of the nasal cavity.

Drain into the nasal cavity.Drain into the nasal cavity.

FunctionsFunctions Lighten the skull.Lighten the skull. Act as resonant chambers for Act as resonant chambers for

speech.speech. Air conditioning: Air conditioning: The respiratory The respiratory

mucosal lining helps in warming, mucosal lining helps in warming, cleaning and moistening the cleaning and moistening the incoming air.incoming air.

PharynxPharynx Muscular tube lying behind the Muscular tube lying behind the

nosenose, , oral cavity oral cavity & & larynx.larynx. Extends Extends from the base of the from the base of the

skull to level of the 6skull to level of the 6thth cervical cervical vertebravertebra, where it is , where it is continuous with the esophaguscontinuous with the esophagus

The anterior wall is deficient The anterior wall is deficient and shows (from above and shows (from above downward):downward): Posterior nasal apertures.Posterior nasal apertures. Opening of the oral cavity.Opening of the oral cavity. Laryngeal inlet.Laryngeal inlet.

The muscles arranged in The muscles arranged in circularcircular and and longitudinal layers.longitudinal layers.

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oc

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Circular (Constrictor) MusclesCircular (Constrictor) Muscles

Functions: Functions: Propel the bolus of food down into the esophagus.Propel the bolus of food down into the esophagus. lower fibers of the inferior constrictor (lower fibers of the inferior constrictor (CricopharygeusCricopharygeus) act ) act

as a sphincter, preventing the entry of air into the as a sphincter, preventing the entry of air into the esophagus between the acts of swallowing. esophagus between the acts of swallowing.

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Three in number: Three in number: • Superior constrictorSuperior constrictor,,• Middle constrictorMiddle constrictor & & • Inferior constrictorInferior constrictor The three muscles overlap The three muscles overlap

each other.each other.

Longitudinal MusclesLongitudinal Muscles

Three in number: Three in number: • StylopharyngeusStylopharyngeus• SalpingopharyngeusSalpingopharyngeus• PalatpharyngeousPalatpharyngeous

Function: Function: Elevate the larynx & Elevate the larynx &

pharynx during pharynx during swallowingswallowing

Pharynx is divided Pharynx is divided into three parts:into three parts: NasopharynxNasopharynx. . OropharynxOropharynx. . LaryngopharynxLaryngopharynx..

NasopharynxNasopharynx Extends from the base of skull to Extends from the base of skull to the soft palate.the soft palate.

communicates with the nasal communicates with the nasal cavity through cavity through posterior nasal posterior nasal aperturesapertures

Pharyngeal tonsils (adenoides) Pharyngeal tonsils (adenoides) present in the submucosa present in the submucosa covering the roof.covering the roof.

Lateral wall shows:Lateral wall shows: Opening of auditory tube.Opening of auditory tube. Tubal elevation (produced by Tubal elevation (produced by

posterior margin of the posterior margin of the auditory tube).auditory tube).

Tubal tonsil.Tubal tonsil. Salpingopharyngeal fold Salpingopharyngeal fold

(raised by salpingo-(raised by salpingo-pharyngeus muscle).pharyngeus muscle).

OropharynxOropharynx Lies behind the mouth, Lies behind the mouth, communicates with the communicates with the oral cavity through theoral cavity through the oropharyngeal isthmusoropharyngeal isthmus

Extends from Extends from soft soft palate palate toto upper border upper border of epiglottis.of epiglottis.

Lateral wallLateral wall shows: shows: Palatopharyngeal Palatopharyngeal

folds.folds. Palatine tonsil Palatine tonsil

located between located between them in them in a depression called a depression called the the ‘tonsillar fossa’. ‘tonsillar fossa’.

Palatoglossal fold

Palato-pharyngeal fold Tonsillar fossa

LaryngopharynxLaryngopharynx Lies behind the laryngeal inlet & the Lies behind the laryngeal inlet & the

posterior surface of larynx.posterior surface of larynx. communicates with the larynx through communicates with the larynx through

the the laryngeal inletlaryngeal inlet Extends from Extends from upper border of epiglottis upper border of epiglottis

to to lower border of cricoid cartilage.lower border of cricoid cartilage. A small depression situated on either A small depression situated on either

side of the laryngeal inlet is called side of the laryngeal inlet is called ‘‘piriform fossa’.piriform fossa’.

It is a common site for the lodging of It is a common site for the lodging of foreign bodies.foreign bodies.

Branches of internal laryngeal (& Branches of internal laryngeal (& recurrent laryngeal) nerve lie deep to recurrent laryngeal) nerve lie deep to the mucous membrane of the fossa the mucous membrane of the fossa and are vulnerable to injury during and are vulnerable to injury during removal of a foreign body.removal of a foreign body.

Nerve SupplyNerve Supply Sensory:Sensory:

• NasopharynxNasopharynx: : Maxillary Maxillary nervenerve

• OropharynxOropharynx: : Glossopharyngeal nerveGlossopharyngeal nerve

• LaryngopharynxLaryngopharynx: : Vagus Vagus nervenerve

Motor Nerve Supply:Motor Nerve Supply:• All the muscles of All the muscles of

pharynx are supplied by pharynx are supplied by

the the pharyngeal pharyngeal plexus. plexus.

• except ;except ; the the Stylopharyngeus is Stylopharyngeus is supplied by the supplied by the glossopharyngeal nerve glossopharyngeal nerve

Arterial supplyArterial supply: : From From branches of:branches of:

Ascending pharyngeal arteryAscending pharyngeal artery Ascending palatine arteryAscending palatine artery Facial arteryFacial artery Maxillary arteryMaxillary artery Lingual arteryLingual artery

TheThe VeinsVeins drain into drain into pharyngeal venous plexus, pharyngeal venous plexus, which drains into the internal which drains into the internal jugular veinjugular vein

The The lymphaticslymphatics drain into the drain into the deep cervical lymph deep cervical lymph nodes nodes either directly, or indirectly via either directly, or indirectly via the the retropharyngealretropharyngeal or or paratracheal lymph nodesparatracheal lymph nodes

Thank You & Good Luck