Transcript PALATE - medscistudents

Anatomy of Swallowing
• Strucures
• Muscles
• Nerves
• Vascular supply
PALATE
HARD AND SOFT
• Forms the arched part of the mouth and floor of
nasal cavities.
• Separates the oral cavity from the nasal cavities
and the nasopharynx, part of the pharynx superior
to the soft palate.
• Superior (nasal) surface of the palate is covered
with respiratory mucosa and the inferior (oral)
surface is covered with oral mucosa densely
packed with glands.
• The palate consists of two regions: the hard and
soft palate posteriorly.
Hard Palate
• Palatine processes of the maxillae form the
anterior 2/3s of the hard palate. Could be 3/4s
• The horizontal plates of the palatine bones
form the posterior 1/3. Could be 1/4s
• In the oral cavity, the upper alveolar arch
borders the hard palate anteriorly and laterally.
• Posteriorly the hard palate is continuous with
the soft palate.
• A single nasal spine is formed at the midline
where the 2 horizontal plates join and projects
backwards from the margin of the hard palate.
The posterior margin of the horizontal plates
and the posterior nasal spine are associated
with the attachment of the soft palate.
• The mucosa of the hard palate in the oral
cavity possesses numerous transverse palatine
folds ( palatine rugae) and a median
longitudinal ridge (palatine raphe) which ends
anteriorly in a small oval elevation (incisive
papillae) The incisive papillae overlies the
incisive fossa formed between the horizontal
plates of the maxillae immediately behind the
incisor teeth.
GREATER PALATINE FORAMEN
• Formed mainly by the horizontal plate of the
palatine bone and completed laterally by the
adjacent part of the maxilla, opens onto the
posterolateral aspect of the horizontal plate.
• This foramen is the inferior opening of the
palatine canal, which continues superiorly into
the pterygopalatine fossa and transmits the
greater palatine nerves and vessels to the
palate.
• Greater palatine foramen medial to the 3rd molar
the greater palatine foramen pierces the lateral
border of the bony plate
• The greater palatine vessels and nerve emerge
from this foramen and run anteriorly on the plate
• The lesser palatine foramina posterior to the
greater palatine foramen pierce the pyramidal
process of the palatine bone
• These foramina transmit the lesser palatine nerves
and vessels to the soft palate and adjacent
structures.
Incisive Fossa
• Incisive Fossa is a depression in the midline of
the bony palate posterior to the central incisive
teeth into which the incisive canals open. The
nasopalatine nerves pass from the nose though
a variable number of incisive canals and
foramina that open into the incisive fossa.
incisive fossa
Greater palatine foramen
Lesser palatine foramen
Innervation Palate
• The sensory nerves of the palate are branches of
the maxillary nerve ,(CNV2), which branch from
the pterygopalatine ganglion.
• The greater palatine nerve supplies the gingivae,
mucous membrane and glands of most of the hard
palate.
• The nasopalatine nerve supplies the mucous
membrane of the anterior part of the hard palate.
• The lesser palatine nerve supply the soft palate.
Swallowing
• When a person swallows the soft palate
initially is tensed to allow the tongue to press
against it, squeezing the bolus of food to the
back of the mouth. The soft palate is then
elevated posteriorly and superiorly against the
wall of the pharynx, thereby preventing the
passage of food into the nasal cavity.
SOFT PALATE
The soft palate
• The structure composed of mucous membranes, muscular
fibers, and mucous glands, suspended from the posterior
border of the hard palate forming the roof of the mouth.
• When the soft palate rises, as in swallowing, it separates the
nasal cavity and nasopharynx from the posterior part of the
oral cavity and oral portion of the pharynx.
• In sucking the soft palate and posterior superior surface of
the tongue occlude the oral cavity from the oropharynx,
creating a posterior seal. Thus the soft palate prevents the
escape of fluid and food up through the nose and with the
tongue allows fluid and food to collect in the mouth until
swallowed.
HARD PALATE
SOFT PALATE
UVULA
• While swallowing, the soft palate is pushed
backwards. This prevents food and drink from
entering the nasal cavity; if the soft palate
cannot touch the back of the throat while
swallowing, food and drink can enter the nasal
cavity.
• Moveable posterior third of the palate and is suspended
from the posterior border of the hard palate.
• The soft palate has no bony skeleton however its
anterior aponeurotic part is strengthened by the palatine
aponeurosis which attaches to the posterior edge of the
hard palate.
• The aponeurosis is thick anteriorly and thin posteriorly
where it blends with a posterior muscular part.
• Posterioinferiorly the soft palate has a curved free
margin from which hangs the uvula.
• Laterally the soft palate is continuous with the
wall of the pharynx and joined to the tongue
by the palatoglossal and palapharyngeal arches
respectively.
Fauces
• The Fauces (the throat) is the space between the cavity of the mouth
and the pharynx.
• The fauces is bounded superiorly by the soft palate and inferiorly by
the root of the tongue and laterally by the pillars of the fauces, the
palatoglossal and palatopharyngeal arches.
• The isthmus of the fauces is the short constricted space that
establishes the connection between the oral cavity proper and the
oropharynx. The isthmus is bounded anteriorly by the palatoglossal
folds and posteriorly by the palatopharyngeal arches.
• The palatine tonsils often referred to as the “the tonsils” are masses
of lymphoid tissue, one on each side of the oropharynx.
• Each tonsil is in a tonsillar fossa (sinus) bounded by the
palatoglossal and palatopharyngeal arches and the tongue.
1vestibule
2hard palate
3soft palate
4uvula
5palatoglossal arch
6palatine tonsil
7palatopharyngeal arch
8posterior wall of
oropharynx
9pterygoid hamulus
Muscles soft palate
Tensor veli
Palatini
Levator veli
Palatini
Palatoglossus
Paltopharyngeus
Musculus
Uvulae
TENSOR VELI PALATINI
• Composed of two parts
• Vertical muscle muscular part
• Horizontal fibrous part which forms the
palatine aponeurosis
• Vertical part of the tensor veli palatini is thin
and triangular in shape with its base attached
to the skull and its apex pointed inferiorly.
• The base is attached along an oblique line that
begins medially at the scaphoid fossa near the
root of the pterygoid process of the sphenoid
bone and continues laterally along the
membranous part of the pharynotympanic tube
to the spine of the sphenoid bone.
Tensor Veli Palatini
• The tensor veli palatini descends vertically along the
lateral surface of the medial plate of the pterygoid
process and pharyngeal wall to the pterygoid hamulus
where the fibers converge to form a small tendon.
• The tendon loops 90 degrees medially around the
pterygoid hamulus, penetrating the origin of the
buccinator muscle as it does and expands like a fan to
form the fibrous horizontal part of the muscle. This
fibrous part is continuous across the midline with the
partner on the other side to form the palatine
aponeurosis
Palatine Aponeurosis
• Attached anteriorly to the margin of the hard
palate but is unattached posteriorly where it
ends in a free margin. This expansive
aponeurosis is the major structural element of
the soft palate to which the other muscles of
palate attach.
Tensor Veli Palatini
• Actions:
• Tenses (makes firm) the soft palate
• Opens the mouth of the pharyngotympanic
tube (auditory tube) during yawning and
swallowing.
The tensor veli palatini it is found lateral to the levator veli
palatini muscle.
It arises by a flat lamella from the scaphoid fossa at the base of
the medial pterygoid plate, from the spina angularis of the
sphenoid and from the lateral wall of the cartilage of the auditory
tube
Descending vertically between the medial pterygoid plate and the
medial pterygoid muscle, it ends in a tendon which winds around
the pterygoid hamulus, being retained in this situation by some of
the fibers of origin of the medial pterygoid muscle
Between the tendon and the hamulus is a small bursa.
The tendon then passes medialward and is inserted into the
palatine aponeurosis and into the surface behind the transverse
ridge on the horizontal part of the palatine bone.
Levator veli palatini
• Origin base of skull and descends to the upper
surface of the palatine aponeurosis.
• On the skull it originates from a roughened area
on the petrous part of the temporal bone
immediately anterior to the opening of the Carotid
canal.
• Levator veli palatini passes anterioinferiorly
through fascia of the pharynotympanic tube and
inserts onto the palatine aponeurosis. Its fibers
interlaces at the midline with those of the levator
veli palatini on the other side.
• The levator veli palatinin does not pass around
the pterygoid hamulus but courses directly
from the base of the skull to the upper surface
of the palatine aponeurosis.
• Therefore they elevate the palate above the
neutral position and close the pharyngeal
isthmus between the nasopharynx and
oropharynx.
Palatopharyngeus
• Originates from the superior surface of the
palatine aponeurosis and passes posterolaterally
over its margin to descend and become one of the
longitudinal muscles of the pharyngeal wall.
• Attached to the palatine aponeurosis by 2 flat
lamellae separated by the levator veli palatini.
• The more anterior and lateral of these 2 lamellae
is attached to the posterior margin of the hard
palate as well as to the palatine aponeurosis.
• The 2 palatopharyngeus muscles one on each
side underlie the palatopharyngeal arches on
the oropharyngeal wall. The palatopharyngeal
arches lie posterior and medial to the
palatoglossal arches
•
• Action palatopharyngeus muscle
• Depress the palate and move the
palatopharyngeal arches toward the midline
like curtains both these actions help close the
oropharyngeal isthmus.
• Elevate the pharynx during swallowing.
PALATOGLOSSUS
• This muscle is attached to the inferior (oral
surface) of the palatine aponeurosis and passes
inferiorly and anteriorly into the lateral surface of
the tongue.
• The palatoglossus muscle underlies a fold of
mucosa that arches from the soft palate to the
tongue. These palatoglossal arches, one on each
side are lateral and anterior to the
palatopharyngeal arches and define the lateral
margins of the oropharygeal isthmus.
• The palatine tonsil is between the palatoglossal
and palatopharyngeal folds on the lateral
oropharyngeal wall.
• The palatoglossus muscles depresses the
palate, move the palatoglossal arches toward
the midline like curtains and elevate the back
of the tongue. These actions help close the
oropharyngeal isthmus.
• Innervation vagus nerve.
Musculus Uvulae
• Originates from the posterior nasal spine on the
posterior margin of the hard palate and passes
directly over the dorsal aspect of the palatine
aponeurosis to insert into connective tissue
underlying the mucosa of the uvula.
• It passes between the 2 lamellae of the
palatopharyngeus superior to the attachment of
the levator veli palatini. Along the midline the
muscle blends with its partner on the other side.
• ACTION: Elevates and retracts the uvula.
This action thickens the central part of the soft
palate and helps the levator veli palatini
muscles close the pharyngeal isthmus between
the nasopharynx and oropharynx.
• Innervated by the vagus (CNX) through the
pharyngeal branch to the pharyngeal plexus.
• The uvula is a small, mucosa-covered set of
muscles, musculus uvulae, hanging down
from the soft palate, near the back of the
throat. The word is derived from the
diminutive of uva, the Latin word for
"grape", due to the uvula's grape-like shape
VESSELS
• Arteries of the palate include the greater
palatine branch from the maxillary artery, the
ascending palatine branch of the facial artery
and the palatine branch of the ascending
pharyngeal artery. The maxillary, facial and
ascending pharyngeal arteries are all branches
that arise in the neck from the external carotid
artery.
Ascending palatine artery and palatine
branch
• The ascending palatine artery of the facial
artery ascends along the external surface of the
pharynx. The palatine branch loops medially
over the top of the superior constrictor muscle
of the pharynx to penetrate pharyngeal fascia
with the levator veli palatini muscle and follow
levator veli palatini to the soft palate.
• The palatine branch of the ascending
pharyngeal artery follows the same course as
the palatine branch of the ascending palatine
artery from the facial artery and may replace
the vessel.
GREATER PALATINE ARTERY
• Originates from the maxillary artery in the
pterygopalatine fossa
• Descends into the palatine canal where it gives
origin to a lesser palatine branch and then
continues through the greater palatine foramen
onto the inferior surface of the hard palate. The
greater palatine artery passes forward on the hard
palate and then leaves the palate superiorly
through the incisive to enter the medial wall of
the nasal cavity where it terminates.
• The greater palatine artery is the major artery
of the hard palate
• The lesser palatine artery passes through the
lesser palatine foramen just posterior to the
greater palatine foramen contributes to the
vascularization of the soft palate.
Innervation
• Palate receives its innervation from the
nasopalatine, greater and lesser palatine
nerves.
• Sensory fibers is carried in all of these nerves
originate in the pterygopalatine fossa from the
( CN V2 maxillary nerve)
• Greater and lesser palatine nerves descend
through the pterygopalatine fossa and palatine
canal to reach the palate:
• Greater palatine nerve travels through the
greater palatine foramen and turns anteriorly to
supply the hard palate, gingiva as far as the
first premolar.
• Lesser palatine nerve passes posteromedially to supply
the soft palate
• Nasopalatine nerve also originates in the
pterygoapalatine fossa but passes medially into the
nasal cavity. It continues medially over the roof of the
nasal cavity to reach the medial wall, then anteriorly
and obliquely down the wall to reach the incisive canal
in the anterior floor and descends through the incisive
canal and fossa to reach the inferior surface of the hard
palate. Supplies gingiva and mucosa adjacent to the
incisors and canine.