Lecture 9- IX- XII Flashcards
CN IX
*
glossopharngheal
where does the glossopharyngeal arise from
the medulla
route of the glossopharngeal
- Arise from medulla
- Run through posterior cranial fossa
- Exit through the jugular foramen
- Enter into carotid sheath- close relationship with internal and external carotid artery
- Glossopharyngeal leaves the sheath early
glossopharygeal is mainly
mainly sensory (oropharynx and tonsils)
where does the glossopharngeal innervate
- Posterior 1/3 tongue (sensory smell and taste)
- General and special sensory taste branches
- 1 swallowing muscle
- Parasympathetic to parotid gland
X
vagus
vagus nerve arises from
medulla
route of the vagus nerve
- Arise from medulla
- Run through posterior cranial fossa
- Exit through the jugular foramen
- Enter into carotid sheath- close relationship with internal and external carotid artery
- Vagus found throughout carotid sheath
- Glossopharngeal and Vagus nerve are
- examined together- because if one has a lesion then the other is lightly to be affected
- Bar some distal branches of the vagus nerve
vagus nerve is both
motor and sensory (more motor)
vagus nerve innervation
- All the muscle of the larynx/pharynx- including soft palate
- Sensory (larynx/laryngopharynx)
- Parasympathetic to many tissues
lesions in Vagus and glossopharngeal
Lesions may present with
- Difficulty with swallow
- Weak cough
- Difficulties with speech or changes in voice
examination of V and G nerve
- Speech
- Swallow
- Cough
- Soft palate movement
- Uvula position (CNX)
- Gag reflex (IX and X)
G and V lesion and soft palate elevation
uvula lies- points to the opposite side of lesion
Causes of lesions in G and V
*
- Recurrent laryngeal branch of vagus (CN X)
- Thyroid pathology or surgery, superior thorax/mediastinal pathology)
- Pathology involving carotid sheath structures
- Posterior cranial fossa, bas eof skull
- Brainstem (medullary) lesions e.g. infact, MMD
key branches of vagus in the enck
CN XI, XII- Accessory and hypoglossal route
- e
*
- Arise from the medulla (accessory nerve also has some contribution from upper cervical spinal nerve)
- Run through posterior cranial fossa
- Accessory nerve- through the jugular foramen
- Hypoglossal- hypoglossal canal
- Enter into carotid sheath
- Hypoglossal exits and travels towards the tongue
- Accessory exits and heads towards posterior triangl
CN XII hypoglossal is purely
motor
target tissue of the hypoglossal
- Tongue movements and protrusion
lesions of the hypoglossal
- Surgery/pathology in proximity to or involving upper carotid sheath, integral and external carotid artery
- Posterior cranial fossa tumours
Hypoglossal and tongue movement
*
- Genioglossus= tongue muscles
- Controlled by right and left CN XII
- Tongue deviates to the weaker half “Lick your wound”
CNXI
spinal accessory
spinal accessory is purely
motor
spinal accessory arises from
medulla (cranial roots and spinal roots)
exam of accessory
- Test actions of SCM (turn head)
- Test action of trapezius (shrug shoulders)
- Lesions of accessory
- Injuries, surgery or pathology involving posterior triangle (or structures within)
- Posterior cranial fossa tumours
- Base of skull (jugular foramen)
- Brainstem (medullary) lesions e.g. infract, Motor Neurone Disease
accessory nerve injury
- Wasting of the muscle
- E.g. shape of shoulder changes
- Weakness in scapula muscle
