Head: Face, Facial Nerve, Trigeminal Nerve Flashcards
Face
- Supraorbital margin to chin, ear-to-ear
- Role in communication and identity
Scalp
- Supraorbital margin to superior nuchal lines, zygomatic arch to zygomatic arch
- Good vascular supply
- 5 layers
5 Layers of the Scalp
- Skin
- Connective tissue (dense)
- Aponeurosis (epicranial aponeurosis)
- Loose connective tissue
- Pericranium
Skin of the scalp contains
- Sweat glands
- Sebaceous glands
- Hair follicles
Aponeurosis of the scalp
- Also called the galea aponeurotica
- Tendon sheet that connects bellies of occipitofrontalis (epicranius)
Loose connective tissue of the scalp
- Potential space, allows for movement of the scalp proper (layers 1-3)
- Danger space of the scalp
Danger space of the scalp
- Emissary veins communicate with the dural sinuses in the cranial cavity
- Infection can spread to cranial cavity structures (meninges)
Pericranium
- Periosteum of the skull
Muscles of facial expression are located/innervated
- Located in the subcutaneous tissue of the face, neck, scalp
- Innervated by facial nerve (CN VII)
- Muscle fibers intermingle
Occipitofrontalis function
- Wrinkles eyebrows
Orcibularis Oculi function
- Narrows palpebral fissure (closes eyelid)
- Assist movement of lacrimal fluid
- Palpebral and orbital parts
Orbicularis Oris function
- Important in speech, eating, facial expression
Buccinator attachments
- Alveolar processes of maxillae and mandible
- Pterygomandibular raphe
Buccinator muscle
- Covered by buccal fat pad
- Helps keep food between teeth during eating
Preganglionics originate in the brainstem and travel in these nerves
- Occulomotor nerve
- Facial nerve
- Glossopharyngeal nerve
- Vagus nerve
Preganglionics of occulomotor nerve pathway
- Occulomotor nerve
- Ciliary ganglia
- Intrinsic eye muscles
Preganglionics of Facial Nerve contains both
- Pterygopalatine ganglia
- Submandibular ganglia
Pteryopalatine ganglia of facial nerve pathway
- Facial nerve
- Pteryopalatine ganglia
- Lacrimal and nasal glands
Submandibular ganglia of facial nerve pathway
- Facial nerve
- Submandibular ganglia
- Sublingual and submandibular glands
Preganglionics of glossopharyngeal nerve pathway
- Glossopharyngeal nerve
- Otic ganglia
- Parotid gland
Preganglionics of vagus nerve pathway
- Vagus nerve
2. Parasympathetic function to thorax/abdomen
Facial Nerve (CN VII) contains
- Somatic motor nerve fibers
- Parasympathetic motor nerve fibers
- Sensory nerve fibers
Two roots of facial nerve exit the brainstem at
- Pontomedullary junction
Two roots of facial nerve exiting through pontomedullary juntcion
- Sensory/parasympathetic root (nervus intermedius)
- Motor root
Sensory nerve fibers of facial nerve root supply
- Somatosensory (part of the ear)
- Taste (anterior 2/3 of tongue and palate)
Presynaptic parasympathetic nerve fibers of facial nerve root supply
- Lacrimal gland
- Submandibular gland
- Sublingual gland
Motor root of facial nerve roots supply
- Muscles of facial expression
- Stapedius
- Stylohyoid
- Posterior belly of digastric
Two roots of facial nerve entry point
- Internal acoustic meatus
- Join together inside the facial canal
Branches of facial nerve in the facial canal
- Greater petrosal nerve
- Chorda tympani nerve
- Nerve to stapedius
Greater Petrosal Nerve contains
- Preganglionic parasympathetic fibers
- Go to pterygopalatine ganglion (located in the pterygopalatine fossa)
Chorda Tympani Nerve
- Preganglionic parasympathetic fibers to the submandibular ganglion
- Taste from anterior 2/3 of tongue
Nerve to Stapedius
- Innervates stapedius muscle
Geniculate Ganglion contains
- Cell bodies of sensory neurons associated with CN VII (somatosensory, taste)
Motor to facial muscles exit point
- Exits skull through stylomastoid foramen
Motor to facial muscles gives off
- Posterior auricular branch
- Branches to stylohyloid and posterior belly of digastric
Entry point of motor innervation
- Enters parotid gland
- Forms parotid plexus (within gland)
Branches of the Parotid Plexus
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
Lesions to Facial Nerve
- Symptoms depend on location of injury
- Paralysis of facial muscles
- Hyperacusis
- Loss of corneal reflex
Loss of/altered functions/sensations in lesions to the Facial Nerve
- Lacrimation
- Taste anterior 2/3 tongue
- Salivation
Bell’s Palsy
- Idiopathic facial paralysis
- Cause: unknown exactly
- Compression, ischemia, demyelination of facial nerve in facial canal
- Can see other symptoms depending on location
Content of the Parotid region
- Parotid gland and duct
- Facial nerve (parotid plexus)
- Retromandibular vein
- External carotid artery
- Parotid lymph nodes
- Masseter muscle
Parotid region content that passes through the glandular tissue
- Facial nerve (parotid plexus)
- Retromandibular vein
- External carotid artery
Parotid Gland
- Largest salivary gland
- Facial nerve plexus embedded within
- Surrounded by parotid sheath (connective tissue capsule)
- Inflammation is painful
Parotid Gland location
- Between mandibular ramus and mastoid process
Parotid duct (Stensons duct)
- 5-7 cm long
- Finger width below zygomatic arch (superficial location)
- Crosses masseter and dives deep at its anterior border
- Pierces buccal fat pad and buccinator to enter oral cavity (2nd maxillary molar)
- Buccal branches of facial found alongside
Sensory innervation of the Parotid Gland
- Auriculotemporal nerve (branch of V3)
- Great auricular nerve
Autonomic innervation of Parotid Gland influences
- Glandular secretion
- Blood flow to the gland
Sympathetic innervation of the Parotid Gland
- Postsynaptic from superior cervical ganglia
- Travel in the the external carotid nerve plexus to the gland
Parasympathetic innervation of the Parotid Gland
- Presynaptic travel in glossopharyngeal nerve (CN IX)
Cutaneous innervation of the face and scalp
- Trigeminal nerve
- Dorsal rami of C2 and C3
- Lesser occipital
- Great auricular
Trigeminal nerve innervates
- Face and scalp anterior to the vertex
Dorsal rami of C2 and C3 innervate
- Posterior to vertex
- Upper neck
Lesser occipital nerve innervation
- Cervical plexus
- C2
Great auricular nerve innervation
- Cervical plexus
- C2 and 3
Trigeminal nerve roots (motor and sensory) emerge from
- The pons
Three divisions of Trigeminal Nerve
- Ophthalmic (V1)
- Maxillary (V2)
- Mandibular (V3)
Sensory root of Trigeminal Nerve (follows all 3 divisions)
- Face, oral cavity, tongue, palate, nasal cavity, sinuses
- Sensory cell bodies are located in the trigeminal ganglion
Motor root of Trigeminal Nerve (follows V3) innervates
- Muscles of mastication
- Tensor tympani
- Tensor veli palatini
- Anterior belly of digastric and mylohyoid
Opthalmic Nerve (V1) passes through
- Passes through superior orbital fissure to enter orbit
- Branches associated with face sensation
Frontal branches of Opthalmic Nerve (V1)
- Supraorbital
- Supratrochlear
Nasociliary branches of Opthalmic Nerve (V1)
- External nasal
- Infratrochlear
Branches of Opthalmic Nerve (V1) associated with facial sensation
- Fronatl
- Nasociliary
- Lacrimal
Maxilarry Nerve (V2) passes through
- Passes through foramen rotundum to enter pterygopalatine fossa
- Branches associated with face sensation
Branches of Maxillary Nerve (V2) associated with facial sensation
- Zygomatic
- Infraorbital
Zygomatic branches of Maxillary Nerve (V2)
- Zygomaticotemporal
- Zygomaticofacial
Mandibular Nerve (V3) passes through
- Passes through foramen ovale to enter infratemporal fossa
- Branches associated with facial sensation
Branches of Mandibular Nerve (V3) associated with facial sensation
- Auriculotemporal
- Buccal
- Mental nerve
Arteries of face and scalp are primarily branches of
- External carotid
Branches of external carotid that supply the face and scalp
- Occipital
- Posterior auricular
- Superficial temporal
Superficial Temporal branch of ECA
- Terminal branch of external carotid
- Passes between TMJ and auricle
- Travels with auriculotemporal nerve
Branches from opthlamic artery (which is a branch of the internal carotid) that supply the face and scalp
- Supraorbital
- Supratrochlear
Arteries of the face
- Transverse facial artery
- Branch of superficial temporal
- Mental artery
- Supraorbital and supratrochlear arteries (from the internal carotid)
Facial artery branches
- Inferior and superior labial arteries
- Lateral nasal
- Angular: terminal continuation of facial
Veins of the scalp (same names as the arteries)
- Supraorbital vein
- Supratrochlear vein
- Superficial temporal vein
- Occipital vein
- Posterior auricular vein
Veins of the face
- Supraorbital
- Supratrochlear
- Angular vein
- Facial vein
- Retromandibular vein
Angular vein
- Communicates through orbit with superior ophthalmic vein
- Route of infection spread from face to intracranium
Facial vein
- Continuation of angular vein
Retromandibular vein is formed by/passes through
- Superficial temporal and maxillary veins
- Passes through parotid gland superficial to ECA
Posterior division of retromandibular vein
- Joins posterior auricular > EJV
Anterior division of retromandibular vein
- Joins facial > common facial > IJV
Supraorbital and supratrochlear veins
- Unite to form the angular vein
Facial pulse location
- Anterior to masseter muscle
Superficial temporal pulse location
- Anterior auricle
Lymph drainage of the superficial face and scalp
- Drain into pericervical collar of lymph nodes
Submental node receive drainage from
- Chin
- Central lip
Submandibular nodes receive drainage from
- Lateral nose
- Upper lip
- Lateral lower lip
Parotid nodes receive drainage from
- Lateral face
- Ffrontal/temporal scalp
- Eyelids
- External acoustic meatus
Preauricular nodes receive drainage from
- Lateral parietal scalp
- Anterior ear
Mastoid nodes receive drainage from
- Posterior ear
- Posterolateral scalp
- Posterior external auditory meatus
Occipital nodes receive drainage from
- Posteror scalp (occipital area)
All superficial face and scalp eventually drain into
- Superficial and deep cervical lymph nodes (mostly deep cervical nodes)
Tympanic nerve (branch of CN IX) travels to
- The tympanic plexus
- Exits tympanic cavity in the lesser petrosal nerve
Foramen ovale
- Exit point for tympanic nerve
- Nerve travels along floor of middle cranial fossa, exits out the foramen ovale
After exiting the foramen ovale, the tympanic nerve
- Synapses in the otic ganglion located in infratemporal fossa
Postsynaptic fibers of tympanic nerve
- Travel within the auriculotemporal nerve (branch of V3) to the parotid gland