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Home , Canal (anatomy), Foramen rotundum, Greater petrosal nerve, Inferior nasal concha, Inferior orbital fissure, Lacrimal nerve

Pharynx, , And Pterygopalatine

Mikel H. Snow, Ph.D. Dental [email protected] July 29, 2018

Food & Air Passage Pharynx The pharynx is a tube that opens anteriorly with 3 regions. The upper part communicates with nasal cavity, the middle communicates with oral cavity, and the lower communicates with the larynx.

Nasal cavity

Nasal Oral cavity cavity Larynx

Air Nasopharynx: between Oral sphenoid & uvula Food/ cavity Oropharynx: between uvula & epiglottis drink

Laryngopharynx: between epiglottis &

Esophagus The posterior and lateral walls are 3 skeletal muscles (constrictors) that propel food/liquid inferiorly to the esophagus. Constrictors innervated by CNX. Additional muscles elevate the pharynx (stylopharyngeus is external). Stylopharyngeus innervated by CNIX.

Stylopharyngeus Superior constrictor Middle constrictor Inferior constrictor Two additional internal muscles we’ll get to later… Key relationship: Glossopharyngeal wraps around stylopharyngeus muscle.

CN IX wraps around stylopharyngeus muscle and Stylopharyngeus innervates it.

Pharyngeal constrictors Pharynx Interior

1 Nasopharynx: 1. Pharyngeal tonsils 2. Auditory tube ostia 2 3 3. Salpingopharyngeal fold 4 4 Oropharynx: 4. Palatine tonsils

5 5 Laryngopharynx: Slit open 5. Piriform recess constrictors to examine interior Lateral Wall of Pharynx 5. Salpingopharyngeus muscle 6. Levator veli palatini muscle 1. Pharyngeal tonsils 7. Tensor veli palatini muscle 2. 8. 3. Auditory tube opening 9. Palatoglossal fold/muscle 4. Salpingopharyngeal fold 10. Palatopharyngeus fold/muscle 1 Nasal 2 3 cavity 1 7 2 6 3 5 4 Oral 9 10 cavity 9 8 10 Summary Rule for Innervation of Muscles of Pharynx and

All muscles of the pharynx and palate are innervated by the , except: • Stylopharyngeus which is IX

• Tensor veli palatini which is V3 Sensory Innervation to Pharynx

Glossopharyngeal “Gag Reflex”

Vagus Larynx

Vocalization Laryngeal and Ligaments

Larynx functions in phonation & respiration Epiglottis Hyoid Internal br. superior laryngeal n. Thyrohyoid membrane Arytenoids

Thyroid

Arytenoid cartilages (ghosted in)

Cricoid cartilage

Trachea Cricothyroid membrane Laryngeal Cartilages and Ligaments

Epiglottis

Vestibular ligament

Thyroid When covered with Arytenoid mucosa they become folds. Vocal ligament Cricoid Emergency cricothyrotomy The interior of the larynx is covered by mucosa and divided into upper (supraglottic) and lower (infraglottic) regions by the glottis. What is the glottis? Vestibular Supraglottic region Right & left vocal fold, left Innervated by internal br. superior laryngeal n. cords plus space in between them.

Vocal ligament, right Glottis changes dimensions Infraglottic region during respiration/phonation. Innervated by recurrent laryngeal n. Vocal Cords While Singing Right Vocal Cord Paralysis The 11 laryngeal skeletal muscles function to ADDUCT, ABDUCT and adjust TENSION on the vocal cords during phonation and respiration. You are only responsible for two: cricothyroid and posterior cricoarytenoid.

Synovial Tenses Abducts joint

Cricothyroid Posterior cricoarytenoid External branch of Recurrent laryngeal nerve The right & left ventricles are small pockets between vestibular & vocal folds. They are rich in mucous that moisten the vocal cords.

Epiglottis

Arytenoid

Cricoid Coronal section

Opening into ventricle Nasal Cavity

Olfaction and Respiration Nasal Cavity

Roof:

Lateral walls: Concha (turbinates)

Three conchae project Floor: medially from lateral wall to create more surface area for humidifying & adjusting air temperature. There are 4 pairs of , each named according to the they lie in:

Frontal

Sphenoid Ethmoid

Maxillary

Mucosa lining sinuses produces nitric oxide which is antiviral and bacteriostatic. Thereby they assist immune system. Nasal Cavity Osteology Lateral Wall

Frontal Bone : 1. cribriform plate 2. superior concha 3. middle concha 1 2 6 3 10

4 Inferior 9 : 5 9. med. pterygoid plate 7 10. : 8 6. nasal surface 7. palatine : 8. 4. perpendicular plate 5. horizontal plate Nasal Cavity

Superior concha

Middle concha

Auditory? tube opening

Inferior concha

A is the space immediately lateral to a concha. Drainage Ostia Within Nasal Cavity

Sphenoethmoidal: Sphenoid sinus

Semilunar Superior meatus: hiatus Ethmoids (post.)

Middle meatus: Ethmoids (ant & mid)

Inferior meatus: Nasal Cavity

Mucosal Innervation: Sensory V1 & V2

1. nasal branches of 2. anterior ethmoidal br. of

3. lateral nasal branches 2 4.

1 3 1 3 V1 V1 3 4 V V2 2 3 3 4 4. Passes thru incisive to innervate maxillary anterior teeth. Lateral Wall Septum Nasal Cavity: Blood Supply Blood supply is via the maxillary which passes thru pterygopalatine fissure to give rise to 3 terminal branches: 1. sphenopalatine, 2. descending palatine and 3. infraorbital. 1

3

2 Nasal Cavity: Blood Supply These anastomose within nasal cavity, representing an anastomosis between external and internal carotid arteries.

Epistaxis = Anterior & posterior ethmoids Branches of ophthalmic (ICA) Sphenopalatine (ECA)

Branches of facial (ECA)

PT Fossa, V2 & Pterygopalatine Fossa Small, cone-shaped fossa with 6 openings: 1 laterally, 1 medially, 1 anteriorly, 1 inferiorly and 2 posteriorly.

Houses , V2 & terminal branches of maxillary artery.

1 2

Lateral View Medial View 1. 2. Sphenopalatine foramen Once you break plane of fissure you Opening from pterygopalatine are in pterygopalatine fossa. fossa into nasal cavity. Transmits maxillary artery Transmits Two Posterior Openings

V2

4. 3. Transmits Transmits (Vidian’s nerve) How to cannulate the pterygoid canal

Medial pterygoid plate

Pterygoid canal

Foramen magnum Inferior Opening in PT Fossa

5. palatine canal Transmits greater & lesser palatine & descending palatine artery; exits are greater & . One Anterior Opening Leading Out of in PT Fossa

6. Transmits Summary of 4 openings in PT Fossa

Sphenopalatine foramen Foramen rotundum Pterygoid canal

Palatine canal

Inferior orbital fissure Pterygopalatine Ganglion: Para/pre Para/post

Greater petrosal nerve from facial

Geniculate ganglion

VII Pterygopalatine Ganglion: Para/pre Para/post

1. Lateral nasal branches 4. Branch to maxillary n. V 2 Greater petrosal nerve from facial

1 4

Mucosal 1 glands Sympathetics Mucosal 1 2 Nerve of pterygoid glands 3 canal (Vidian’s nerve)

3. Lesser palatines 3 2 Paltine glands

2. Great Thus, lacrimal is innervated by VII via PT ganglion.

1. Anterior 2. Middle Superior alveolar nerves 3. Posterior Hitchhiking on

1 Mucosa maxillary 2 3 sinus Any Questions?