Post on 17-Dec-2015
Nose, Nasal cavity Nose, Nasal cavity & &
Paranasal SinusesParanasal Sinuses
NoseNose Only externally visible part Only externally visible part
of the respiratory systemof the respiratory system Has a free Has a free tiptip and is and is
attached to the forehead attached to the forehead by the by the rootroot or the or the bridgebridge
Has two openings, the Has two openings, the anterior (external) nares anterior (external) nares oror nostrils nostrils, , which lead to which lead to the nasal cavitythe nasal cavity
Each nostril is bounded Each nostril is bounded laterally by the laterally by the alaala and and medially by the medially by the nasal nasal septumseptum
root
tip
external naresseptum
ala
Nose: StructureNose: Structure Nose consists of Nose consists of bony bony & &
cartilaginouscartilaginous framework framework Formed Formed aboveabove by the: by the:
• Nasal bonesNasal bones• Frontal processes of Frontal processes of
maxillaemaxillae• Nasal part of frontal Nasal part of frontal
bonebone Formed Formed belowbelow by by plates plates
of of hyaline cartilagehyaline cartilage, , which include which include upperupper & & lowerlower nasal cartilages nasal cartilages and the and the septal septal cartilagecartilage
Nasal part of Frontal bone
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 & Divided into right & left halves by the left halves by the nasal septumnasal septum
Each half has a:Each half has a: FloorFloor RoofRoof Lateral wallLateral wall Medial wall Medial wall
(septum)(septum)
RoofRoof Is narrow & formed Is narrow & formed
(from behind forward) (from behind forward) by the: by the: • Body of sphenoidBody of sphenoid• Cribriform plate of Cribriform plate of
ethmoid boneethmoid bone• Frontal boneFrontal bone• Nasal bone & Nasal bone &
cartilagecartilage FloorFloor
• Separates it from the Separates it from the oral cavity oral cavity
• Formed by the Formed by the hard hard (bony) palate(bony) palate
Medial Wall (Nasal Medial Wall (Nasal Septum)Septum)
OsteocartilaginousOsteocartilaginous partition, only rarely partition, only rarely lying in the midlinelying in the midline
Covered by the Covered by the mucoperiosteummucoperiosteum
Formed:Formed:• SuperiorlySuperiorly by the by the
vertical vertical (perpendicular) plate (perpendicular) plate of ethmoid boneof ethmoid bone
• PosteriorlyPosteriorly by the by the vomervomer bonebone
• AnteriorlyAnteriorly by the by the septal cartilageseptal cartilage
Lateral WallLateral Wall Shows three horizontal Shows three horizontal
bony projections, bony projections, covered by mucous covered by mucous membrane, the membrane, the superiorsuperior,, middlemiddle && inferiorinferior conchae (turbinates)conchae (turbinates)
The The superior and middle superior and middle conchae are parts of the conchae are parts of the ethmoid boneethmoid bone, whereas , whereas the the inferior concha is a inferior concha is a separate boneseparate bone
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 to corresponding to the conchaethe conchae
The small space above The small space above the superior concha is the superior concha is called the called the sphenoethmoidal recesssphenoethmoidal recess
• The middle meatus is The middle meatus is continuous in front with continuous in front with a depression called thea depression called the atriumatrium
• Atrium is limited bove Atrium is limited bove by a ridge calledby a ridge called agar agar nasinasi
• Below and in front of Below and in front of atrium, and just within atrium, and just within the nostril lies thethe nostril lies the vestibulevestibule
The The conchaeconchae increase the surface increase the surface area of the nasal area of the nasal cavitycavity
TheThe recess recess & & meatimeati receive the receive the openings of the:openings of the: Paranasal Paranasal
sinusessinuses Nasolacrimal ductNasolacrimal duct
Sphenoethmoidal Sphenoethmoidal recess:recess: Receives Receives the opening of the the opening of the sphenoidal sinussphenoidal sinus
Superior meatus:Superior meatus: Receives the Receives the opening of the opening of the posterior ethmoidalposterior ethmoidal sinussinus
Inferior meatus:Inferior meatus: Receives the Receives the opening of theopening of the nasolacrimal duct. nasolacrimal duct. The opening is The opening is guarded by a guarded by a valvevalve, , a fold of mucous a fold of mucous membranemembrane
Middle meatus:Middle meatus: • Shows a rounded eminence, Shows a rounded eminence,
the the ethmoidal bullaethmoidal bulla, caused , caused by the bulging of the by the bulging of the underlying underlying middle ethmoidal middle ethmoidal sinussinus, which opens on its , which opens on its upper border.upper border.
• A curved groove, A curved groove, hiatus hiatus semilunarissemilunaris, lies below the , lies below the bulla. Hiatus receives the bulla. Hiatus receives the opening of the opening of the maxillary maxillary sinussinus
• Anterior end of hiatus leads Anterior end of hiatus leads to funnel-shapedto funnel-shaped infundibuluminfundibulum, which receives , which receives the openings of the the openings of the frontal & frontal & thethe anterior ethmoidal anterior ethmoidal sinusessinuses
Lining of the Nasal CavityLining of the Nasal Cavity VestibuleVestibule is lined by is lined by
modified modified skinskin, and has , and has short, curved hair called short, curved hair called vibrissaevibrissae
The The roofroof, , upper part of upper part of the septumthe septum, , upper upper surface of the superior surface of the superior conchaconcha, and the , and the sphenoethmoidal recess sphenoethmoidal recess are lined by the are lined by the olfactory olfactory mucosa mucosa
The The rest of the cavity rest of the cavity is is lined by the lined by the respiratory respiratory mucosamucosa
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Olfactory MucosaOlfactory Mucosa Contains Contains olfactory cells olfactory cells (bipolar sensory (bipolar sensory
ganglion cells), which serve as ganglion cells), which serve as receptors for receptors for olfactory stimuli.olfactory stimuli.
Distinct smells are far more numerous than Distinct smells are far more numerous than tastestastes
The The sense of smell sense of smell plays a major role in the plays a major role in the flavor of foods flavor of foods and it is common for and it is common for individuals who lose their sense of smell to individuals who lose their sense of smell to report that food loses its taste. (food seems report that food loses its taste. (food seems somewhat tasteless when a person has somewhat tasteless when a person has cold)cold)
Most air breathed in normally flows through Most air breathed in normally flows through the nose but only a small part reaches the the nose but only a small part reaches the olfactory mucosa, enough to get a response olfactory mucosa, enough to get a response to an odor. to an odor. SniffingSniffing, however, increases the , however, increases the flow of air over the smell receptor cells, flow of air over the smell receptor cells, greatly increasing their exposure to odors. greatly increasing their exposure to odors.
Respiratory MucosaRespiratory Mucosa Pseudostratified ciliated columnar epithelium Pseudostratified ciliated columnar epithelium
with goblet cellswith goblet cells Rests on Rests on thick network of thin walled veins thick network of thin walled veins that that
warms the air warms the air as it flows through the cavityas it flows through the cavity GlandsGlands produce ‘mucus’, which: produce ‘mucus’, which:
moisten the airmoisten the air cleans the air cleans the air by trapping the incoming by trapping the incoming
bacteria and foreign debrisbacteria and foreign debris Cilia Cilia help in help in moving the contaminated mucus moving the contaminated mucus
posteriorly posteriorly towards the throat, where it is towards the throat, where it is swallowed and digested by the stomach juicesswallowed and digested by the stomach juices
NerveNerve Supply Supply Nasal cavity receives Nasal cavity receives sensorysensory
& & visceralvisceral innervationinnervation
Sensory innervationSensory innervation Olfactory mucosaOlfactory mucosa supplied by supplied by
olfactory nervesolfactory nerves Nerves of general sensation Nerves of general sensation
are derived from are derived from opthalmicopthalmic & & maxillary nervesmaxillary nerves Anterior part Anterior part supplied by the supplied by the
anterior ethmoidal nerve anterior ethmoidal nerve (branch of opthalmic nerve)(branch of opthalmic nerve)
Posterior part Posterior part supplied by supplied by nasalnasal, , nasopalatinenasopalatine and and palatine branches palatine branches (of (of maxillary nerve)maxillary nerve)
Visceral InnervationVisceral Innervation Sympathetic fibers Sympathetic fibers arise arise
from neurons of from neurons of superior superior cervical ganglioncervical ganglion and are and are distributed through distributed through plexuses around the plexuses around the arteriesarteries, supply mainly , supply mainly vascular smooth musclevascular smooth muscle
Parasympathetic fibers Parasympathetic fibers arise arise from neurons of tfrom neurons of the he pterygopalatine ganglionpterygopalatine ganglion that that course in the course in the nasopalatine nasopalatine nervenerve ( (branch of maxillarybranch of maxillary) ) and its branches, supply the and its branches, supply the mucosal glandsmucosal glands. .
Arterial SupplyArterial Supply Sphenopalatine artery Sphenopalatine artery
(branch of the maxillary (branch of the maxillary artery) artery) is the main supplyis the main supply
Alar and septal branches of Alar and septal branches of superior labial artery superior labial artery (branch of the facial artery)(branch of the facial artery)
Anterior & posterior Anterior & posterior ethmoidal arteries ethmoidal arteries (branches of the ophthalmic (branches of the ophthalmic artery)artery)
The arteries make a rich The arteries make a rich anastomosis in the region of anastomosis in the region of the vestibule, and anterior the vestibule, and anterior portion of the septumportion of the septum
Venous DrainageVenous Drainage:: VeinsVeins begin as a rich plexus in the begin as a rich plexus in the
submucosa, accompany the corresponding submucosa, accompany the corresponding arteries, and drain into the arteries, and drain into the facialfacial, , ophthalmicophthalmic, , and and sphenopalatine veins. sphenopalatine veins.
LymphaticLymphatic DrainageDrainage:: The lymphatics from the:The lymphatics from the:
Vestibule Vestibule drain into the drain into the submandibularsubmandibular lymph nodeslymph nodes
Rest of the cavity Rest of the cavity drains into the drains into the upper upper deep cervicaldeep cervical lymph nodes lymph nodes
Functions of Nose & Nasal CavitiesFunctions of Nose & Nasal Cavities Air conditioningAir conditioning: warming, cleaning and humidifying the : warming, cleaning and humidifying the
inhaled airinhaled air Add resonance to the voiceAdd resonance to the voice Vocal sounds are also produced in the nasal cavity thus Vocal sounds are also produced in the nasal cavity thus
aiding in vocalisationaiding in vocalisation Involved in the Involved in the special sense of smellspecial sense of smell Central role of the nose in Central role of the nose in facial appearancefacial appearance
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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 cavitymucosa of the nasal cavity
Drain into the nasal cavity Drain into the nasal cavity through relatively small through relatively small aperturesapertures
DrainageDrainage of the sinuses mainly depends on the movement of the ciliamovement of the cilia, which , which propel the mucus toward their openings in the nasal cavity
The development of sinuses The development of sinuses begins in 3-4 month, but begins in 3-4 month, but only only maxillarymaxillary & & ethmoid ethmoid sinuses are present in sinuses are present in rudimentary form at birth. rudimentary form at birth. The The frontalfrontal & & sphenoidalsphenoidal sinuses are not clinically sinuses are not clinically perceptible at birth and can perceptible at birth and can rarely be demonstrated on rarely be demonstrated on plain x-ray before two years plain x-ray before two years of age.of age.
Continue to grow postnatallyContinue to grow postnatally Enlarge appreciably after Enlarge appreciably after 88thth
year year & become fully formed & become fully formed at adolescenceat adolescence
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From a 3 months old fetus, showing ethmoid & maxillary sinuses
FunctionsFunctions
Lighten the skullLighten the skull Act as resonant chambers for speechAct as resonant chambers for speech The respiratory mucosal lining helps in The respiratory mucosal lining helps in
warming, cleaning and moistening the warming, cleaning and moistening the incoming airincoming air
Maxillary SinusesMaxillary Sinuses• Located within the Located within the body of the body of the
maxillamaxilla• PyramidalPyramidal in shape with the in shape with the
base forming the lateral wall base forming the lateral wall of nose & the apex lies in the of nose & the apex lies in the zygomatic process of the zygomatic process of the maxillamaxilla
• RoofRoof: formed by the : formed by the floor of floor of the orbitthe orbit
• FloorFloor: formed by the : formed by the alveolar alveolar borderborder. Roots of 1. Roots of 1stst and 2 and 2ndnd premolars and the 3premolars and the 3rdrd molar molar (sometimes canines) project (sometimes canines) project into the sinusinto the sinus
• Opens into the Opens into the middle meatus middle meatus through the hiatus semilunaristhrough the hiatus semilunaris
• Supplied by Supplied by superior alveolar superior alveolar & & infraorbital nervesinfraorbital nerves
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Frontal SinusesFrontal Sinuses TwoTwo in number in number Located within the Located within the
frontal bonefrontal bone, separated , separated from each other by a from each other by a bony septumbony septum
TriangularTriangular in shape, in shape, extending backward extending backward into the into the roof of the orbitroof of the orbit
Opens into the Opens into the middle middle meatusmeatus through the through the infundibuluminfundibulum
Supplied by the Supplied by the supraorbital nervesupraorbital nerve
Ethmoidal SinusesEthmoidal Sinuses LocatedLocated within the within the
ethmoid boneethmoid bone, , between the nose between the nose and the orbitand the orbit
Divided into Divided into three three groupsgroups: : anterioranterior, , middlemiddle & & posteriorposterior
Anterior group Anterior group opens opens into the into the infundibuluminfundibulum, , middlemiddle opens on the opens on the bullabulla, and , and posteriorposterior into the into the superior superior meatusmeatus
Supplied by the Supplied by the anterioranterior and and posterior posterior ethmoidal nervesethmoidal nerves
Sphenoidal SinusesSphenoidal Sinuses
TwoTwo in number in number Located within the Located within the
body of sphenoidbody of sphenoid Open into the Open into the
sphenoethmoidal sphenoethmoidal recessrecess
Supplied by the Supplied by the posterior ethmoidal posterior ethmoidal nervenerve
Clinical NotesClinical Notes Epistaxis:Epistaxis: Little’s area, Little’s area,
common site of bleeding common site of bleeding from nose from nose
Inflammation of the nasal Inflammation of the nasal mucosamucosa, , RhinitisRhinitis, results in , results in nasal congestion and nasal congestion and excessive production of excessive production of mucus leading to mucus leading to ‘postnasal drip’‘postnasal drip’
Infections of the nasal Infections of the nasal cavity cavity can extend to the:can extend to the: Paranasal sinusesParanasal sinuses Nasolacrimal duct & Nasolacrimal duct &
lacrimal saclacrimal sac
Inflammation of mucosa of Inflammation of mucosa of the sinusesthe sinuses, , SinusitisSinusitis, , causes excessive causes excessive production of mucus leading production of mucus leading to obstruction of the to obstruction of the drainage of sinuses. This drainage of sinuses. This results in headache and results in headache and change in the voicechange in the voice
Infection of frontal & Infection of frontal & anterior ethmoidal sinusanterior ethmoidal sinus can easily spread to can easily spread to maxillary sinus because of maxillary sinus because of the location of their the location of their openingsopenings
Infection of upper teethInfection of upper teeth can can lead to inflammation of the lead to inflammation of the maxillary sinusmaxillary sinus
Extraction of an infected Extraction of an infected upper tooth upper tooth may result in a may result in a fistulafistula
The The maxillary sinus maxillary sinus is most is most commonly the site of infection commonly the site of infection
The inflamed mucosa results in excessive production of mucus as well as narrowing of its opening in the nasal cavity
The position of the drain causes problems in that mucus can collect in the sinus below the drain. In this situation, the sinus will only drain if the patient lies on their opposite side.
Pressure from the trapped fluid/mucus causes sinus pain
Thank You & G
ood
Luck