Sensory and Motor Supply of the Head Flashcards
What are the 12 cranial nerves?
- I = olfactory
- II = optic
- III = oculomotor
- IV = trochlear
- V = trigeminal
- VI = abducens
- VII = facial
- VIII = vestibulocochlear
- IX = glossopharyngeal
- X = vagus
- XI = accessory
- XII = hypoglossal
Describe if each cranial nerve is sensory, motor or both and also if they are afferent, efferent or both
- I = sensory, afferent
- II = sensory, afferent
- III = motor, efferent
- IV = motor, efferent
- V = both, both
- VI = motor, efferent
- VII = both, both
- VIII = sensory, afferent
- IX = both, both
- X = both, both
- XI = motor, efferent
- XII = motor, efferent
Describe the pathway of the trigeminal nerve
first branchial branch given off from the lateral side of the pons then passes to the middle cranial fossa, where it gives off 3 main branches
What are the 3 main branches of the trigeminal nerve?
- ophthalmic (V1)
- maxillary (V2)
- mandibular (V3)
What does the trigeminal nerve supply sensory function to?
everything in front of the vertex-ear-chin line
What is the only motor supply of the trigeminal nerve?
innervation of the muscles of mastication
Describe the pathway of the ophthalmic division of the trigeminal nerve
runs in the lateral wall of the the cavernous sinus then enters the orbit through the superior orbital fissure
What does the ophthalmic division supply sensory function to?
- skin of the face above the eye
- eyeball
- external nose
What part of the corneal reflex does the ophthalmic division mediate?
the afferent limb by the nasociliary branch
What does the maxillary division of the trigeminal nerve supply sensory function to?
- part of the face below the eyes
- upper lip
- palate
- paranasal sinuses
- upper teeth
Describe the pathway of the maxillary division of the trigeminal nerve
it passes along the lateral wall of the cavernous sinus then exits through the foramen rotundum to the pterygopalatine fossa
What does the mandibular division of the trigeminal nerve supply sensory function to?
- lower part of the face including lower lip, anterior ear and chin
- lower teeth
- anterior 2/3 of the tongue
What does the mandibular division supply motor function to?
- muscles of mastication for biting and clenching of the jaw
- afferent and efferent limbs of the jaw jerk reflex
What does lesion of the trigeminal nerve lead to?
- sensory loss of the face
- weakness of the muscles of mastication
What does lesion of the lingual nerve lead to?
- loss of general sensation and taste to the anterior 2/3 of the tongue
- salivary secretion from the submandibular and sublingual glands
What is trigeminal neuralgia marked by?
shock-like pain along the course of the trigeminal nerve, especially radiating to the maxillary or mandibular area
What are common causes of trigeminal neuralgia?
aberrant blood vessels or aneurysms compressing on the trigeminal nerve at the base of the brain
Describe the pathway of the facial nerve
second branchial branch that leaves the pons at the pontomedullary junction then enters the internal acoustic meatus together with the vestibulocochlear nerve VIII
What is the internal acoustic meatus?
the facial canal in the temporal bone