Nose(Anatomy)
NOSE
INTRODUCTION
The
part of the respiratory tract superior to the hard palate and contains the
peripheral organ of smell.
FUNCTIONS
Olfaction
(smelling)
Respiration
Filtration
of dust
Humidification
of inspired air
Reception
and elimination of secretions from the paranasal sinuses and nasolacrimal
ducts.
Nose
consists of the external nose and nasal cavity.
External
nose
the
visible portion that projects from the face
Covered
with skin
It
is a pyramidal projection
Presents
: tip or apex, root, dorsum,
Inferior
surface presents a pair of apertures known as nostrils or nares.
SKELETON OF EXTERNAL NOSE
Bony
part:
Nasal
bones
Frontal
process of maxilla
Nasal
part of frontal bone and its nasal spine
Cartilagenous
part
Two
lateral cartilages
Two
alar cartilages
One
septal catilage
NASAL CAVITIES
Refers
either to entire cavity or to right and left half
Entered
anteriorly through nostrils
Opens
posteriorly into nasopharynx through choanae
Nasal cavity can be divided into three regions
Vestibule
Respiratory
olfactory
Vestibule
Slightly
dilated area above nostrils
Lined
by skin
Provided
with coarse hair and sebaceous gland
Respiratory
region
Serves
as main air passage
Paranasal
sinuses open in this region
Lined
by pseudostratified ciiated columnar epithelium, provided with goblet cells and
mucus and serous glands
Boundaries
Each
half of the nasal cavity presents roof, floor, medial and lateral walls.
Roof
It
is narrow from side to side and slopes downwards, both in front and behind.
Consists
of three parts-
Anterior
: frontonasal
Intermediate
: ethmoidal
Posterior
: sphenoidal
Floor
It
is smooth, concave, and much wider than the roof.
Formed
by palatine process of maxilla and horizontal plate of palatine bone.
Nasal
septum
It
is formed partly by bones and partly by cartilages.
Bony
part
Perpendicular
plate of ethmoid
Vomer
Nasal
spine of frontal bone
Sphenoid
Nasal
crest of Palatine and maxillary bone
Medial
wall or nasal septum
Cartilagenous part
Septal
cartilage
Sepal
process of lower nasal cartilage
The
lower margin of the septum is called the columella.
VENOUS
DRAINAGE
Antero-superior
part : into opthalmic vein
Postero-inferior
part : into pterigoid venous plexus
Mobile
part : internal jugular vein through facial vein.
Upper
part of septum: accompany the olfactory nerves and drain into inferior cerebral
vein.
Lateral
wall
It
is formed largely by
the
maxilla anteroinferiorly
the
perpendicular plate of the palatine bone posteriorly
superiorly
by the labyrinth of the ethmoid bone
contains
three projections of variable size
Inferior
nasal conchae
Middle
nasal conchae
Superior
nasal conchae
The
nasal conchae curve generally inferomedially, each roofing a groove, or meatus
Superior
Concha
a
medial process of the ethmoidal labyrinth
presents
as a small curved lamina
Lies
posterosuperior to the middle concha.
The
superior meatus : short oblique passage extending about halfway along the upper
border of the middle concha.
The
posterior ethmoidal sinuses open, via a variable number of apertures, into its
anterior part.
Supreme
meatus
Area
between superior concha and nasal roof
Above
and behind superior concha lies a depression, the sphenoethmoidal recess
Receives
the opening from spenoidal sinus
Middle
Concha
a
medial process of the ethmoidal labyrinth
extends
back to articulate with the perpendicular plate of the palatine bone
region
beneath middle concha is the middle meatus
The
main features are
a
rounded elevation, the bulla ethmoidalis
a
curved cleft, the hiatus semilunaris
MIDDLE
CONCHA
Bulla
Ethmoidalis : bony bulging containing middle ethmoidal air sinuses
Receives
the openings from middle ethmoidal air sinuses
Hiatus
Semilunaris : crescentic space below bulla ethmoidalis
Its
floor receives the opening of maxillary sinus
Anteriorly
presence of ethmoidal infundibulum ; it receives anterior ethmoidal sinuses and
frontal sinus
Frontal
sinus may open through fronto-nasal duct
Inferior
Nasal Concha
A
thin, curved, independent bone
articulates
with the nasal surface of the maxilla and the perpendicular plate of the
palatine bone
free
lower border is gently curved and the subjacent inferior meatus reaches the
nasal floor.
The
inferior meatus is the largest meatus
Continuous
anteriorly with the vestibule of nose
Receives
opening of the nasolacrimal duct in its anterior part
Arterial
supply
Anterio-superior
quadrant : anterior ethmoidal artery from opthalmic artery
Anterio-inferior
quadrant: alar branches of facial artery and terminal branches of
greaterpalatine artery
Posterio-superior
quadrant: sphenoplatine branch of maxillary artery
Postero-inferior
quadrant: branches of Greater palatine artery
Venous
drainage
Veins
form a plexus which drain into
Facial
vein in front
Retro-pharyngeal
vein and pterygoid venous plexus behind
Inferior
cerebral vein above
Applied
anatomy
Lesions
of olfactory nerves due to fracture of cribriform plate may result in loss of
sense of smell (anosmia)
Deviation
of nasal septum
Epistaxis:
most
episodes occur on the anteroinferior portion of the septum and involve the
septal branches of the sphenopalatine and facial vessels.
Little’s
area or Kiesselbach area
FUNCTIONS
Olfaction
(smelling)
Respiration
Filtration
of dust
Humidification
of inspired air
Reception
and elimination of secretions from the paranasal sinuses
and nasolacrimal ducts.
Nose consists of the external nose and nasal
cavity.
External nose
the visible portion that projects from the face
Covered with skin
It is a pyramidal projection
Presents : tip or apex, root, dorsum,
Inferior
surface presents a pair of apertures known as nostrils or nares.
SKELETON OF EXTERNAL NOSE
Bony part:
Nasal
bones
Frontal
process of maxilla
Nasal
part of frontal bone and its nasal spine
Cartilagenous part
Two
lateral cartilages
Two alar cartilages
One
septal catilage
NASAL CAVITIES
Refers either to entire cavity or to right and left half
Entered anteriorly through nostrils
Opens posteriorly into nasopharynx through choanae
Nasal cavity can be divided into three regions
Vestibule
Respiratory
olfactory
Vestibule
Slightly dilated area above nostrils
Lined by skin
Provided with coarse hair and sebaceous gland
Respiratory region
Serves as main air passage
Paranasal sinuses open in this region
Lined by pseudostratified ciiated columnar
epithelium, provided with goblet cells and mucus and serous glands
Boundaries
Each half of the nasal cavity presents roof, floor,
medial and lateral walls.
Roof
It is narrow from side to side and slopes downwards, both
in front and behind.
Consists of three parts-
Anterior : frontonasal
Intermediate : ethmoidal
Posterior : sphenoidal
Floor
It is smooth, concave, and much wider than
the roof.
Formed by palatine process of maxilla and horizontal
plate of palatine bone.
Nasal septum
It is formed partly by bones and partly by cartilages.
Bony part
Perpendicular
plate of ethmoid
Vomer
Nasal
spine of frontal bone
Sphenoid
Nasal
crest of Palatine and maxillary bone
Medial wall or nasal septum
Cartilagenous part
Septal
cartilage
Sepal
process of lower nasal cartilage
The lower margin of the septum is called
the columella.
VENOUS DRAINAGE
Antero-superior part : into opthalmic vein
Postero-inferior part : into pterigoid venous
plexus
Mobile part : internal jugular vein through facial vein.
Upper part of septum: accompany the olfactory nerves and
drain into inferior cerebral vein.
Lateral wall
It is formed largely by
the
maxilla anteroinferiorly
the
perpendicular plate of the palatine bone posteriorly
superiorly
by the labyrinth of the ethmoid bone
contains three projections of variable size
Inferior
nasal conchae
Middle
nasal conchae
Superior
nasal conchae
The nasal conchae curve
generally inferomedially, each roofing a groove, or meatus
Superior Concha
a medial process of the ethmoidal labyrinth
presents as a small curved lamina
Lies posterosuperior to the middle concha.
The superior meatus : short oblique passage extending
about halfway along the upper border of the middle concha.
The posterior ethmoidal sinuses open, via a
variable number of apertures, into its anterior part.
Supreme meatus
Area between superior concha and nasal roof
Above and behind superior concha lies a depression,
the sphenoethmoidal recess
Receives the opening from spenoidal sinus
Middle Concha
a medial process of the ethmoidal labyrinth
extends back to articulate with the perpendicular plate
of the palatine bone
region beneath middle concha is the middle meatus
The main features are
a
rounded elevation, the bulla ethmoidalis
a
curved cleft, the hiatus semilunaris
MIDDLE CONCHA
Bulla Ethmoidalis : bony bulging containing middle
ethmoidal air sinuses
Receives
the openings from middle ethmoidal air sinuses
Hiatus Semilunaris : crescentic space
below bulla ethmoidalis
Its
floor receives the opening of maxillary sinus
Anteriorly
presence of ethmoidal infundibulum ; it receives anterior ethmoidal
sinuses and frontal sinus
Frontal
sinus may open through fronto-nasal duct
Inferior Nasal Concha
A thin, curved, independent bone
articulates with the nasal surface of the maxilla
and the perpendicular plate of the palatine bone
free lower border is gently curved and the subjacent
inferior meatus reaches the nasal floor.
The inferior meatus is the largest meatus
Continuous anteriorly with the vestibule of nose
Receives opening of the nasolacrimal duct in
its anterior part
Arterial supply
Anterio-superior quadrant : anterior ethmoidal
artery from opthalmic artery
Anterio-inferior quadrant: alar branches of facial
artery and terminal branches of greaterpalatine artery
Posterio-superior quadrant: sphenoplatine branch
of maxillary artery
Postero-inferior quadrant: branches of Greater
palatine artery
Venous drainage
Veins form a plexus which drain into
Facial
vein in front
Retro-pharyngeal
vein and pterygoid venous plexus behind
Inferior
cerebral vein above
Applied anatomy
Lesions of olfactory nerves due to fracture of cribriform
plate may result in loss of sense of smell (anosmia)
Deviation of nasal septum
Epistaxis:
most
episodes occur on the anteroinferior portion of the septum and
involve the septal branches of the sphenopalatine and facial vessels.
Little’s
area or Kiesselbach area
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