Head and Neck 1 Flashcards
Name the individual bones of the skull.
Maxilla Nasal Mandible Zygomatic Frontal Parietal Occipital Temporal Sphenoid
Name the foramen associated witht he skull.
Supraorbital foramen
Infraorbital foramen
Mental foramen
Mandibular foramen (medial aspect of ramus of mandible)
Name the different parts of the mandible.
Body Angle Ramus Condylar process, head and neck Coronoid process
Where do the facial muscles develop from and what innervates them?
Develop from 2nd pharyngeal arch
Innervated by the facial nerve (VII)
What is the name of the muscle surrounding the eye?
Orbicularis oculi
Name the two parts and their functions of the orbicularis oculi muscle.
Orbital part - closes eye tightly
Palpebral part - closes eye lightly
= blinking and distribution of tears
Where is the orbicularis oris found and where does it insert?
Surrounds the oral cavity
Inserts into the mucous membrane of the lips
What is the action of the orbicularis oris?
Compresses and protrudes lips in whistling expression (kissing muscle)
What forms the modiolus?
At the angle of the mouth, the orbicularis oris and fibres from the buccinator form the modiolus
BUCCINATOR AND ORBICULARIS ORIS
Where is the buccinator muscle found?
Muscle of the cheek
What is the origin and attachment of the buccinator muscle?
Origin: posteriorly from the ptyerygomandibular raphe, processes of maxilla and mandible
Insertion: angle of mouth (modiolus)
What is the action of the buccinator?
Presses cheek against molar teeth - aiding chewing
Compresses distended cheeks - expulsion of air from oral cavity (trumpeters muscle)
Pushing food onto grinding surface
What is the frontalis muscle?
Muscle of scalp
Positioned near forehead
Where does the frontalis muscle arise/insert?
Epicranial aponeurosis (galea aponeurotica) - flat tendon Inserts into skin of forehead
What is the action of the frontalis muscle?
Elevates eyebrows and wrinkles forehead
What is the platysma?
Superficial muscle of the neck
Where does the platysma arise from and insert?
Arises from superficial fascia of deltoid and pectoral regions
Inserts into mandible and orbicularis oris
What is the action of the platysma?
Depresses the lower lip
Tenses the skin
What is the action of the zygomaticus major and minor?
Major: pull the angle of the mouth superolaterally (elevate and evert angle)
Minor: pulls upper lip backward, upward and laterally
Describe the position of the parotid gland.
Lies outside the oral cavity
Sternocleidomastoid posterior, ramus of mandible in front, superior is external acoustic meatus and posterior to zygomatic arch
Over masseter muscle
What vessels lie deep to the parotid gland?
External carotid artery
Retromandibular vein
Which nerve lies within the parotid gland?
Facial nerve (VII)
Describe the pathway of the parotid duct.
Leaves anteriorly across masseter muscle, pierces buccinator and enters vestibule of oral cavity opposite 2nd molar tooth
Has thickened fascial capsule
What is the innervation of the platysma muscle?
Cervical branch of facial nerve (VII)
SCALP
Skin
Connective tissue (superficial fascia)
Aponeurosis (connecting frontalis and occipitalis muscles)
Loose connective tissue
Pericranium (outer periosteum of bony skull)
Where do most of the blood vessels and nerves run? (which layer of the scalp? )
Connective tissue layer of the scalp which is dense
Why do scalp lacerations bleed profusely?
Blood vessels are held open by the dense connective tissue layer
Which bone is the mastoid process part of?
Temporal bone
Where is the superficial temporal artery and where does this arise from?
Emerges from the parotid gland anterior to the ear
Originates from the external carotid artery
What is the origin and insertion of the masseter muscle?
Origin - zygomatic arch
Insertion - lateral surface of ramus of mandible
What is the action of the masseter muscle?
Elevation of the mandible
What is the innervation of the masseter?
Masseteric nerve of mandibular nerve (V3)
What is the supply and drainage of the parotid gland?
Branches of ECA
Venous drainage to retromandibular vein
List some clinical issues with the parotid gland.
Parotid gland can have viral infection = mumps Parotiditis = abscesses Calcified deposits (sialogram) - more common in submandibular duct Bell's Palsy = consequence of parotid problems = facial muscle weakness
What are the signs of 7th cranial nerve damage and what urgent care is needed?
Facial muscle paralysis/muscle twitching/weakness
Eye protection - no functioning eyelids/distribution of fluid = dry eye
Where do most arteries of the face come from?
External carotid artery
Where do most veins of the face drain into?
Internal jugular vein
List the medial branch of the ECA.
Ascending pharyngeal
List the 3 front branches of the ECA.
Superior thyroid, lingual, facial
List the 2 branches from behind the ECA.
Occipital, posterior auricular
List the terminal branches of the ECA.
Maxillary and superficial temporal
Which is the smaller of the two terminal branches of ECA?
Superficial temporal
Where does the superficial temporal branch of ECA go and what does it supply?
Emerges on the face between the TMJ and the ear and ascends to temporal region.
Distributes to the skin and facial muscles of the frontal and temporal regions.
Where does the facial artery arise from?
Anterior branch of ECA
Describe the pathway of the facial artery.
Ascends deep to submandibular gland
Winds around the inferior border of the mandible just anterior to the masseter muscle
Tortuous course upwards and medially to medial angle (canthus) of the eye
Where does the facial artery send branches to?
Upper and lower lip and side of the nose
Where does the ophthalmic artery arise from?
Internal carotid artery
Name the terminal branch of the ophthalmic artery.
Supraorbital
Supratrochlear
Where is the facial vein?
Begins at the medial canthus, runs posterior to facial artery
Joins with retromandibular vein and drains into internal jugular vein
Which structures does the facial vein communicate with?
Superior ophthalmic vein at the medial canthus and pterygoid plexus via the deep facial vein
What is the pterygoid plexus?
Network of small veins around the lateral pterygoid muscle
What is important to note about the pterygoid plexus?
No valves in veins = infection can move freely in any direction and end up in the cavernous sinus
Why are pustules of the upper lip dangerous?
In danger triangle of face
Interconnections between veins and lack of valves mean infections of the face can spread intracranially (i.e. into the cavernous sinus)
Facial vs temporal pulse
Temporal pulse: temple region, anterior to ear
Facial: anterolateral angle of masseter muscle against bony surface of mandible
Which nerve and its divisions is responsible for the sensory innervation of the face?
Trigeminal nerve (V)
- Ophthalmic division (V1)
- Maxillary division (V2)
- Mandibular division (V3)
Name the divisions of the ophthalmic division (V1).
Frontal
Lacrimal
Nasociliary
Where does the ophthalmic division enter?
Through the superior orbital fissure
What does the lacrimal nerve supple?
Lateral skin and conjunctiva of the upper eyelid
What is the largest branch of V1?
Frontal
What does the frontal nerve supply?
Upper eyelid, forehead and scalp
What does the frontal nerve give rise to?
Large supraorbital nerve
Small supreatrochlear nerve
What does the nasociliary nerve supply?
Skin of the dorsum of the nose
Where does the maxillary division leave/enter?
Leaves the middle cranial fossa through the foramen rotundum
Enters the pterygopalatine fossa
Name the branches of the maxillary division.
Zygomatic nerve
Posterior superior alveolar nerve
Main nerve = infraorbital nerve
Which nerve of the maxillary division travels through the inferior orbital fissure?
Infraorbital nerve
Where does the infraorbital nerve emerge?
Emerges on the face through the infraorbital foramen.
What does the infraorbital nerve supply?
Lower eyelid, cheek and upper lip
What is important to note about the mandibular division (V3)?
Mixed nerve - (sensory large, motor small)
Where does the mandibular division travel?
Descends through the foramen ovale - gives a nerve to medial pterygoid and then divides into anterior and posterior branches.
List the anterior branches of the mandibular division (all motor except one)
Nerves to lateral pterygoid, temporalis, masseter
Sensory: buccal nerve - cheek skin and vestibular gum
Name the posterior branches of the mandibular division (all sensory except one)
Auriculotemporal, lingual, inferior alveolar nerve
Motor: nerve to mylohyoid
What does the auriculotemporal nerve supple?
Sensory to skin in temporal region
Where does the buccal nerve run?
Anteriorly to supply the cheek
What does the mental nerve supple?
Skin of chin and lower lip
What is the terminal branch of the inferior alveolar nerve?
Mental nerve
Where does the mental nerve arise from?
Mental foramen
Which spinal nerves make up the cranial plexus?
C1-C4
Which spinal nerves make up the great auricular nerve?
C2 and C3
Where does the great auricular nerve go and what does it supply?
Ascends across sternocleidomastoid muscle
Supplies skin over the auricle and angle of the mandible
Where do cutaneous branches from the plexus emerge?
Middle of the posterior border of the sternomastoid
Where is the cervical plexus distributed?
Skin on anterior and lateral side of the neck and lateral side of the head
List the nerves in the cervical plexus.
Greater auricular, lesser occipital, transverse cervical, supraclavicular
What muscles are supplied by the nerves of the cervical plexus?
Strap muscles and small muscles in posterior of neck
What does the phrenic nerve supply sensation to?
Pericardium, pleura and diaphragm
What spinal nerve levels make up the phrenic nerve?
C3, C4, C5
Why do facial lacerations tend to gape widely?
Because the face has no distinct deep fascia and the connective tissue between the facial muscles is loose.
What is the nerve supply of the platysma?
Cervical branch of the facial nerve (VII)
What structures pass through the inferior orbital fissure?
Maxillary artery and nerve
Zygomatic nerve
Which two fossa does the inferior orbital fissure communicate with?
Ptyergopalatine fossa
Infratemporal fossa
The infraorbital nerve is a branch of which nerve?
Maxillary division (V2) of trigeminal nerve
Where does the infraorbital nerve emerge on the face?
Infraorbital foramen
Which nerve gives rise to the supraorbital nerve?
Ophthalmic nerve
What might be signs in the face if the 7th cranial nerve is damaged in its course through the parotid gland?
Facial muscle paralysis of the affected side
Expressive lines in facial skin obliterated and facial distortion
Unable to close eyelids/lips, whistle, blow
Blood and saliva dribbles out of mouth on affected side
What is the most urgent action that needs to be taken for a damaged 7th cranial nerve and why?
Eye protection - eyelids will not be able to move = no protection or distribution of tears, leading to a dry eye.
Infection may set in causing ulceration and fibrosis leading to blindness.
Which cranial nerve does the corneal reflex test?
Trigeminal nerve (V)
The branches of which cranial nerve emerge from the anterior border of the parotid gland?
Facial nerve (VII)
The auricotemporal nerve is a branch of?
The mandibular division of the trigeminal nerve (V)
Describe two sites in the face where arterial pulsation can be felt.
Facial artery - when it winds around the inferior border of the mandible just anterior to the masseter ‘
Superficial temporal artery - compress it against the root of the zygomatic bone
Why are pustules of the upper lip dangerous?
Infection could spread via the facial vein - superior ophthalmic vein into the cavernous sinus.
Where does the facial artery terminate?
Medial angle of the eye
Superficial temporal artery is a branch of?
Terminal branch of ECA
What is the structure directly anterior to the jugular foramen?
Carotid canal
The mastoid process is part of…
The temporal bone
Where does the parotid duct open into?
Oral cavity opposite the crown of the upper second molar
The main sensory nerve to the lower lip is the…
Mental nerve
