Face Flashcards
Briefly describe blood supply/drainage to face
External carotid branches to facial artery
Facial artery can be palated at inferior border of mandible
(Internal carotid supplies the brain…not face!)
- Facial vein drains into internal jugular vein to subclavian vein
- Superficial temporal vein and maxillary vein drain into external jugular and then to subclavian vein
Briefly discuss the nervous control of the muscles of the head
CN VII : muscles of facial expression CN VII : cheek muscles (buccinators) CN VII : occipitofrontalis muscle CN V3 : muscles of mastication CN VII : platysma (Deirdre neck! - grimacing depresses mandible)
Briefly describe the fascia of the face
Broadly divided into superficial and deep cervical fascia
Superficial cervical fascia: subcutaneous tissue between dermis and investing deep fascia (houses platysma)
- cleavage planes allow easy movement
- fascia layers glide over each other
Deep cervical fascia: subdivided into four separate layers
- Investing fascia: most superficial enclosing sternocleidomastoid and trapezius
- Pretracheal fascia: surrounds trachea, oesophagus and thyroid. It blends with carotid sheaths (laterally) and pericardium (posteriorly)
- Prevertebral fascia: surrounds vertebral column and associated muscles, from base of cranium to T2/3
- Surrounds common carotid artery, internal jugular and CN X, from base of cranium to root of neck
What potential spaces exist between the fascia and why are they important?
Retropharyngeal space: between para vertebral and pharynx fascia running to diaphragm
Para pharyngeal space: lies laterally but doesn’t descend as deep as retro pharyngeal space (can be affected by dental/tonsil issues)
Can allow infections to track from head/neck to other parts of the body
Infections between investing and Pretracheal can track to manubrium
Infections between investing and visceral Pretracheal can extend into thorax
What are the borders of the anterior triangle in the neck?
Anterior: midline Posterior: sternocleidomastoid Superior: mandible Apex: jugular notch (manubrium) Roof: superficial fascia (platysma) Floor: pharynx, larynx, thyroid
How is the anterior triangle subdivided and what are the contents of the divisions?
Submandibular triangle
- submandibular gland, lymph nodes, hypoglossal and myeloid nerves, facial artery and vein
Submental triangle
- lymph nodes, veins leading to anterior jugular vein
Carotid triangle
- carotid sheath, thyroid, larynx, pharynx, external carotid, hypoglossal and spinal accessory nerves and cranial plexus branches
Muscular triangle
- sternothyroid, sternohyoid, thyroid, parathyroid
What are the borders of the posterior triangle of the neck?
Anterior: sternocleidomastoid
Posterior: trapezius
Inferior: middle third of the clavicle
Apex: meeting of sternocleidomastoid and trapezius
Roof: investing deep fascia
Floor: muscles within the prevertebral fascia
How is the posterior triangle subdivided and what are the components of each?
Occipital triangle
- spinal accessory nerve, brachial plexus trunks, external jugular vein, posterior branch of cervical plexus, cervicodorsal trunk and cervical lymph nodes
Omoclavicular triangle
- third part of subclavian artery and vein, supra scapular artery and supra clavicular lymph nodes
Discuss the hyoid muscles
Hyoid is a floating bone at C3 level
Supra hyoid muscles: elevate hyoid/larynx during swallowing and provi a base for tongue functions
- DGeMS
- digastric (mastoid tip to mandible), geniohyoid, mylohyoid, and stylohyoid
Infra hyoid muscles: depress hyoid/larynx during swallowing/speech
- TOSS
- thyrohyoid, omohyoid, sternohyoid, sternothyroid (sit on top of each other in layers)
Give a brief overview of the cranial nerves
I: sensory: OLFACTORY - sense of smell
II: sensory: OPTIC - visual acuity and optic fields
III: motor: OCCULOMOTOR - extra ocular movements
IV: motor: TROCHLEAR - extra ocular movements
V: both: TRIGEMINAL - facial sensation and muscle of mastication
VI: motor: ABDUCENS - extra ocular movements
VII: both: FACIAL - taste and facial expressions
VIII: sensory: VESTIBULOCOCHLEAR - hearing
IX: both: GLOSSOPHARYNGEAL - sensory gag and swallowing
X: both: VAGUS - motor gag and pharyngeal sensation
XI: motor: SPINAL ACCESSORY - cranial branch to pharynx, spinal branch to trapezius and sternocleidomastoid
XII: motor: HYPOGLOSSAL - tongue movements
Briefly discuss CN I - VI and effects of possible lesions
I: OLFACTORY
- olfactory tract doesn’t leave brain (surrounded by meninges) and reaches nose via cribriform plate. A # of this causes anosmia
II: OPTIC
- # to orbit or damage to nerve pathway can cause loss of pupil constriction and visual field defects
III: OCULOMOTOR
- innervates extra ocular, ciliary and sphincter pupillae muscles
- ocular movements are somatic whilst pupil constriction is autonomic
- lesions can cause dilated pupil,ptosis, eye turns down and out
IV: TROCHLEAR
- innervates superior oblique of eye, so lesions cause eye to be unable to look down she eye is addicted (double vision)
V: TRIGEMINAL
- V1: ophthalmic (superior orbital fissure) sensory to corneal reflex
- V2: maxillary (foramen rotunden) sensory to skin, nasal mucus membrane
- V3: mandubular (formamen ovale) sensory to skin, lower teeth and tongue; motor to mastication muscles
VI: ADBUCENS
- innervates lateral rectus, so eye can’t move sideways if damaged
Discuss CN VII - XII and possible effects of lesions
VII: FACIAL
- sensory (taste: anterior third of tongue) exiting via stylomastoid foramen
- motor to muscles of facial expression
- facial palsy if lesion in parotid region causing loss of tone on affected side (symptoms will not resolve)
- Bell’s palsy, due to infection whereby symptoms can improve
Branches:
- temporal: occipitofrontalis, orbicularis oculomotor
- zygomatic: orbicularis oculi
- buccal: orbicularis oris, buccinator, zygomaticus
- marginal mandibular: mentalis
- cervical: platysma
VIII: VESTIBULOCOCHLEAR
- balance and hearing
IX: GLOSSOPHARYNGEAL
- sensory to taste (posterior third of tongue), carotid body and sinus
- motor to stylopharyngeus (shortens pharynx)
X: VAGUS
- sensory to lower pharynx/larynx, and taste to epiglottis
- motor to muscles of pharynx, airways, heart, GI, larynx and palate muscles
- lesions can affect the recurrent laryngeal nerve (branch of vagus)
XI: SPINAL ACCESSORY
- cranial to pharynx, larynx and soft palate
- spinal (C2-C4) trapezius and sternocleidomastoid
XII: HYPOGLOSSAL
- all tongue muscle except palatoglossus
Discuss sympathetic innervation of the head and neck
SYMPATHETIC TRUNK: thoracolumbar (T1-L2)
- anterolateral to vertebral column on prevertebral fascia and muscles
- deep to carotid sheath
- short preganglionic neurone, long post ganglionic neurone
- travel with internal/external arteries
Three main branches
- Via internal/external carotid arteries to superior cervical ganglion
- to pharyngeal plexus (parotid, sublingual, submandibular and lacrimal glands
- to upper 4 CN (sphincter papillae, ciliary muscle and lacrimal gland)
- to cardiac branch of cardiac plexus - Via inferior thyroid artery to middle cervical ganglion
- to cardiac branch of cardiac plexus
- to CN V and VI - Via vertebral artery to inferior cervical ganglion
- to cardiac branch of cardiac plexus
- to CN VII and VIII
(In 80% people inferior cervical ganglion combined with first thoracic ganglion - stellar ganglion)
Discuss parasympathetic innervation of the head and neck
PARASYMPATHETIC GANGLIA: craniosaccral (CN III, VII, IX, X, S2-4)
- CN III to ciliary ganglion (Edinger-Westphal)
- to sphincter papillae and ciliary muscles
- pass with CN V1 (ophthalmic nerve)
2a. CN VII to pterygopalatine ganglion (via greater petrossal nerve)
- also known as super salivatory ganglion
- to lacrimal, nasal, palate and nasopharyngeal glands
- pass with CN V2 (maxillary nerve)
2b. CN VII to submandibular ganglion (via chorda tympani and lingual nerve)
- also known as superior salivatory ganglion
- to submandibular and sublingual gland
- pass with CN V3 (mandibular nerve)
3a. CN IX to optic ganglion (via auricotemporal nerve)
- also known as inferior salivatory ganglion
- to parotid gland
- pass with CN V3 (mandibular nerve)
3b. CN IX passes directly (or via pharyngeal plexus to glands of oropharynx and posterior third of tongue
4. CN X passes direct to glands of laryngopharynx, larynx, oesophagus and trachea
