Head/Neck Flashcards
Salivary glands
Parotid gland
Sublingual
Submandibular
Parotid gland: anatomic position
Lies in deep hallow: parotid region Superior: zygomatic arch Inferior: inferior border of mandible Anterior: masseter Posterior: external ear/sternocleidomastoid
Parotid gland: structure
Bilobed: deep and superficial lobes
Secretions are transported to oral cavity via Stensen duct (transversing master muscle)
Opens into cavity near second upper molar
Parotid gland: anatomical relationships
Facial nerve gives 5 terminal branches within parotid.
External carotid: ascends through parotid
Retromandibular vein: formed within gland by convergence of superficial temporal and maxillary veins
Parotid gland: blood supply
Post auricular artery
Superficial temporal artery
Parotid gland: venous drainage
Retromandibular vein
Parotid gland: innervation
Sensory: auriculotemporal nerve (gland), great auricular nerve (fascia)
Parasympathetic: glossopharyngeal nerve (CNIX)
Sublingual gland: structure & anatomical position
Small gland. Almond shaped. Joins other gland to form U-shape around lingual frenulum.
Situated beneath tongue in sublingual fossa
Lateral: mandible
Medial: genioglossus
Submandibular duct and lingual nerve travel medial to sublingual
Sublingual gland: drainage
Drains into oral cavity by minor sublingual ducts (of Rivinus): 8-20 ducts per gland.
Anatomical variance: sublingual papillae (large single duct)
Sublingual gland: blood supply
sublingual and submental arteries (branches from lingual and facial, from ECA)
Sublingual gland: venous drainage
Sublingual and submittal veins
Sublingual gland: innervation
Parasympathetic: CNVII –> chorda tympani
Sympathetic: superior cervical ganglion
Submandibular gland: anatomic position
In submandibular triangle
Superior: inferior body of mandible
Anterior: anterior belly of digastric
Posterior: posterior belly of digastric
Submandibular gland: Structure
Superficial arm and deep arm
Travel to oral cavity via submandibular duct (Wharton’s duct)
Submandibular gland: anatomical relationships
Lingual nerve: start lateral, loops beneath duct, terminating as several medial branches
Hypoglossal nerve: lies deep to gland and runs superficial to hypoglossus
Facial nerve: MM branch curves inferior to gland
All can be damaged during excision of SM gland
Submandibular gland: blood supply
Submental artery
Submandibular gland: venous drainage
Facial vein
Sublingual vein
Submandibular gland: innervation
Parasympathetic: CNVII –> chorda tympani
Symp: superior cervical ganglion
Salivary gland tumours
Benign: pleomorphic adenoma, Warthin’s tumour
Malignant: Mucopeidoermoid carcinoma, Adenoid Cystic Carcinoma, acinic cell carcinoma, SCC, adenocarcinoma
Parotid: 80/20 benign/malignant
Submand: 50/50
Sublingual: 20/80
Sialolithiasis
Calculi in salivary glands/ducts
Calcium phosphate or hydroxyapatite stones
RF: drugs (diuretics/anti-cholinergics), dehydration, gout smoking, hyperPTH
Sx: intermittent pain/swelling
Sialadenitis
Inflammation of salivary gland
Causes: infective (viral: mumps), stones, malignancy, automimmune (sarcoid, Sjogren’s)
Tonsils
Pharyngeal tonsil
tubal tonsils (x2)
Palatine tonsils (x2)
Lingual tonsil
Mucosa associated lymphoid tissue: MALT
Lingual tonsil
Location: submucosa of posterior 1/3 tongue
Blood supply: lingual artery
Nerve: glossophyaryngeal (CNIX)
Lymph: jugulodiagastric/deep cervical
Pharyngeal tonsil
Roof of nasopharynx
Covered by ciliated pseudostratified epithelium
Blood supply: ascending palatine. ascending pharyngeal, Pterygoid canal. tonsillar branch of facial
Venous: pharyngeal plexus
Lymph: retropharyngeal nodes
Tubal tonsils
Around opening of Eustachian tube in lateral wall of nasopharynx
Blood: ascending pharyngeal
Venous: pharyngeal plexus
Nerve: maxillary, glossopharyngeal nerves
Lymph: retropharyngeal/deep cervical
Palatine tonsils
Location: Tonsil bed of lateral oropharynx between palatoglossal arch (anterior) and palatopharyngeal arch (posterior)
Covered by stratified non-keratinised squamous epithelium
Blood: tonsils branch of facial
Venous: external palatine vein
Nerve: maxillary, glossopharyngeal
Lymph: jugulodigastric/deep cervical
Post tonsillectomy bleeding
5%
Primary: <24hrs. Loosened sutures
Secondary: >24hrs. Infection, collection
Parts of the ear
External ear
Middle ear
Inner ear
Parts of external ear
Auricle
External acoustic meatus
Tympanic membrane
Parts of the auricle
Helix: outer curvature Antihelix Superior crus Inferior crus Concha: middle hollow depression Tragus: elevation immediate anterior to EAM Antitragus Lobule
External acoustic meatus
Sigmoid shaped tube: S shaped curve
Extends from deep part of concha to tympanic membrane
External 1/3: cartilage walls
Inner 2/3: temporal bone forms walls
Tympanic membrane
Connect tissue with skin on outside. Membranous inside. Parts: Lateral process Handle of malleus Umbo Pars tensa
Blood supply to external ear
Branches of external carotid: Post. auricular Superficial temporal Occipital Maxillary
Innervation to external ear
Sensory:
Greater & lesser auricular nerves (from C-plexus): skin of auricle
Auriculotemporal n. (CNV3) skin of auricle and external auditory meatus
Branches of vagus and facial also innervate deeper aspects of auricle and external auditory meatus
Parts of the middle ear
Tympanic cavity
Epitymanic recess
Borders of middle ear
Roof: petrous part of temporal Floor: jugular wall Lateral: tympanic membrane Medial: lateral wall of inner ear Anterior: thin bony plate w. 2 openings (auditory tube and tensor tympani) Posterior: Mastoid wall
Bones of the middle ear
“Auditory ossicles”
Malleus
Incus
Stapes
Mastoid air cells
Located posterior to epitympanic recess
Collection of air filled spaces in mastoid process of temporal bone
Acts as “buffer” releasing air into tympanic cavity when pressure it too low
Muscles of middle ear
Tensor tympani (tesnor tympani nerve, CNV3) Stapedius (nerve to stapedius, CNVII)
Function: protection of middle ear
Contract in response to loud noise, inhibiting vibrations of malleus, incus and stapes. reducing sound transmission to inner ear.
Auditory tube
“Eustachian tube”
Cartilaginous and bony tube that connects middle ear to nasopharynx
Equalise pressure
Parts of inner ear
Bony labyrinth
Membranous labyrinth
Bony labyrinth
Series of bony cavities within petrous part of temporal bone
Cochlea
Vestibule
3 semi-circular canals
Membranous labyrinth
Continuous duct system filled with endolymph
Cochlear duct
Saccule & Utricle
Semi-circular ducts
Blood supply to inner ear
Bony:
Anterior tympanic branch (maxillary artery)
Petrosal branch (middle meningeal, from Maxillary)
Stylomastoid branch (from posterior auricular)
Membranous:
Labyrinthine artery
Innervation to inner ear
Vestibulocochlear nerve
Rinne’s test
- Place tuning fork (512Hz) on mastoid. Tests bone conduction.
- Pt confirms they can hear it and says when its stops.
- When cannot hear it move to external auditory meatus. Tests air conduction.
- Ask if they can still hear (If yes: normal)
Air conduction > bone (Rinne’s positive): normal/sensorineural
Bone > air (Rinne’s negative): conductive deafness
Weber’s test
- 512Hz tuning fork placed in midline of forehead
- Ask where patients hears sound
Normal: equal in both ears
Sensorineural: louder on intact
Conductive: louder on affected
Conductive hearing loss
Impacted earwax Foreign body Tympanic membrane perforation Infection: otitis externa/media Cholesteatoma Middle ear effusion Otosclerosis Neoplasm (SCC of external ear) Exostoses
Sensorineural hearing loss
Age-related hearing loss NIHL Meniere's Ototoxic substances (amino glycoside substances), loop diuretics, anti-malarial, cytotoxic (cisplatin, bleomycin) Labyrinthitis Vestibular schwannoma (acoustic neuroma) Neuro: MS/stroke Malignancy Autoimmune: RA, SLE, sarcoid Hereditary: Alport's
Acute otitis externa
Infection of external ear
RF: water exposure (swimming), trauma to canal, blockage
Sx: red, swollen, tender canal
Cause: Pseudomonas (40%), Staph epidermis/aureus. Can be fungal.
Brighton Grading System I-IV
Rx: topic Abx
Acute Otitis media
Bacterial infection of middle ear resulting from nasopharyngeal organisms migrating via Eustachian tube
Cause: Strep pneumoniae (most common), H influenza, M catarrhalis
RF: age (6-15mths), M>F, parental smoking, bottle feeding
Sx: pain, malaise, fever, coryzal
TM redness and bulging
Complications: CNVII involvement, intracranial complications, mastoiditis
Rx: conservative if uncomplicated. Abx for unwell, RFs. Mastoiditis: IV abx +/- mastoidectomy
Otitis media with effusion
“Glue ear”
Build up of viscous inflammatory fluid in middle ear
Sx: conductive hearing impairement
TM appears dull +/- bubble seen
Rx: 50% resolve in 3 months
Surgical: myringotomy + grommet insertion
Non-surg: hearing aid insertion
Cholesteatoma
Abnormal sac of keratinising squamous epithelium and accumulation of keratin in middle ear.
Sx: persistent, recurrent ear discharge
Complications: local destruction of ossicles (conductive HL), semicircular canals (vertigo), cochlea (sensorineural HL), facial canal (CNVII palsy)
Acoustic neuroma (vestibular schwannomas)
Benign tumours from Schwann cells surrounding vestibulocochlear n. (CNVIII). Slow growing.
Vestibular portion most commonly affected (80%). 80% at cerebellopontine angle.
RFs: NF2 (bilateral)
Sx: triad of: unilateral SNHL, tinnitus, vertigo. Sx of raised ICP: headache, seizures.
Rx: MRI monitoring. Stereotactic radio surgery. Surgical resection.
Vertigo
Central: MS Posterior stroke Migraine SOL Otological: BPPV Meniere's Vestibular neuronitis
