Neuroanatomy of Cranial Nerves Flashcards
Which is the only cranial nerve to exit the brain posteriorly?
Trochlear (CN IV)
Which is the only sensory nerve that does not synapse in the thalamus prior to reaching the cortex?
Olfactory
Where are the cell bodies of the olfactory receptor organs located?
In the olfactory organ (In the nasal mucosa)
What bony structure do the olfactory nerve fibres pass through?
The cribriform plate of the ethmoid bone
Where do the fibres of the olfactory nerve synapse?
In the olfactory bulb.
After the olfactory nerves have synapsed in the olfactory bulb what happens?
Second order neurones form the olfactory tract. This then terminates in the piriform cortex of the anterior part of the temporal lobe.
Name the two occulomotor nerve nuclei
- Somatic motor nucleus of the occulomotor nerve.
- The visceral motor (parasympathetic) accessory/edinger westphal nucleus of the occulomotor nerve
What are the two distinct functions of the occulomotor nerve?
- Somatic motor (movement of 4 extra occular muscles)
2. Parasympathetic (through the ciliary ganglion to the sphincter pupillae to cause pupil constriction)
Which part of the occulomotor nerve is associated with the edinger westphal nucleus?
Parasympathetic
Which part of the occulomotor nerve is associated with the occulomotor nucleus?
Somatic motor
What part of the brain does the occulomotor nerve arise from?
Midbrain
Through what structure does the occulomotor nerve leave the cranial cavity?
Superior orbital fissure
Where is the trochlear nerve nucleus is relation to the occulomotor nucleus?
Immediately inferior
Where does the trochlear nerve exit the cranial cavity?
Superior orbital fissure
Which nerve has the longest intracranial course?
Trochlear
