Week 6- Cranial Nerves Flashcards
Where does optic nerve arise
retina of the eye
Describe optic nerve
Optic nerve• Arises from the retina of the eye•
Optic nerves pass through the optic canals and converge at the opticchiasm•
continue to the thalamus where they synapse•
, the optic radiation fibers run to the visual cortex•
Functions- sensory- solely by carrying afferent impulses f
Oculomotor nerve function
Raising eyelid
Directing eyeball
PARASYMPATHETIC CONTROL
Constricting iris
Controlling lens shape
Where are oculomotor nerve fibres
Fibers extend from the ventral midbrain, pass through the superior orbitalfissure, and go to the extrinsic eye muscles
Where does trochlear nerve fibres arise
AND FUNVTION
dorsal midbrain and enter the orbits via thesuperior orbital fissures; innervate the superior oblique muscle• Primarily a motor nerve that directs the eyeball
What is trigeminal nerve composed of
Opthalamic
Maxillary
Mandibular
Where do trigeminalk nerve fibres run
the face to the pons via the superior orbital fissure (V1),the foramen rotundum (V2), and the foramen ovale (
Function of trigeminal nerve
V3)• Conveys sensory impulses from various areas of the face (V1) and (V2), andsupplies motor fibers (V3) for mastication
Fibres and function of abducens nerve
• Fibers leave the inferior pons and enter the orbit via the superior orbitalfissure•
Primarily a motor nerve innervating the lateral rectus muscle (abducts theeye; thus the name abducens)
Where are fibres of facial nerve
• Fibers leave the pons, travel through the internal acoustic meatus, andemerge through the stylomastoid foramen to the lateral aspect of theface
Motor and sensory function of facial nerve
• Motor functions include facial expression, and the transmittal ofautonomic impulses to lacrimal and salivary glands•
Sensory function is taste from the anterior two third of tongue
Where do fibres arise from vestibulocochlear nerve
• Fibers arise from the hearing and equilibrium apparatus of the inner ear,pass through the internal acoustic meatus, and enter the brainstem at thepons-medulla border
Name 2 divisions in vestibulocochlear
Cochlear (hrearing)
Vestibular (balance)
Where do fibres of glossopharyngeal nerve arise
emerge from the medulla, leave the skull via the jugularforamen, and run to the throat
Sensory and motor function of glossopharyngeal nerve
• Nerve IX is a mixed nerve with motor and sensory functions•
Motor – innervates part of the tongue and pharynx, and providesmotor fibers to the parotid salivary gland•
Sensory – fibers conduct taste and general sensory impulses from thetongue and pharynx
What is the only nerve that extends beyond head and neck
Vagus nerve
Vagus fibres
emerge from the medulla via the jugular foramen•
