Topic 8 Cranial nerves Flashcards
Is the Trigeminal root made of sensory or motor fibres?
BOTH
V1 - Sensory upper face
V2 - Sensory to Maxillary area
V3 - Sensory to Mandibular area AND
Motor to TMJ muscles, TVP, TT
Describe the path of the Trigeminal nerve from the brain.
- The V nerve emerges from the pons
- Travels to Trigeminal ganglion (cell bodies)
- Splits into 3 branches before leaving skull
- V1 - Superior orbital fissure
- V2 - Foramen rotundum
- V3 - Foramen ovale
- All 3 branches supply sensory fibres to face, V3 also supplies motor fibres to
- TMJ muscles (temporalis, masseter, LM Ptery.)
- Tensor veli palatini
- Tensor tympani
- Anterior belly of digastric
What would not be a consequence of damage to the largest root of the Trigeminal nerve?
A. Loss of sensation across the forehead
B. Difficulty chewing
C. Inability to feel pressure in the frontal sinus
D. Inability to detect an itch nose
B. Difficulty chewing
The largest root of the Trigeminal ganglion has the cell bodies from the SENSORY neurons. The smaller root has the cell bodies from the MOTOR neurons.
Paralysis of the jaw would be most likely due to damage to which cranial nerve?
Mandibular branch of Trigeminal nerve (CNV3)
Which nerve gives motor innervation to the tensor veli palatini muscle?
Mandibular branch of Trigeminal nerve (CNV3)
Name two muscles innervated by CNV
- temporalis
- masseter
- lateral pterygoid
- medial pterygoid
- tensor veli palatini
- anterior belly of digastric muscle
- tensor tympani
Which cranial nerve and branch supplies sensory information from the forehead, scalp and some eye tissues?
Opthalmic branch of Trigeminal nerve (CNV3)
What effect would a lesion of the trigeminal nerve (before it split into its branches) have on a patient?
- loss of general sensation to that side of face
- paralysis to that side’s:
- TMJ muscles
- mylohyoid
- ant. belly of digastric
- tensor veli palatini
- tensor tympani
What type of fibres does the Facial nerve carry?
Sensory AND Motor
Which two foramina does the Facial nerve pass through?
The Internal auditory meatus and the Stylomastoid foramen
Paralysis of the depressor anguli oris muscle would likely be cause be damage to which nerve?
- Paralysis is the loss of motor innervation. The muscles of facial expression get motor information from the Facial nerve.
- The depressor anguli oris is located below the lip.
- This area is innervated by the marginal mandibular branch of the Facial nerve (CNVII).
- Therefore paralysis of this muscle would result from damage to this nerve.
Name two muscles innervated by the Facial nerve.
-
Muscles of facial expression:
- orbicularis oris
- risorius
- buccinator
- levator labii superioris
- zygomatic major
- zygomatic minor
- levator labii superioris alaeque nasi
- depressor labii inferioris
- depressor anguli oris
- mentalis
- platysma
- posterior belly of digastric muscle
- stylohyoid muscle
- stapedius muscle
Which of the bellies of the digastric muscle is innervated by the Trigeminal nerve? What is the other belly innervated by?
Anterior belly - Trigeminal
Posterior belly - Facial
Which muscles of facial expression of innervated by the buccal branch of the facial nerve?
- lavator labii superioris
- levator labii superioris alaeque nasi
- zygomatic major and minor
- risorius
- buccinator muscle
- orbicularis oris
Which muscles of facial expression are innervated by the marginal mandibular branch of the facial nerve?
- depressor labii inferioris
- depressor anguli oris
- mentalis
Describe the basic structure, function and pathway of the vestibulocochlear nerve (CNVIII).
- From the cochlear, nerve dendrites travel to cell bodies in the cochlear ganglion. The axons from these cell bodies form the cochlear nerve.
- From the semicircular canals and vestibule, nerve dendrites travel to the vestibular ganglion. The axons from thes cell bodies from the vestibular nerve.
- At the internal auditory meatus, these two nerve join to form the vestibulocochlear nerve which carries information about equilibrium (balance) and hearing to the brain via the brainstem.
