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.

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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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