Clinical Head III Flashcards
Describe the middle ear
Ossicles
• Malleus, incus, and stapes
- Muscles
- Stapedius muscle and tensor tympani
- Nerves
- Facial nerve and chorda tympani.
What are the branches of the facial nerve?
- Intracranial branches
- Greater petrosal nerve
- Nerve to stapedius
- Chorda tympani
- Extracranial branches
- Posterior auricular nerve
- Branch to posterior belly of digastric muscle & the stylohyoid muscle • Five major facial branches (in parotid gland)
What are the effects of the intracranial facial nerve injury?
Injury of the facial nerve in its pathway to the stylomastoid foramen(exit from the skull will result in varying degree of functional loss.
- Facial nerve- total loss of nerve function usually accompanied by CN VIII injury
(Schwannoma) - Facial nerve (facial canal)- total loss of nerve function, no CN VIII symptoms
- Greater petrosal nerve – nasal and paranasal mucosal glands, lacrimal gland affected
- Facial nerve (medial wall of middle ear) - affects special sensory taste anterior 2/3 of the tongue, submandibular and sublingual salivary glands, muscles innervated by the facial nerve.
- Chorda tympani- special sensory taste anterior 2/3 of the tongue,
submandibular and sublingual salivary glands (middle ear surgery)
What happens when when the hypoglossal nerve is paralyzed?
Paralysis of this nerve makes half of the tongue immobile and eventually will atrophy.
• Test by asking the patient to stick out the tongue; it will deviate towards the affected side due to the unopposed action of the unaffected half of the tongue
Where does the hypoglossal nerve pass?
The hypoglossal nerve passes downwards/inferiorly between the internal jugular vein and the internal carotid artery, until it is crossed laterally by the occipital artery.
▪ The nerve then swings forwards crossing (laterally) both carotid arteries and loops anteriorly at the commencement of the lingual artery
▪ It supplies all the muscles of the tongue except palatoglossus.
What is jugular Foramen syndrome?
Unilateral paresis of cranial nerves IX, X, and XI ( with or without XII) resulting from lesions in the area of the jugular foramen.
What are the symptoms of the jugular Foramen syndrome?
Dysphonia/hoarseness • Soft palate dropping • Deviation of the uvula towards the normal side • Loss of sensory function from the posterior 1/3 of the tongue
• Decrease in the parotid gland secretion
• Lossofgagreflex
• Sternocleidomastoidand
trapezius muscles paresis • Dysphagia
What are the causes of the jugular Foramen syndrome?
Primary tumors: 1. Glomus jugular tumors (most frequently) 2. Meningioma 3. Vestibular Schwannoma 4. Cerebellopontine angle metastases • Inflammation • Internal jugular vein thrombosis
What is a cough?
A protective reflex, which helps to clear the large breathing passages from fluids, irritants, foreign particles and microbes.
• The cough reflex consists of three phases:
- An inhalation
- A forced exhalation against a closed glottis
- A violent release of air from the lungs following opening of the glottis
What’s the gag refk3x?
The pharyngeal reflex or gag reflex (also known as a laryngeal spasm?) is a reflex contraction of the back of the throat.
- The gag reflex:
- The sensory limb is mediated predominantly by CN IX (glossopharyngeal nerve) • The motor limb by CN X (vagus nerve).
What does the glossopharyngeal nerve innervate?
SE- stylopharyngeus
SA
- posterior 1/3 if tongue, tonsils, tympanic membrane, superior pharynx
- afferent limb of gag reflex
- pseudounipolar neuronal cell bodies in superior ganglion of IX
VE(synapse oncotic ganglion)
-parasympathetic innervation of the parotid gland
VA
- carotid body and carotid sinus
- taste from the posterior 1/3 of the tongue
- pseudounipolar neuronal cell bodies in inferior ganglion of IX
What are the unique parts of the glossopharyngeal?
The motor part of the glossopharyngeal nerve supplies only one muscle, the stylopharyngeus.
- Taste sensation on the posterior part of the tongue could theoretically be tested.
- The gag reflex tests both glossopharyngeal (afferent limb) and vagal (efferent limb) function.
What are LeFort (maxillary)fractures ?
- Severe soft tissue swelling, ecchymosis, airway obstruction
- All need maxillofacial consult
- Dispo:
- Likely admission, IV ab, surgical management
- Some may be d/c’d home
What are the signs of ale Fort Nasomaxillary signs?
Malocclusion Buccaneers eccymosis Epitaxis Maxillary crepitus Maxilla mobile
What are the signs of Le Fort: Pyramidal?
Signs: Midface crepitus Facial lengthening Bilateral epitaxis Infraprbital parasthesia Ecchymosis (buccaneers, periorbital, subconjunctival)
