Lecture 5 (head pt 2) Flashcards
What are the 2 nerves of the face? Describe them
1) CN VII: facial nerve, mostly motor (for facial expression)
2) CN V: trigeminal nerve, mostly sensory, has three named branches called V1-2-3
1) What 2 areas does CNVII innervate?
2) What does it travel? Why is this unique?
3) Where does it exit the face?
4) Where is it located?
1) Internal acoustic meatus and muscles of facial expression
2) Goes through facial canal, which is the longest boney canal any nerve must traverse, so it’s at risk
3) Styloid mastoid foramen
4) Deep to parotid gland
1) What nerve innervates the top half of the head?
2) What does it transmit?
1) CNV (has 3 branches, V1-3. )
2) Just somatic sensory
What does CNI do?
Doesn’t really do much to skin, just to muscles in suboccipital triangle
What nerve allows for facial expression?
CNVII (7)
What are the 6 muscles of facial expression? What are they all innervated by?
1) Occipitofrontalis (assoc. w frontal belly and epicranial aponeurosis)
2) Occipital belly
3) Orbicularis oculi (orbital sphincter)
4) Orbicularis oris (oral sphincter)
5) Buccinator (cheek muscle)
6) Platysma
All innervated by CNVII
List what’s embedded in the parotid gland from superficial to deep
1) Parotid plexus of facial nerve
2) CN VII
3) Retromandibular vein
4) External carotid artery + lymph nodes
What is CNV?
Cranial Nerve V, Trigeminal nerve
What are the 3 parts of CNV?
1) V1 - ophthalmic (cornea, nose, forehead)
2) V2 - maxillary (cheeks, tiny piece of nose and top of teeth)
3) V3 - mandibular (mandible, some temporal)
What are the afferent and efferent components of the corneal touch reflex?
Afferent component is V1, motor component is CVII
What are the afferent and efferent components of the light reflex?
Optic nerve is afferent, constriction would be CNIII’s sympathetic division
Where does each part of the trigeminal nerve exit?
V1: supraorbital foramen or notch
V2: infraorbital foramen
V3: mental foramen via mandibular canal
1) What do the lateral pterygoid muscles do? Where is it?
2) What about the medial pterygoids?
3) What are they innervated by?
1) Lateral pterygoid m. open mouth (gravity prime mover), protrudes chin
-goes from TMJ across zygomatic arch
2) Medial pterygoid m. closes mouth, protrusion
-goes from lateral part of angle of mandible to medial part of lateral pterygoid muscle
3) Innervated by anterior trunk mandibular n., CN V3
When contracted unilaterally, the lateral and medial pterygoid muscles do what?
Cause a lateral chewing motion, grinding motion
What is TMJ [pain] often mistaken as? Why?
Ear pain, because that joint is so close to the external auditory canal
1) What is TMJ?
2) How does it often manifest?
3) What are TMDs?
1) Temporal Mandibular Joint syndrome (TMJ)
2) As “earache” in teens and adults
3) Temporomandibular disorders: a heterogeneous group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint complex, and surrounding musculature and osseous components.
1) What percent of the population is affected by TMDs? When is peak incidence?
2) What are the two classifications of TMDs?
3) What are common symptoms of TMDs?
1) TMD affects up to 15% of adults, with a peak incidence at 20 to 40 years of age.
2) TMD is classified as intra-articular or extraarticular.
3) Jaw pain or dysfunction, earache, headache, and facial pain.
1) What is the etiology of TMDs?
2) How are TMDs diagnosed?
3) When may diagnostic imaging be beneficial?
1) Multifactorial; includes biologic, environmental, social, emotional, and cognitive triggers.
2) Diagnosis most often based on history and physical examination.
3) When malocclusion or intra-articular abnormalities are suspected.
1) How are TMDs improved in most cases?
2) What medications are recommended initially, and what medications are recommended for chronic cases?
3) What is recommended for refractory cases?
1) Most pts improve with a combination of: noninvasive therapies, including patient education, self-care, cognitive behavior therapy, pharmacotherapy, physical therapy, and occlusal devices.
2) Nonsteroidal anti-inflammatory drugs and muscle relaxants are recommended initially, and benzodiazepines or antidepressants may be added for chronic cases.
3) Referral to an oral and maxillofacial surgeon is indicated for refractory cases.
1) What are most arteries to the face branches of?
2) What are most external facial veins drained by?
3) Does this vary? If so, what are the alternate routes?
1) External carotid a.
2) Veins that accompany the arteries
3) Varies; alternate route include superficial and deep drainage
1) Where does the facial artery arise from?
2) What does it supply?
3) Can you palpate its pulse?
1) External carotid a.
2) It’s the major artery to superficial face
3) Yes
List the 5 branches of the external carotid artery that supply the face
1) Lingual a.
2) Facial a.
3) Occipital a.
4) Posterior auricular a.
5) Maxillary a
What two arteries that supply the face don’t originate from the external carotid? Where do they come from?
Supratrochlear and supra-orbital arteries are from internal carotid branches
1) What does the superficial temporal artery arise from?
2) What is one of its characteristics?
1) External carotid a.
2) Can palpate its pulse
What two arteries of the face can you palpate the pulses of?
Facial arteries and temporal arteries
1) What is an inflamed temporal artery called? (2 names)
2) What causes it?
3) What are its symptoms?
1) Temporal arteritis (Giant Cell Arteritis)
2) The cause of the blood vessel inflammation is unknown; maybe autoimmune?
3) Headaches, jaw pain, vision loss, fever, and fatigue
1) What is Temporal arteritis (Giant Cell Arteritis) associated with?
2) How is it diagnosed?
3) Is this an urgent condition? Why or why not? How is it treated?
1) Associated with PMR (polymyalgia rheumatica)
2) Usually requires biopsy of the temporal a.
3) Needs prompt treatment with steroid medications to prevent potential CRA (central retinal artery) occlusion & vision loss.
1) What 3 arteries arise from the external carotid artery?
2) What 2 arteries arise from the internal carotid artery?
1) External: Occipital, posterior auricular, and superficial temporal arteries
2) Internal: Supratrochlear and supra-orbital arteries
Do arteries of scalp and face anastomose?
Yes, they anastomose freely with each other
1) What is the primary vein that drains the face?
2) Do facial veins drain anastomosis? Elaborate.
3) What vein drains the cranial sinuses?
1) Facial vein
2) Variable, frequent anastomosis between internal/external jugular vv.
3) Internal jugular vein
1) What area doesn’t have lymph nodes? What is the exception?
2) Where does lymph drain into? Name each place and where they’re located.
1) No lymph nodes in scalp or face except for parotid/buccal region
2) Lymph drains into superficial cervical ring of nodes, which are: Submental, submandibular, parotid, mastoid and occipital nodes
-Located at junction of head and neck; deep cervical along the IJV
What conditions are associated with cervical lymph nodes?
1) Streptococcal pharyngitis (GABHS): cervical adenopathy
2) Mononucleosis (EBV): cervical adenopathy
3) Lymphomas
Name 2 features of the temporal region and describe their locations
1) Temporal fossa: Superior to zygomatic arch
2) Infratemporal fossa: Inferior/deep to zygomatic arch
Describe the location of the infratemporal fossa
-Deep and inferior to zygomatic arch
-Deep to ramus of mandible
-Posterior to maxilla
What are the contents of the infratemporal fossa?
-Maxillary goes behind it (so the MMA is at risk).
-Mastication muscles: Lateral & medial pterygoid muscles
-Inferior part of temporalis m.
-Pterygoid venous plexus
-CN V2, Maxillary n. (provides parasympathetic motor innervation for glands and stuff)
What is at risk if the infratemporal fossa is damaged?
Maxillary artery, MMA (middle meningeal artery), otic ganglia,
What are the 3 parts of the maxillary artery?
*not super important
1) Mandibular part (Middle meningeal a.)
2) Pterygoid part
3) Pterygopalatine part
What nerve(s) and branches course through the foramen ovale? Where do they then go?
CNV V3 (mandibular nerve) courses through F. ovale into infratemporal fossa
What is the sensory & Motor root of CNV?
V3 (mandibular nerve)
What are the 2 parts of V3 (mandibular n)?
Posterior and anterior
1) What branches off the posterior part of the mandibular nerve?
2) What about the anterior part?
1) Posterior trunk: Auriculotemporal n., inferior alveolar n, lingual n.
2) Anterior trunk: Buccal n. and 4 muscles of mastication (masseter, temporalis, & pterygoids)
What are the 4 muscles of mastication?
1) Temporalis
2) Masseter
3&4) Medial and lateral pterygoid m.
What is the one muscle of mastication that’s not supplied by the anterior trunk of the mandibular nerve/ V3?
Buccinator; supplied by CN VII (facial nerve)
What supplies the 4 muscles of mastication?
The anterior trunk of the mandibular nerve (V3)
Slide 39
1) What artery does CNIII follow? What do they do?
2) What type of innervation controls the constriction muscles of the eye? What else does it do?
3) What does the sympathetic part of CNIII control?
1) Internal carotid and CNIII run together; helps with eye dilation
2) Parasympathetic does constriction muscles of iris and interacts w ciliary body
3) Sympathetic only works on the iris (not ciliary body)
List all of the 6 clinical implications to injury to the infratemporal region
1) Disruption of zygomatic arch, TMJ, mandible
2) Blood loss to region to include teeth, meninges, etc.
3) V3 somatic motor (muscles of mastication)
4) Parasympathetic via Submandibular ganglia to lingual n. to SM and SL salivary glands
5) Special sensory (taste anterior 2/3 of tongue via chordae tympani branch of CN VII)
6) Parasympathetic via Otic ganglion to parotid gland
What does the oral cavity and oral pharynx contain?
Tongue (muscles) covered in mucus membrane
What does the tongue muscles (covered in mucous membrane) do?
1) Mastication
2) Taste
3) Deglutition
4) Speech articulation
5) Oral cleansing
What two parts of the tongue are mobile?
Body and apex
What are the 2 categories of muscles that control the tongue? Describe each
1) 4 Extrinsic muscles alter position: Originate from bony formations outside the tongue (more anchored to floor)
2) 4 Intrinsic muscles alter shape: Confined to tongue
What runs through the mandible?
Trigeminal nerve and blood vessels
What control the gag reflex? (afferent and efferent)
1) Afferent (sensory): Glossopharyngeal n. (CN 9)
2) Efferent (motor): Vagus n. (CN10)
What are all muscles of the tongue controlled by?
Hypoglossal (CNXII)
1) What allows you to generally sense with the anterior 2/3rds of your tongue? (also name specific branch)
2) What allows you to taste with the front of your tongue? (also name specific branch)
1) General sensation = CN V3; lingual n.
2) Taste = CN VII; tympani nerve
What allows you to sense with the posterior 1/3 of the tongue?
1) General and special sensory = CN IX
2) Minor contribution from CN X
1) What do you taste at the tip of your tongue?
2) What about the lateral margins?
3) What about the posterior part?
4) What are all other tastes?
1) Sweet at tip
2) Saltiness lateral margins
3) Sour and bitter posterior
4) All other “tastes” are olfactory
Describe the vascular supply of the tongue (2 main arteries, one w 3 branches)
1) External carotid
2) Lingual artery
-Dorsal lingual a.
-Deep lingual a.
-Sublingual a.
1) What veins drain the tongue?
2) Where do these veins drain?
1) Dorsal & Deep lingual veins
2) Venous drainage into IJV
1) Does the tongue’s lymphatics drain bilaterally or unilaterally?
2) What are the lymph nodes of the tongue?
1) Posteriorly and midline area drain bilaterally
2) Lateral and front drain to mental and submandibular nodes; posterior drains to cervical nodes
What are the 3 salivary glands? Describe their ducts
1) Parotids: has one duct from each gland, esp. affected by mumps
2) Submandibular: has one duct from each gland
3) Sublingual: has multiple ducts
Where is the submandibular duct?
Opens onto sublingual papilla opposite of 2nd molar
1) Where are the sublingual glands?
2) Where do they unite and where do the ducts open?
3) What is their innervation?
1) Lie between mandible and genioglossus muscles.
2) Unit anteriorly; ducts open on floor of the mouth
3) Same innervation as submandibular glands (CN VII parasympathetic)
1) Define refractory [in terms of illnesses]
2) Define heterogenous group of disorders
1) Illnesses that don’t respond to treatment
2) A group of disorders with different causes (think opposite of homogenous)
Where are the stylomastoid foramen?
Lateral and slightly anterior to the foramen magnum
What innervates the cutaneous part of the back of the head?
Spinal nerves
