Head and Neck Flashcards
What are the borders of the posterior triangle of the neck?
Posterior SCM
Anterior trapezius
Clavicle
Nuchal line of occiput
What are the borders of the anterior triangle of the neck?
Inferior mandible
Imaginary midline
Jugular notch of sternum
Medial edge of SCM
What is the origin and insertion of trapezius?
Nuchal line of occiput
Lateral 1/3 of clavicle
What are the sub triangles of the anterior triangle?
Submental (medial to anterior belly of digastric, superior to hyoid)
Submadibular (between anterior and posterior belly of digastric)
Carotid (between posterior belly of digastic and omohyoid)
Muscular (medial to omohyoid)
What is found in the submental triangle?
Small lymph nodes
Origin of anterior jugular vein
What is found in the submandibular triangle?
Lymph nodes and submandibular gland
What is found in the carotid triangle of the neck?
Carotid artery in sheath with vagus nerve and ijv
Deep cervical lymph nodes
What is found within the muscular triangle of the neck?
Infrahyoid muscles
Vicera of the neck
At what level does the carotid artery bifurcate?
Superior thyroid cartilage (C4)
What are the actions of sternocleidomastoid
Bilateral contraction lifts chin
Unilateral contraction flexes neck laterally and rotates head so ear moves to ipsolateral shoulder
What is in the posterior triangle of the neck?
Ejv
Cnxi
Roots of brachial plexus
What is the subcutanious tissue of the neck also known as?
Superficial cervical fascia
What are the subdivisions of the deep cervical fascia?
Investing fascia
Prevertebral fascia
Pretrachial fascia
Carotid sheath
What muscles are found within the superficial cervical fascia and the investing cervical fascia?
Platysma
Scm and trapezius
Where does the pretracheal fascia extend from and too?
From the hyoid to the fibrous pericardium
How can the pretracheal fascia be subdivided?
Visceral and muscular
Visceral is continuous with the buccopharangeal fascia and contains oesophagus, trachea and thyroid
Muscular sits anteriorly containing the infrahyoid muscles.
Where does the preverterbral fascia run?
Encompasses the vertebral column and muscles, fixed to the cranial bone superiorly and is continuous with the thoracic fascia and axillary sheaths inferiorly
Where do the carotid sheaths blend?
With the pretracheal fascia medially, investing fascia laterally and the preveterbral fascia posteriorly
What are the functions of the cervical fascia?
Compartmentalise contents
Allow movement
Contain infection
What is more serious, a reteropnayngeal abscess or parapharangeal abscess? Why?
Reteropharyngeal - space opens directly into mediastinum whilst parapharyngeal space stops at level t2/3
Which is more common, reeteropharangeal abscess or parapharyngeal abscess?
Parapharyngeal
What tends to preceed retro and parapharyngeal abcesses?
Retro - urti
Para - tonsilitis
What fascia sits in the retropharyngeal space?
Alar fascia
What are the superficial and deep infrahyoid muscles?
What innervates them?
Superficial
Omohyoid - C1 to C3 branch of ansa cervicalis
Sternohyoid - C1 to C3 branch of ansa cervicalis
Deep
Sternothyroid - C1 via hypoglossal nerve
Thyrohyoid - C2 to C3 branch of ansa cervicalis
What are the functions of the infrahyoid muscles?
Depress the hyoid.
Thyrohyoid can elevate the larynx
Sternothyroid can depress the larynx
What are the suprahyoid muscles and their innervation?
Mylohyoid - n. to mylohyoid b.o. inferior alveolar n. b.o. CNV3
Geniohyoid - C1 via hypoglossal n.
Stylohyoid - stylohyoid branch of facial nerve
Anterior belly of digastric - nerve to mylohyoid
Posterior belly of digastric - digastric branch of facial nerve
What is the path and function of the olfactory nerve?
Special sense smell
Olfactory receptors, through cribiform plate into olfactory bulb, pass back down the olfactory tract to the cerebrum
Where do the optic tracts terminate (most fibres?)
Lateral geniculate nucleus of thalamus
Why does increased icp cause papilloedema?
The nerve is actually a tract covered in meningies and csf. Raised icp impairs drainage causing papilloedema
What is the autonomic nucleus of cn iii called?
Edinger westphal or accessory
Where do the three branches of the trigenminal nerve leave the cranium
V1 - superior orbial fissure
V2 - foramen rotundum
V3 - foramen ovale
What are the muscles of mastication?
Temporalis
Masseter
Medial and lateral pterygoids
Other than the muscles of mastication which other muscles does CNV3 supply?
Anterior digastric
Tensor tympani
Which nerves are associated with the cavernous sinus?
Cn 3 - 6
What is special about the abducens nerve?
Long intradural course
Which nerves pass through the superior orbital fissure?
Occulomotor
Trochlea
Parts of cnv1 (lacrimal, supra orbital, nasocilary)
Abducent
What areas of senation are provided by the facial nerve?
Anterior 2/3rds taste
General sensation around eam of external ear
What is the course of the facial nerve?
Motor and sensory/autonomic (intermediate nerve) roots leave the pons
Transverse the IAM before turning sharply in the temporal bone forming the geniculate ganglion
Pass through the bone giving off greater petrosal nerve, nerve to stapedius and chorda tympani.
Exits the stylomastoid foramen
Gives off posterior auricular nerve
Splits into 5 facial motor branches (temporal, zygomatic, buccal, mandibular, cervical)
What branch of the facial nerves are associated with which autonomic ganglions?
Greater petrosal to the pterygopalatine
Chorda tympani to the submandibular
What autonomic does the facial nerve provide (and from which ganglions?
Pterygopalatine - lacrimation, mucus membranes of sinuses and nasopharynx
Submandibular - SM and SL glands
By which nerve do postganglionic fibres travel from the pterygopalatine to the lacrimal glands?
The lacrimal branch of CNV2
Differentiate upper and lower motor neurone causes of facial paralysis - why?
Upper is forehead sparing as there is bilateral innervation to both facial nerve nuclei from the cerebral hemisphere (thus both umn tracts would have to be damamge)
Lower effects forehead as there is no collateral innervation from CNVII
What effect may a proximal facial nerve lesion have on hearing? What about distal?
May make you sensitive to low tones as reduced dampening from stapedius
Distal will have no effect on hearing
Which cranial nerves arise from which areas of the brain and brainstem?
Cerebral - i, ii Midbrain - iii, iv Pons - v, vi, vii, Pons/medulla - viii Medulla - ix, x, xii Medulla and spine - xi
What are the ganglia of the vestibulocochlea nerve?
Vestibular - vestibular ganglion
Cochlea - spiral ganglions
What are the tuning fork tests for hearing?
Rinne’s - is bone conduction louder than air (if so obstructive defect in that ear)
Weber’s - in which ear is a central vibration louder (if louder in ear with loss obstructive defect in that ear, if louder in ear without loss sensorineural defect in ear with loss)
What sensation is provided by the. Glossopharyngeal nerve?
Taste and sensation (posterior 1/3)
Sensation in euctachian tube and inner tympanic membrane
Baro and chemo receptors at arch of aorta
Sensation of oropharynx and throat
Gag reflex
What motor and autonomic innervation is. Provided by cnix (with ganglion)
Stylopharynegeus Parotid gland (otic)
Through which foramen does the glossopharyngeal nerve leave the cranium?
Jugular foramen
Which branch of the glossopharyngeal nerve goes to the otic ganglion?
Tympanic!
What are the four branches of the cranial nerves that supply sensation to the ear?
Auricular temporal - trigeminal
Posterior auricular - facial
Tympanic - glossopharyngeal
Auricular - vagus
What sensation is derived from the vagus nerve?
Inferior pharynx and larynx
Root of Tongue and epiglottis
Viceral sensation from thorax and abdomen
Aortic bodies and sinuses
What is the motor innervation of the vagus
Soft palate
Pharynx
Intrinsic laryngeal muscles
Palatoglossus
Through which foramen does the vagus exit the cranium
Jugular
What are the three branches of the vagus that supply the larynx? What do they do?
Superior laryngeal branches into external laryngeal (motor to cricothyroid) and internal laryngeal (sensation to internal larynx)
Recurrent laryngeal becomes inferior laryngeal (all intrinsic laryngeal muscles except cricothyroid)
What is the course of the acessory nerve?
Branches of c1-5 merge with cnx outside jugular foramen then seperate again crossing scm down to trapezeus
How does the hypoglossal nerve leave the cranium?
Hypoglossal canal
How do sympathetic fibres reach the head and neck?
Leave t1-l2 by the anterior root, travel through the white rami communicates, enter sympthetic trunk ganglia where they ascend to the cervical ganglion
What is innervated by the superior cervical ganglion? What arteries do these nerves follow?
Sweat glands, pulpils, levator palpebrae superioris, nasal glands, salivary glands
Via carotids
What do the nerves of the middle cervical ganglion innervate? What arteries do they follow?
Larynx, trachea, hypopharynx, oesophagus
Via the inferior thyroid artery
What is the clinical consequence of the close association between the sympathetic nerve nerve supply to han and arteries?
Aneurysm can damage them
What are the specific features of the cervical vertebra?
Stubby transverse process Triangular vertebral foramen Foramen for vertebral artery Bifid spine (c3-6) Horizontal articular processes
What is special about the atlas and axis?
What movements do they allow?
Atlas - no spinous process or body
Axis - ordontoid peg
Atlas and occiput joint allows nodding
Axis and atlas joint allows shaking
What are the parts of the neurocranium?
Calvaria
Base
What are the three sutures and two joins of the calvaria?
Coronal suture
Saggital suture
Lamboid suture
Bregma (coronal and saggital join)
Lambda (saggital and lamboid join)
What makes the cranial sutures strong?
Synathrotic fibrous sutures
Serrated edges allowing interlocking.
What is the middle layer of a skull bone termed?
Diploe
What are two weak areas of the cranium?
Pterion (joint of parietal, frontal, temporal and sphenoid)
Base (due to many foramen)
When do the fontanelles close? What do they form?
How can the adult form be useful clinically?
Anterior closes to bregma - closes by 18 months
Posterior closes to lambda - closes by 12 months
Used as radiological landmarks
What is the advantage of a baby having unfused sutures?
Allows skull compression on delivery
What are the two processes at the top of the madibular ramus from anterior to posterior?
Coronoid
Condylar
What are the 6 sections of the temporal bones?
Squamous Mastoid Tympanic Styloid Zygomatic process Petrous
Which parts of the ear are contained within the petrous temporal bone?
Tympanic cavity, eustachian tube, inner ear
What is located posterior to the tragus in the external ear?
Concha
Antitragus
What are the two ridges that make up the majority of the auricle?
Helix
Antihelix
What is the arterial supply to the external ear?
Superficial temporal
Posterior auricular
What is the nervous innervation to the external ear?
Great auricular nerve (C2/C3) to posterior auricle
Auricular temporal branch of CNV2 to anterior auricle, superior/inferior surface of EAM and external tympanic membrane
Auricular branch of CNX to concha and inferior posterior surface of EAM
Posterior auricular branch of CNVII to concha and antihelix
Tympanic branch of glossopharyngeal to internal tympanic membrane and eustachian tube
What are the different parts of the EAM made of?
External 1/3rd elastic cartilage with skin continuous with external skin
Inner 2/3rds within the temporal bone lined with skin continous with the tympanic membrane