OCB04-2003 Cranial nerves Overview Flashcards
What are cranial nerves attached to?
The forebrain and brainstem
What are spinal nerves attached to?
The spinal cord
Which part of the spinal cord does sensory information come from the periphery?
The dorsal part
Which part of the spinal cord do motor neurons receive information from the cortex?
Ventral part
What is the cranial nerve pathway? Use trigeminal as an example
There is trigeminal ganglion in the brain which will go into the sensory nucleus in the brainstem- this ganglion is equivalent to the dorsal root ganglion outside the spinal cord
What is the name of each cranial nerve?
I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Vestibulocochlear IX Glossopharyngeal X Vagus XI Accessory XII Hypoglossal
Which cranial nerves originate from the brainstem?
All except I, II and IX
Where does the olfactory nerve originate?
From the cribiform plate of the ethmoid bone, which will enter the forebrain
What is the difference between the optic nerve and optic tract?
Optic nerve only has visual information coming from one eye as it lies before the optic chiasm
The optic tract has sensory visual information coming from both eyes as the fibres have decussated after the chiasm
Which cranial nerves emerge from the anterior portion of the brain?
I Olfactory
II Optic
III Oculumotor
IV Trochlear
Which cranial nerves emerge from the pons?
V Trigeminal
VI Abducens
VII Facial
Wher does the vestibulocochlear nerve arise and go to?
Arises in the inner ear and goes to the pons
Which nerves arise from the medulla oblongata?
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal
Why are there no synapses in the ganglion?
They are just a collection of cell bodies of sensory neurons
Where do the two optic nerves cross over at?
The level of the optic chiasm
What nerves is the ethmoid bone associated with?
The olfactory nerve, where the neuron lies in the cribriform plate
What nerves are associated with the sphenoid bone?
Everything associated with the eye and movement
Optic, oculomotor, trochlear and abducens
Also the trigeminal nerve runs through it
What nerves are associated with the temporal bone?
With hearing where the vestibulocochlear nerve runs through
Also has the glossopharyngeal, vagus and spinal accessory nerve running through
What nerves are associated with the occipital bone?
The hypoglossal nerve runs through the foramen magnum
Which nerves are sensory only?
I Olfactory
II Optic
VIII Vestibulocochlear
Which nerves are motor only?
III Oculomotor IV Trochlear VI Abducens XI Accessory XII Hypoglossal
Which nerves are both motor and sensory?
V Trigeminal
VII Facial
IX Glossopharyngeal
X Vagus
What is associated with sensory only fibres?
Afferent
What is associated with motor only fibres?
Efferent
What functions do cranial nerves allow us to carry out?
Chewing and swallowing Talking Looking Non-verbal communication Hearing
What is the cutaneous sensory supply of the cranial nerves?
Scalp
Face
neck
What is the non-cutaneous regions of the sensory supply?
Oral cavity Cornea Nasal Cavity Paranasal sinus Pharynx Larynx Tympanic membrane
What is the motor supply of the cranial nerves to?
Muscles of facial expression Muscles of mastication Extra-ocular muscles Muscles of the tongue Muscles of pharynx and larynx Cervical muscles