Download 19. oral cavity+pharynx2010-10-01 03:411.2 MB

The Mouth
The mouth cavity is divided into
vestibule & mouth cavity proper.
 Vestibule of mouth lies between lips
+ cheeks (buccinator) externally, /and
gums + teeth internally.
H. S. of mouth & oral pharynx.
The mouth cavity proper :
Boundaries :
1-In front and at the sides : gums & teeth
2- Roof : hard palate in front & soft
palate behind.
3- Floor : anterior 2/3 of tongue &
sublingual region.
4-Posteriorly : mouth communicates with
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oropharynx by oropharyngeal isthmus.
The parotid duct opens at the
vestibule of mouth opposite
upper 2nd molar tooth.
Sublingual Region : lies in the
floor of mouth below tongue,
contains :
1-The frenulum of the tongue is a
fold of mucous membrane in the
midline connects undersurface of
tongue to floor of mouth.
2-Duct of submandibular gland
opens on each side of frenulum.
3-Sublingual gland is covered by
m.m called sublingual fold, which
extends laterally on both sides from
lower part of frenulum, and
sublingual ducts open by many2
aperatures on its summit.
Sensory nerve supply of mucous
membrane of mouth :
• Roof (palate) : greater palatine &
Nasopalatine nerves from Maxillary N.
• Floor (anterior 2/3 of tongue) : lingual N. of
mandibular N. (general sensation), +
chorda tympani N. of facial N. (taste
sensation).
• Cheek : buccal nerve, a branch of
mandibular N.
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The Tongue
It is a mass of striated
muscle covered with mucous
membrane.
Its anterior 2/3 lies in
mouth (oral part), while
posterior 1/3 lies in pharynx
(pharyngeal part).
It is divided into right &
left halves by a median
fibrous septum.
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The Tongue
Mucous membrane of the Upper
surface of tongue (dorum of
tongue)
--Oral & pharyngeal parts are
separated by a V-shaped groove
called sulcus terminalis, the apex of
sulcus is marked by a pit called
foramen coecum ( is an embryologic
remnant of upper end of
thyroglossal duct).
--The mucous membrane of oral
part (anterior 2/3) contains vallate
papillae.
--The mucous membrane of
pharyngeal part (post.1/3) devoid of
papillae, but it has a nodular irrigular5
The Tongue
Mucous membrane of inferior
surface of the tongue :
-- The mucosa is smooth.
-- In the midline, it is connected
to the floor of mouth by a fold of
m.m. called frenulum of tongue.
-- On lateral side of frenulum,
deep lingual vein lies in
submucosa, can be seen through
the mucosa. But Lingual N. &
lingual artery run at deeper plane
from mucosa.
-- Lateral to vein, a serrated fold
of mucosa is seen ‘plica
fimbriata’
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Innervation of the Tongue :
(vagus)
Motor Nerves :
-- All intrinsic & extrinsic muscles are
supplied by hypoglossal N. EXCEPT
palatoglossus is supplied by
pharyngeal plexus via vagus N.
Sensory Nerves :
1-Anterior 2/3 : general sensations : by
lingual N….taste sensations (excluding
vallate paoillae) : by chorda tympani.
2-Posterior 1/3, including vallate
papillae : general & taste sensations by
glossopharyngeal N.
3-Root of tongue ( most posterior part)
: internal laryngeal branches of vagus.
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Blood Supply of Tongue
• Lingual artery : branch of external
carotid artery, it supply most of tongue
(the main arterial supply)
• Tonsillar (branch of facial) +
Ascending pharyngeal artery
(branch of ext.carotid artery) : they supply
posterior part of tongue.
• Veins of tongue form lingual vein ,which
drains into internal jugular vein.
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Lymph Drainage of Tongue
Tip of tongue : drain into
submental L.Ns.
The remainder of anterior
2/3 of tongue : drains into
submandibular + inferior deep
cervical L.Ns.
Posterior 1/3 of tongue :
drains into superior deep cervical
L.Ns.
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Muscles of Tongue
• Intrinsic muscles :
-They are not attached to bone.
-They consist of longitudinal,
transverse & vertical fibers (inside the
tongue).
-Origin : median septum & submucosa.
-Insertion : mucous membrane.
-Nerve supply : hypoglossal N.
-function : Alter the shape of tongue.
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Extrinsic Muscles of Tongue
Extrinsic muscles :
-They connect tongue to
styloid process & soft palate
above, /and to mandible &
hyoid bone below.
-They are :
1-Genioglossus.
2-Hyoglossus.
3-Styloglossus.
4-palatoglossus.
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Extrinsic Muscles of Tongue
Genioglossus :
-Origin : superior mental
tubercle of mandible.
-Insertion : it is fan-shaped,
blends with other muscles
of tongue (into tongue, &
body of hyoid bone).
-Action :
-The 2 muscles : protrude
tip of tongue through
mouth.
-One muscle : protrudes the
tongue to opposite side.
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Extrinsic Muscles of Tongue
Hyoglossus :
-Origin : body + greater cornu of
Hyoid bone.
-Insertion : it is quadrilateral, runs
upward deep to mylohyoid muscle to
insert at side of post.part of tongue.
-Action :
Depress tongue and increase mouth
cavity during swallowing.
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Structures Superficial to
Hyoglossus
Superficial relations :
1-Mylohyoid + Styloglossus.
2-Lingual N.
3-Hypoglossal N.
4-Submandibular ganglion.
5-Deep part of submandibular gland.
 ligual artery (deep to hyoglossus)
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Extrinsic Muscles of Tongue
Styloglossus :
-Origin : styloid process.
-Insertion :blends with other muscles
of tongue.(whole length of side of
tongue).
Action :
Pulls tongue upward and backward
(retraction + elevation) during
swallowing.
It passes between superior &
middle constrictors of pharynx to
reach tongue.
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Extrinsic Muscles of Tongue
Palatoglossus :
-Origin : from undersurface of
palatine aponeurosis (soft palate).
-Insertion : into the side of post.1/3
of tongue.
-Action : pulls root of tongue
upward & backward, (retraction +
elevation), so narrows
oropharyngeal isthmus and
prevents regurgitation of food.
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Movements of Tongue
Protrusion : genioglossus on
both sides acting together.
Retraction : styloglossus +
hyoglossus Ms. on both sides.
Depression : hyoglossus +
genioglossus Ms. on both sides.
Retraction & elevation of
posterior 1/3 of tongue :
Styloglossus + Palatoglossus,
on both sides.
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The Palate
It forms the roof of mouth.
It is divided into : hard palate
anterior & soft palate posterior.
Hard palate :
-It forms anterior 2/3 of palate.
-it is formed by palatine processes
of maxillae + horizontal plates of
palatine bones.
-It is bounded laterally by alveolar
arches and continuous behind with
soft palate.
-It forms floor of nasal cavities.
–It is covered with muco18
periosteum.
Soft Palate
It forms the posterior 1/3 of
palate.
It is a mobile fold attached
anteriorly to the hard palate.
Soft palate
Its posterior free end forms
a conical projection in the
midline called the Uvula.
It lies between the naso pharynx & oropharynx.
Laterally , it is attached to
side wall of pharynx.
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Structures of Soft Palate
Mucous Membrane : covers
its upper & lower surfaces.
Palatine aponeurosis
Soft palate is seen from behind
Palatine aponeurosis :
it is a fibrous sheet in the
middle, attached to posterior
border of hard palate, it is the
expanded tendon of Tensor
veli palatini on both sides.
Muscles of Soft Palate :
1-Tensor vili palatini.
2-Levator vili palatini.
3-Palatoglossus.
4-Palatopharyngeus.
5-Musculus uvulae.
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Muscles of Soft Palate
Tensor veli palatini :
-Origin : spine of sphenoid +
auditory tube.
-Insertion :with muscle of other
side forms palatine aponeurosis
which is inserted into palatine
crest (posterior border of hard
palate).
–N.supply : N. to medial
perygoid from mandibular N.
-Action : tense soft palate.
Soft palate is seen from behind
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Muscles of Soft Palate
Levator veli palatini :
-Origin : Petrous part of temporal bone +
auditory tube.
-Insertion : palatine aponeurosis.
- N.supply : pharyngeal plexus.
-Action : elevates soft palate, shutting off
nasopharynx fron oropharynx in swallowing.
Soft palate is seen from behind.
Palatopharyngeus :
-Origin : palatine aponeurosis.
-Insertion : posterior border of thyroid
cartilage+ wall of pharynx. It lies in a fold of
m.m of lateral wall of pharynx, called
palatopharyngeal arch.
-N.supply : pharyngeal plexus.
-Action : The 2 muscles elevate wall of
pharynx + closing of ‘‘pharyngeal isthmus’’
during swallowing (communicating channel
between nasal & oral parts of pharynx). 22
Muscles of Soft Palate
Palatoglossus :
-Origin : palatine aponeurosis.
-Insertion : side of post.1/3 of tongue,
it lies in a fold of m.m. of lateral wall
of oro-pharynx, called palatoglossal
arch, which lies in front of palatine
tonsile.
-N.supply : pharyngeal plexus.
-Action : the 2 muscles pull root of
tongue upward & backward, causing
narrowing of ‘oropharyngeal isthmus’
and prevent regurgitation
Musculus
uvulae : of food.
-Origin : posterior border of hard palate
(post. Nasal spine).
-Insertion : m.m.of uvulae.
-N.supply : pharyngeal plexus.
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-Action : elevates uvulae.
palatoglossal & palatopharyngeal
arches : are folds of mucous
membranes covering the muscles of
sot palte, palatoglossus &/
palatopharyngeus in the oropharynx.
Oropharyngeal isthmus :
it is a sphincter between mouth &
oral part of pharynx, and it is
marked by the interval between 2
palatoglossal arches.
Pharyngeal isthmus :
it is the opening between the free
end of soft palate & posterior wall of
pharynx
( communication between the nasal
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and / oral parts of pharynx)
Innervations of Soft Palate
• Motor : all palatine muscles are supplied by
pharyngeal plexus EXCEPT tensor veli
palatini.
(by N.to medial
pterygoid from mandibular N.).
• Sensory :
1- Greater & Lesser palatine Ns. of
maxillary,
2Nasopalatine N. of maxillary N.
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Blood Supply & Lymph Drainage of soft
Palate :
• Greater palatine from maxillary artery.
• Ascending palatine from facial artery.
• Ascending pharyngeal artery from
external carotid artery.
• Veins of palate : end in pterygoid &
tonsillar venous plexus.
• Lymph vessels of palate : end in deep
cervical L.Ns.
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