Head and Neck Anatomy (7th copy) PDF

Oral Cavity Relations: Oropharynx - oropharyngeal isthmus Nasal cavity - maxilla (incisive canal) External - oral fissure Oral Cavity - Boundaries and Structures Roof Hard and soft palate Floor Muscles: both paired, working to open mouth Mylohyoi...

Oral Cavity Relations: Oropharynx - oropharyngeal isthmus Nasal cavity - maxilla (incisive canal) External - oral fissure Oral Cavity - Boundaries and Structures Roof Hard and soft palate Floor Muscles: both paired, working to open mouth Mylohyoid (forming diaphragm) ○ From hyoid bone to molar (mylo) ○ n. to mylohyoid from inferior alveolar branch of mandibular n. [V3] Geniohyoid (above mylohyoid) ○ From hyoid bone to chin (genio) ○ C1 hitchhiking from neck along hypoglossal n. Tongue Sublingual and submandibular glands and ducts Lateral Cheeks - mainly buccinator Anterior Oral fissure - Lips - Philtrum, formed by fusion of medial nasal processes - Median labial frenulum - connecting lip to gum Posterior Oropharyngeal isthmus - formed by palatoglossal arches, opened/closed by soft palate and tongue Oral Cavity - Boundaries and Structures Roof Hard and soft palate Floor Muscles: both paired, working to open mouth Mylohyoid (forming diaphragm) ○ From hyoid bone to molar (mylo) ○ n. to mylohyoid from inferior alveolar branch of mandibular n. [V3] Geniohyoid (above mylohyoid) ○ From hyoid bone to chin (genio) ○ C1 hitchhiking from neck along hypoglossal n. Tongue Sublingual and submandibular glands and ducts Lateral Cheeks - mainly buccinator Anterior Oral fissure - Lips - Philtrum, formed by fusion of medial nasal processes - Median labial frenulum - connecting lip to gum Posterior Oropharyngeal isthmus - formed by palatoglossal arches, opened/closed by soft palate and tongue Oral Cavity - Boundaries and Structures Roof Hard and soft palate Floor Muscles: both paired, working to open mouth Mylohyoid (forming diaphragm) ○ From hyoid bone to molar (mylo) ○ n. to mylohyoid from inferior alveolar branch of mandibular n. [V3] Geniohyoid (above mylohyoid) ○ From hyoid bone to chin (genio) ○ C1 hitchhiking from neck along hypoglossal n. Tongue Sublingual and submandibular glands and ducts Important relation: lingual nerve underneath submandibular duct Lateral Cheeks - mainly buccinator Anterior Oral fissure - Lips - Philtrum, formed by fusion of medial nasal processes - Median labial frenulum - connecting lip to gum Posterior Oropharyngeal isthmus - formed by palatoglossal arches, opened/closed by soft palate and tongue Hard Palate Made up of maxilla bone (palatine process) and palatine bone (latter ¼) Covered by respiratory mucosa (nose) above and oral mucosa (mouth) below Foramina: incisive canal, greater/lesser palatine foramina Palatine raphe (median) running to the incisive papilla is on top of the intermaxillary suture running to the incisive canal Soft Palate The posterior portion of the roof made up of soft tissue Functions as a valve: ○ Depression closes oropharyngeal isthmus (isolates mouth) e.g. holding water in mouth ○ Elevation separates nasopharynx from oropharynx (isolates nose) e.g. mouth breathing Uvula hangs at back The soft palate is associated with 4 (5?) muscles: Tensor veli palatini Levator veli palatini Palatoglossus Palatopharyngeus (also musculus uvulae) Soft Palate Muscles All innervated by vagus nerve [X] via pharyngeal branch to pharyngeal plexus EXCEPT tensor veli palatini - mandibular nerve [V3] via branch to medial pterygoid Palatoglossus is anterior to palatopharyngeus ○ Glossus = tongue, anterior to pharyngeus = throat ○ Forms the palatoglossal/palatopharyngeal arches with the palatine tonsil resting in between ○ Acts to depress soft palate/ or pull the pharynx up, forward, medially during swallowing ○ Palatoglossus is attached to palatine aponeurosis and draws tongue and palate together (palat-glossus) Soft Palate Muscles All innervated by vagus nerve [X] via pharyngeal branch to pharyngeal plexus EXCEPT tensor veli palatini - mandibular nerve [V3] via branch to medial pterygoid Palatoglossus is anterior to palatopharyngeus ○ Glossus = tongue, anterior to pharyngeus = throat ○ Forms the palatoglossal/palatopharyngeal arches with the palatine tonsil resting in between ○ Acts to depress soft palate/ or pull the pharynx up, forward, medially during swallowing ○ Palatoglossus is attached to palatine aponeurosis and draws tongue and palate together (palat-glossus) Tensor veli palatini (TVP) is anterior to levator veli palatini ○ Both elevate soft palate but only LVP above neutral - think levator to elevate ○ TVP comes from above wraps around pterygoid hamulus before attaching at the palatine aponeurosis ○ TVP opens the pharyngotympanic tube during yawning/swallowing Musculus uvulae pulls uvula superiorly Palate - Neurovasculature Arteries: Greater and lesser palatine arteries Maxillary artery gives off greater palatine branch, which gives off lesser palatine branch in palatine canal Travel through greater and lesser palatine foramen (in palatine bone) respectively Greater branch → hard palate → incisive canal Lesser branch → soft palate → uvula Veins follow arteries and drain into pterygoid or pharyngeal plexus Lymphatics: deep cervical nodes Innervation: branches of pterygopalatine ganglion Greater/lesser palatine nerve (hard and soft palate respectively) Nasopalatine nerve (through incisive canal) Note the ganglion recieves branches from: ○ Maxillary n. [V2] - general sensory ○ Facial n. [VII] - PNS to glands and taste to soft palate ○ T1 sympathetic trunk - SNS Teeth and Gingivae (Low yield) Teeth are attached to alveoli (sockets) in gingivae (gums) Adults have 32 teeth - on each quadrant: 2 incisors, 1 canine, 2 premolar, 3 molar Deciduous teeth emerge between 6M-2Y (with no premolars and 2 molars) Permanent teeth ~ 6Y Arterial supply: superior and inferior alveolar a., lingual a., nasopalatine, greater palatine a. - all branches of maxillary a. Veins follow arteries → pterygoid plexus Lymphatics → deep cervical nodes Innervation: ○ Upper jaw = V2 via superior alveolar n. ○ Lower jaw = V3 via inferior alveolar n. And buccal n.  Tongue (glossus) Structure: Terminal sulcus: ○ Separates oral and pharyngeal surfaces (⅔ from the apex) ○ Margin of oropharyngeal isthmus ○ Apex of V is foramen cecum (site of invagination to form thyroid gland, when the thyroglossal duct persists, thyroid gland is here) Divided left/right by median sagittal septum Papillae on the oral surface increases SA ○ All except filiform have taste buds on surface Lingual tonsil sits on pharyngeal surface Inferior surface from medial to lateral has: frenulum → lingual v. → fibriated fold  Tongue - Muscles All paired All supplied by hypoglossal nerve [XII] EXCEPT palatoglossus by vagus nerve [X] (considered part of palate muscles) Intrinsic muscles: alter shape of tongue by lengthening/ shortening, curling, flattening Superior and inferior longitudinal Transverse and vertical Extrinsic M Attachment Action Genioglossus Superior mental spines Depress central part (genio= chin) Poke tongue out Hyoglossus Hyoid bone (greater horn Depress ish) Styloglossus Styloid process Elevate and retract Important relation: (from inner to outer) Palatoglossus Inferior surface of Elevate Genioglossus → lingual a → Hyoglossus → palatine aponeurosis + depress soft palate hypoglossal/lingual n.  Tongue - Muscles Extrinsic M Attachment Action Genioglossus Superior mental spines Depress central part (genio= chin) Poke tongue out Hyoglossus Hyoid bone (greater horn Depress ish) Styloglossus Styloid process Elevate and retract Important relation: (from inner to outer) Palatoglossus Inferior surface of Elevate Genioglossus → lingual a → Hyoglossus → palatine aponeurosis + depress soft palate hypoglossal/lingual n.  Tongue - Vessels Branches of lingual artery (enters through oropharyngeal triangle and travels above genioglossus, under hyoglossus) Dorsal lingual a./v. - back Deep lingual a./v. - inferior surface of tongue (travels with hypoglossal n.) Sublingual a./v. - underneath tongue Lymphatic drainage → deep cervical and submental l.n. Tongue - Innervation (HIGH YIELD) IMPORTANT Issue with vagus [X] = Uvula deviate toward normal side Issue with hypoglossal n. [XII] = Tongue deviates toward abnormal side Motor Muscles of tongue Hypoglossal n. [XII] Palatoglossus Vagus n. [X] Sensory Anterior ⅔ Trigeminal [V] - general sensation Facial [VII] via chorda tympani - special sensation (taste) Posterior ⅓ Glossopharyngeal [IX] - general and special sensory Epiglottis and soft palate Vagus n. [X] - general and special Tongue - Innervation (HIGH YIELD) Reasoning: Hypoglossal [XII] = muscles of tongue as hypo = under, and nerve runs underneath tongue to access all the muscles Vagus [X] is all of palate (except TVP) therefore: motor to palatoglossus and sensory to epiglottis and soft palate General sensory is same as surroundings ○ Closest to face (ant ⅔) = trigeminal [V] ○ Closest to pharynx (post ⅓) = glossopharyngeal [IX] Taste is provided by same sensory nerve except anterior ⅔ of tongue via facial nerve [VII] chorda tympani  Salivary Glands Mostly small glands in submucosa or mucosa of oral epithelium. Larger glands (parotid, submandibular, sublingual) are paired:  Salivary Glands Mostly small glands in submucosa or mucosa of oral epithelium. Larger glands are paired: Parotid Gland Submandibular Gland Sublingual Gland Relations Deep and superficial lobes separated by facial nerve Curls around mylohyoid (diaphragm) Pierced by (from superficial → deep): Facial artery loops over superficial lobe Facial nerve [VII] → 5 terminal branches (between lobe and mandible) Retromandibular vein External carotid artery Lingual nerve loops under duct Lymph nodes Duct opens to 2nd upper molar Sublingual caruncle (beside frenulum) Numerous along sublingual fold Arteries External carotid artery Facial and lingual artery/vein Veins External jugular vein Lymphatics Parotid nodes → deep/superficial cervical Submandibular nodes → deep cervical Innervation Sensory: Auriculotemporal n. [V3] and greater auricular n. PNS: Chorda tympani of facial [VII] PNS: glossopharyngeal [IX] via otic ganglion → auriculotemporal n. SNS: T1 via external carotid  Salivary Glands Mostly small glands in submucosa or mucosa of oral epithelium. Larger glands are paired:  Surgery of Salivary Glands Parotidectomy can cause injury to facial nerve presenting as: Surgery of submandibular gland Weakness of facial muscles When working on the submandibular duct, beware Complete palsy: inability to close eye/blink → dry injury to lingual nerve which loops underneath eye/inflammation → ulceration of cornea When removing whole gland beware marginal mandibular branch of facial n. and lingual n. Mumps Definition Viral infection that affects salivary glands (parotid gland most common) Sx Acute/tender parotid swelling Pain on chewing food Fever Headache, fatigue Weight loss CCs Facial nerve → difficulty with facial expressions Localised ear pain due to swelling of parotid