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

ObjectivesObjectives

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

septum

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Nose, is the only visible part of the respiratory system and serves as the entrance to the respiratory tract

The nose has two cavities, separated from one another by a wall called the septum.

The external openings, known as external (anterior) nares external (anterior) nares oror nostrils,nostrils, lead to the lead to the nasal nasal cavities.cavities.

Formed: above by bony skeleton & below by plates of hyaline

cartilage.

Nasal CavityNasal Cavity

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

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

Each half has a:Each half has a: RoofRoof Lateral wallLateral wall Medial wall (septum)Medial wall (septum) FloorFloor

RoofRoof Narrow & formed Narrow & formed

(anteroposteriorly) by (anteroposteriorly) by the: the:

1.1. Nasal bone & Nasal bone & cartilagecartilage

2.2. Frontal bone.Frontal bone.

3.3. Cribriform plate of Cribriform plate of ethmoid boneethmoid bone

4.4. Body of sphenoid.Body of sphenoid.

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

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Hard PalateHard Palate

Oral cavityOral cavity

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

Osteo-Osteo-cartilaginouscartilaginous partition between partition between the two nasal the two nasal cavities.cavities.

Formed by:Formed by:1.1. Septal cartilage.Septal cartilage.2.2. Perpendicular Perpendicular

plate of ethmoid plate of ethmoid bone.bone.

3.3. VomerVomer..

Lateral WallLateral Wall Shows three horizontal Shows three horizontal

bony projections, the bony projections, the superiorsuperior,, middlemiddle && inferiorinferior conchae.conchae.

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

The small space above The small space above the superior concha is the superior concha is the the sphenoethmoidal sphenoethmoidal (suprameatal) recess.(suprameatal) recess.

The conchae are covered by The conchae are covered by respiratory epithelium and thus respiratory epithelium and thus

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

Inferior concha

Inferior concha

SuperiorSuperior conchaconcha

middle concha

middle concha

Sphenoethmoidal Sphenoethmoidal recessrecessMeatiMeati

SphenoethmoidaSphenoethmoidal recessl recess

sphenoidal sinussphenoidal sinus

Superior meatusSuperior meatus posterior ethmoidal sinusposterior ethmoidal sinus

Middle meatusMiddle meatus middle ethmoidal, maxillary, frontal & the middle ethmoidal, maxillary, frontal & the anterior ethmoidal sinusesanterior ethmoidal sinuses

Inferior meatusInferior meatus nasolacrimal duct.nasolacrimal duct.

The recess & meati receive the openings of the paranasal sinuses & naso-lacrimal duct.

Nerve SupplyNerve Supply Olfactory Olfactory

mucosamucosa supplied by supplied by olfactory olfactory nerves.nerves.

Nerves of Nerves of general general sensation are sensation are derived from derived from ophthalmicophthalmic & & maxillary maxillary nerves.nerves.

Autonomic Autonomic fibers.fibers.

Arterial Supply: Arterial Supply: Branches of Branches of

the maxillary, the maxillary, facial & facial & ophthalmic ophthalmic arteries.arteries.

The arteries The arteries make a rich make a rich anastomosis in anastomosis in the region of the region of the vestibule, the vestibule, and anterior and anterior portion of the portion of the septum.septum.

Venous DrainageVenous Drainage:: By the: By the: facialfacial ophthalmicophthalmic and and spheno-palatine veins. spheno-palatine veins.

LymphaticLymphatic DrainageDrainage:: To the To the submandibularsubmandibular and and

the the upper deep cervicalupper deep cervical lymph nodes. lymph nodes.

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

the bones around the nasal the bones around the nasal cavity (cavity (ethmoid, sphenoid, ethmoid, sphenoid, frontal bones & maxillaefrontal bones & 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 speech.Act as resonant chambers for speech. Air conditioning: Air conditioning: The respiratory mucosal lining helps The respiratory mucosal lining helps

in warming, cleaning and moistening the incoming in warming, cleaning and moistening the incoming air.air.

PharynxPharynx Muscular tube lying behind the Muscular tube lying behind the nasal cavitynasal cavity, , oral cavity oral cavity & & larynx.larynx. Extends Extends from the base of the skull to level of the 6from the base of the skull to level of the 6thth cervical vertebra cervical vertebra, ,

where it is continuous with the esophaguswhere it is continuous with the esophagus

Nasal cavity

larynx

Naso-Naso-pharynxpharynx

Oro-Oro-pharynxpharynx

Laryngo-Laryngo-pharynxpharynx

EsophagusEsophagus

Oral cavity

Divided into three parts:Divided into three parts: NasopharynxNasopharynx: :

Superior part, communicates Superior part, communicates with the nasal cavity through with the nasal cavity through posterior nasal aperturesposterior nasal apertures

OropharynxOropharynx: : Middle part, communicates with Middle part, communicates with

the oral cavity through thethe oral cavity through the oro-oro-pharyngeal isthmuspharyngeal isthmus

LaryngopharynxLaryngopharynx: : Inferior part, communicates with Inferior part, communicates with

the larynx through the the larynx through the laryngeal laryngeal inletinlet

NasopharynxNasopharynx Extends from the base of Extends from the base of

skull to the soft palate.skull to the soft palate. Contains Contains Pharyngeal tonsils Pharyngeal tonsils

(adenoides) in its roof.(adenoides) in its roof. Lateral wall shows:Lateral wall shows:

Opening of Opening of auditory auditory tube.tube.

Tubal elevation Tubal elevation (produced by posterior (produced by posterior margin of the auditory margin of the auditory tube).tube).

Tubal tonsil.Tubal tonsil. Salpingopharyngeal fold Salpingopharyngeal fold

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

Pharyngeal tonsil

Tubal tonsil

Tubal elevation

Salpingo-pharyngeal fold

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OropharynxOropharynx Extends from Extends from soft soft

palate palate toto upper border upper border of epiglottis.of epiglottis.

Lateral wallLateral wall shows:shows: Palatoglossal foldPalatoglossal fold Palatopharyngeal Palatopharyngeal

fold.fold. Palatine tonsil Palatine tonsil

located in located in ‘tonsillar ‘tonsillar fossa’, fossa’, a a depression depression between the two between the two foldsfolds

Palatoglossal fold

Palatopharyngeal fold

Palatine tonsil in tonsillar fossa

LaryngopharynxLaryngopharynx

Extends from Extends from upper border of upper border of epiglottis epiglottis to to lower border of lower border of cricoid cartilage.cricoid cartilage.

Piriform fossa Piriform fossa A small depression situated on A small depression situated on either side of the laryngeal inleteither side of the laryngeal inletIt is a It is a common site common site for the lodging for the lodging of foreign bodies.of foreign bodies.Branches of internal laryngeal & Branches of internal laryngeal & recurrent laryngeal nerves lie deep recurrent laryngeal nerves lie deep to the mucous membrane of the to the mucous membrane of the fossa and are vulnerable to injury fossa and are vulnerable to injury during removal of a foreign body.during removal of a foreign body.

Muscles of PharynxMuscles of Pharynx

MM

SS

II

The muscles of the pharynx are arranged in circular and longitudinal layers

Circular (Constrictor) Three muscles, overlap each Three muscles, overlap each

other: other: SuperiorSuperior, , MiddleMiddle & & InferiorInferior Propel the bolus of food down

into the esophagus

Longitudinal Muscles Three muscles: Three muscles:

Stylopharyngeus Salpingopharyngeus Palatpharyngeous

Elevate the larynx & pharynx during swallowing

Sensory Sensory Nerve SupplyNerve Supply• NasopharynxNasopharynx: : Maxillary nerveMaxillary nerve• OropharynxOropharynx: : Glossopharyngeal nerveGlossopharyngeal nerve• LaryngopharynxLaryngopharynx: : Vagus nerveVagus nerve

MotorMotor Nerve Supply Nerve Supply : : • All the muscles of pharynx, except the stylopharyngeus, are supplied All the muscles of pharynx, except the stylopharyngeus, are supplied

by the by the pharyngeal plexus. pharyngeal plexus. • Stylopharyngeus is supplied by the Stylopharyngeus is supplied by the glossopharyngeal nerve glossopharyngeal nerve

Pharyngeal plexusA network of nerves (sensory, motor & sympathetic) located on the surface of the middle pharyngeal constrictor muscle, is formed by the:

• Pharyngeal branches of glossopharyngeal nerve (sensory)• Pharyngeal branch of vagus nerve (motor)• Sympathetic fibers from superior cervical ganglion (vasomotor)

Arterial supplyArterial supply: : From branches of:From 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 plexuspharyngeal venous plexus, which , which drains into the drains into the internal jugular veininternal jugular vein

TheThe LymphaticsLymphatics drain into the: drain into the: Deep cervicalDeep cervical Retropharyngeal &Retropharyngeal & Paratracheal lymph nodesParatracheal lymph nodes

Thank You & Good Luck