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Head and NeckOral cavity
Professor Dr. Mohamed El Fiky Professor of anatomy and embryology
A. ORALVESTIBULEBoundaries:1. Anteriorly by lips2. Laterally by cheeks3. Posteriorly and medially by teeth
and gumsB. ORAL CAVITY PROPERBoundaries:1. Anteriorly laterally by teeth
and gums2. Superiorly by the palate3. Inferiorly by the tongue and
the floor of the mouth4. Posteriorly by opening into
the pharynx
1- Vestibule 2- mouth cavity proper .
The Mouth
Oral Vestibule
Oral Cavity Proper
The mouth cavity extends from the lips to the oropharyngealisthmus. It is composed of 2 main parts
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III. FLOOR OF THE MOUTH
Lingual frenulum (connects the tongue to the
floor of the mouth)
Papillae ( openings of submandibular duct)
Sublingual fold(passes lateraly and
backwards from the papilla and overlies the sublingual
gland)
Sublingual regionShows the following structures:Ø Frenulum of the tongueØ Sublingual papilla : lies on each side of the frenulum and the submandibular duct opens on itØ Sublingual fold : produced by the underlying sublingual salivarygland and the ducts of the gland open onits summit.
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TONGUE Ø It is composed of a striated muscular mass, covered by mucous membrane.Ø It is anterior 2/3 (oral part) lies in the floor of the mouth Ø It is posterior 1/3 (pharyngeal part) lies in the
oropharynxMuscles of the tongue:
Intrinsic muscles:Ø They consist of longitudinal, transverse & vertical fibers.Ø Nerve supply : Hypoglossal nerve.Ø Action: They alter the shape of the tongue.
Extrinsic muscles:
Hyoglossus , genioglossus , styloglossus and palatoglossus.
Nerve supply of the tongue: = Motor:Ø All the intrinsic & extrinsic muscles of the tongue aresupplied by the hypoglossal nerve EXCEPT thepalatoglossus which is supplied by the cranial root ofaccessory nerve through the pharyngeal plexus ( vago-accessory complex ).= Sensory:Ø Anterior 2/3:- Lingual nerve (general sensation)- Chorda tympani (taste sensation)Ø Posterior 1/3 : Glossopharyngeal nerve : (general & taste)Ø Root: Vagus nerve, through the internal laryngeal nerve.
Blood supply of the tongue:Ø Lingual arteryØ Tonsillar branch of facial artery
ØAscending pharyngeal artery Mohamed el fiky
PALATE
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Hard palate
Soft palate
PALATEØ It forms the roof of the mouth and floor of the nasalcavity.Ø It is divided into : hard (anterior 2/3) & soft (posterior 1/3)Hard palateØ It is the bony portion which is formed by the palatine process of the maxillae and the horizontal
plates of the palatine bone.
Soft palateØ A mobile fold attached to posterior border of hard palateØ It is formed of the palatine aponeurosis and muscles.
Muscles of the soft palate: = Tensor palati:Ø Origin : scaphoid fossa , spine of sphenoid and
lateral surface of the cartilaginous part of auditory tube.Ø Insertion : palatine aponeurosis and palatine crest.Ø Nerve supply : nerve to medial pterygoid
Ø Action : the 2 muscles tighten the soft palate.
Levator veli palatini:Ø origin : lower part of the auditory tube and lower
surface of the petrous bone.Ø Insertion : into the palatine aponeurosis.Ø Nerve supply : pharyngeal plexus.Action : elevates the soft palate.
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Palatoglossus:Origin: platine aponeurosis.Insertion : into the side of the tongue.Nerve supply : pharyngeal plexus .Action : pulls the root of the tongue upwards.= Palatopharyngeus:Origin : palatine aponeurosis.Insertion : posterior border of thyroid cartilage . Nerve suppy : pharyngeal plexus.Action : elevates the wall of the pharynx.= Musculus uvulae :Origin : posterior border of hard palate .Insertion: mucous membrane of uvula.Nerve supply : pharyngeal plexus.Action : elevates the uvula.Blood supply of the palateØ Greater palatine , lesser palatine and sphenopalatine arteries (from maxillary artery).Ø Ascending palatine artery (from facial artery)
Ø Ascending pharyngeal artery .Nerve supply of the palate:= SensoryØ Glossopharyngeal nerve.Ø Greater & lesser palatine nerves.Ø Middle palatine nerve.Ø Sphenopalatine nerve.= Motor:· All the muscles of the soft palate are supplied by the cranial part ofthe accessory nerve through the pharyngeal plexus EXCEPT the tensor palati which is supplied by the
mandibular nerve.Mohamed el fiky
Soft PalateMuscles of Soft Palate
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PHARYNX Ø It is a funnel shaped fibro-muscular tube of about 13 cm . lengthØ It extends form the base of the skull to the level of the 6th cervical vertebrae.Ø Its anterior wall is deficient and lies behind the cavities of the nose, mouth and larynxØ Accordingly it is divided into 3 parts: Nasopharynx , oropharynx & laryngeopharynx .
a)Base of skull (basioociput and basi
sphenoid) àsoft palate
b)Plane of hard palate àhyoid bone
c) Hyoid boneà lowerborder of cricoid
cartilage
Nasopharynx
Oropharynxx
Larygeopharynx
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WALLS OF THE PHARYNXConsists of the following from within outwards:1. Mucous coat lined by stratified squamous epithelium.2. Inner fibrous coat (pharyngo-basilar fascia).3. Muscular coat.4. Outer fibrous coat (buccopharyngeal fascia).
Muscles of the pharynx
Ø Outer circular layer:3 constrictors of the pharynx.
Ø Inner longitudinal layer:3 longitudinal muscles.
Sup.constrictor
mid.constrictor
inf.constrictor
Constrictors of the pharynx. 1- Sup.constrictor
2- mid.constrictor
3- inf.constrictorlongitudinal muscles.
1- Stylo-pharyngeus 2- Salpingo – pharyngeus
N.B. All muscles of pharynx take nerve supply from pharyngeal plexus except stylopharyngeusfrom glossopharyngeal nerve
3-Palato-pharyngeus:
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Pharyngeal Muscles
Stylopharyngeus
• O:medial aspect of styloidprocess
• Gap between middle and superior constrictor
• NS: glossopharyngeal
Palatopharyngeus
• O: upper surface of palatine aponeurosis as 2 fasiculi
• Moves along inner aspect of the constrictor
• NS: pharyngaelplexus
Salpingopharyngeus
• O: cartilage of the auditory tube near the pharyngeal opening of it.
LONGITUDINAL MUSCLES
All the 3 are inserted as a conjoint sheet at the post border of thyroid cartilage and lat aspect of epiglottis
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Pharyngeal Muscles
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Trachea Oesophagus
Digastric (posteriorbelly) cut
Middle constrictor
Stylohyoid ligament
Stylohyoid
Recurrent laryngeal nerve
Stylopharyngeus
Glossopharyngeal nerve
Thyropharyngeus
Cricopharyngeus
Pterygomandibularraphe
Buccinator
Pharyngotympanic tube
Superior constrictor
Tensor veli palatiniMandibular nerve
Levator veli palatini
Middle meningealartery
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Pharyngeal Muscles
Pharyngobasilar fascia
Styloid process
Attachment ofpharyngeal raphe to
pharyngeal tubercle (occipital bone)
Tensor veli palatini
Levator veli palatini
Stylohyoid (cut)
Stylopharyngeus
Styloglossus
Fibres of middleconstrictor fromstylohyoid ligament
Stylohyoid (cut)
Pharyngeal raphe
Greater cornuof hyoid bone
Inferior constrictor(cricopharyngeus)
Inferior constrictor(thyropharyngeus)
Middleconstrictor
Superiorconstrictor
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Lies in wall of nasopharynx and oropharynx Wide origin• Post border of med pterygoid plate &pterygoid
hamulus• Pterygomandibular raphae• Post end of mylohyoid line • Mucus membrane on side of tongue
Lower part covered by middle constrictor.
Superior Constrictor
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Middle Constrictor• Hypopharynx• O: lower part of stylohyoid ligament
lesser and greater cornu of hyoid
• Inferiorly overlapped by inferior constrictor.Mohamed el fiky
Inferior ConstrictorThickest of the 3Thyropharyngeus
O:oblique line of thyroid cartilageinferior cornu of thyroid
Cricopharyngeus
O: ant part of cricoid cartilage between attachment of cricothyroid and articulation of inferior cornu . *************************************qInsertion :All of the fibres get inserted into
the median fibrous raphae Extending from
Pharyngeal tubercle up to the oesophagus
qActions 0f the constrictor muscles : Muscles of 2 sides act as a sphincterFunction– prevent the entry of air into the oesophagus in the intervalbetween swallowing So sphincterrelaxes during swallowing Contractsbetween the acts of swallowing. Mohamed el fiky
Killian’s Dehiscence• Potential gap b/w weak area of pharyngeal wall • Gateway of Tear à perforation can occur at this
site during oesophagostomy.
Killian’s triangle
Laimer’s triangle
Inferior constrictor(cricopharyngeal part)
Inferior constrictor(thyropharyngeal part)
Fundiform part (cricopharyngeal sphincter,Killian’s sling)
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PHARYNGEAL SPACES
• 2 potential spaces in relation to pharynx:• Retropharyngeal space:
– Situated behind pharynx– Extends from base of skull to the bifurcation of
trachea• Parapharyngeal space:
– Situated on the side of pharynx– Contains carotid vessels, jugular veins, last four
cranial nerves & cervical sympathetic chainMohamed el fiky
Pharyngeal Plexus of Nerves• Almost all of the nerve supply to the pharynx, whether motor
or sensory, is derived from the pharyngeal plexus
• Formed by the pharyngeal branches of the glossopharyngeal(sensory )and vagus nerves (motor) with contributions from the superior cervical sympathetic ganglion.
all the muscles of the pharynx take nerve supply from The pharyngeal branch of the vagus except stylopharyngeus , which is supplied by the glossopharyngeal nerve
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Passavant’s Ridge• A mucosal ridge raised by fibres of
palatopharyngeus.• Forms a ring around post and lat walls of
nasopharyngeal isthmus.• When soft palate is elevated the muscle band
appear as a ridge àPassavant’s ridge• During act of swallowing palate and the ridge
approximated.
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Gaps in the pharyngeal wall
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RELATIONS (GAPS IN LATERAL WALL OF PHARYNX)
I-first gap : ( Above superior constrictor Between Base of the skull and Upper borderof the superior constrictor ) . It occupied by :
- Auditory tube.- Levator palati muscle.
II-second gap : Between : Lower border of the superior constrictor &Upper border of themiddle constrictor. . It occupied by :- Stylopharyngeus muscle.-Glossopharyngeal nerve.
III-third gap : Lower border of the middle constrictor& Upper border of the inferior constrictorIt occupied by :
- Internal laryngeal nerve . - Superior laryngeal artery.
IV-fourth gap :Below lower border of the inferior constrictorIt occupied by : - Recurrent laryngeal nerve.
- Inferior laryngeal artery.
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Nasopharynxxit shows the following features:Ø Opening of auditory tube .Ø Tubal elevation : it is the elevation formed by the upper and posteriormargins of the opening of the auditory tube.Ø Pharyngeal recess: is a depression in the pharyngeal wall behind thetubal elevationØ Salpingopharyngeal fold:§ It is a vertical fold of mucous membrane which runs downwards from the tubal elevation to the side wall of pharynx.§ It contains the salpingopharyneus muscle. Tubal tonsils: collections of lymph tissue near the tubal opening.
Mohamed el fiky
OropharynxxIt lies behind the oral cavity : extends from the soft palate above to the upper border of epiglottis below.
Palatine tonsilØ A large ovoid mass of lymphoid tissueØ It looks like a large almond.Ø It has :§ 2 poles : upper & lower§ 2 borders : anterior & posterior§ 2 surfaces : medial & lateralØ It has 12-15 tonsillar crypts which open on its medial surfaceq Position :Located in the tonsillar fossa on the lateral wall of oropharynx Ø The tonsillar fossa is bounded by :§ Anteriorly : the palatoglossal arch§ Posteriorly : the palatopharyngeal arch
Relations :Medial surfaceØ Covered by the mucous membraneØ Tonsillar pits are small orifices on the medial surface which lead into the tonsillar crypts.Latcral surface¡ Capsule :Ø Separates the tonsil from the superior constrictor of pharynx. Superior constrictor:Ø Separates the tonsil from:
1- The facial artery and its branches:
2- Para-tonsillar vein:
3- Glossopharyngeal nerve: Mohamed el fiky
Blood supply of the tonsil:Arteries :Ø Tonsillar branches of descending palatine arteryØ Tonsillar branch of the facial artery.Ø Tonsillar branches of ascending palatine artery. Ø Tonsillar branches of dorsal lingual artery. .= Veins :Ø Pharyngeal plexus of veins receives most of the veins.Ø Some veins drain into the lingual veinSensory nerve supply : lesser palatine (maxillary) andglossopharyngeal nerve.r Lymphatic srainage of the tonsil: Ø The deep cervical lymph nodes.
Waldeyer’s ring : is a tonsilar ring at the oropharyngeal isthmus , formed of linguinal , palatine ,
tubal and pharyngeal tonsils .
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Waldeyer’s Ringq The palatine tonsils,
nasopharyngeal tonsil (adenoid) and lingual tonsil constitute the
major part of Waldeyer's ring or nasal-associated lymphoid tissue (NALT), with the tubal tonsils and lateral pharyngeal bands as less prominent component
q A ring composed of NALT at beginning of food and air passage.
q Produce B and T lymphocytes
q Local defense
q Also produce lymphocytes to send to other lymph nodes.
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