Has two nuclei: oculomotor nucleus and the Edinger-Westphal nucleus. (T/F)
Runs in the lateral wall of the cavernous sinus. (T/F?)
Enters orbit through the inferior orbital fissure. (T/F?)
Its upper division supplies the superior rectus and the superior oblique muscles. (T/F?)
Its inferior branch innervates medial rectus, inferior rectus and inferior oblique muscles. (T/F?)
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The Edinger–Westphal nucleus or accessory oculomotor nucleus is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.
It enters the orbit via the superior orbital fissure.
Henry Vandyke Carter [Public domain], via Wikimedia Commons
The upper division supplies the superior rectus muscle and levator palpebrae superioris (elevating muscle of upper eyelid). The superior oblique muscle is innervated by the trochlear nerve (the fourth cranial nerve).
Is covered with all three meningeal layers. (T/F?)
Leaves the orbit through superior orbital fissure. (T/F?)
Is not affected with Guillain–Barré syndrome. (T/F?)
Some of its axons terminate in the pretectal nuclei. (T/F?)
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The first is the olfactory nerve.
The optic nerve is, actually, a part of the central nervous system because it is developed from the outgrowth of the diencephalon (optic vesicle, optic stalk). It is composed of retinal ganglion cells and glial cells and is covered by myelin produced by oligodendrocytes.
They follow the nerve as it grows from the diencephalon.
Henry Vandyke Carter [Public domain], via Wikimedia Commons
It goes through the optic foramen and continues through the optic canal.
Henry Vandyke Carter [Public domain], via Wikimedia Commons
Hmm… GBS is primarily a peripheral demyelinating disease and it should not affect the optic nerve or any other part of CNS, but…
Is the second shortest of the cranial nerves. (T/F?)
Emanates from the brainstem like all of the cranial nerves. (T/F?)
Travels through cribriform plate of the ethmoid bone. (T/F?)
Tumors of the frontal lobe of the brain can cause damage to the olfactory nerve. (T/F?)
Lesions of the olfactory nerve lead to a reduced ability to sense pain from the nasal epithelium. (T/F?)
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Olfactory nerve is the shortest of the cranial nerves.
Olfactory nerve fibers arise from olfactory receptor cells located in the olfactory epithelium in the upper parts of the nasal cavity. They pass through the cribiform plate of the ethmoid bone to synapse in the olfactory bulb which lays in the anterior cranial fossa. The only other cranial nerve that does not join the brainstem is optic nerve.
Is the smallest cranial nerve in terms of the number of axons it contains. (T/F?)
Has the shortest intracranial length. (T/F?)
Is the one of two cranial nerves that exit from the dorsal (rear) aspect of the brainstem. (T/F?)
Innervates superior oblique muscle, on the opposite side (contralateral) from its origin. (T/F?)
Emerges from the dorsal aspect of the brainstem at the level of the caudal mesencephalon, just below the inferior colliculus, (T/F?)
Enters the orbit through the superior orbital fissure. (T/F?)
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It is the smallest in terms of the number of axons it contains. The shortest is the olfactory nerve.
Trochlear nerve has the longest intracranial length.
Trochlear nerve is the only cranial nerve that exits from the dorsal aspect of the brainstem.
Henry Vandyke Carter [Public domain], via Wikimedia Commons
It is the only cranial nerve with contralateral innervation. It decussates within the mesencephalon before emerging on the opposite side of the brainstem. An injury to the trochlear nucleus in the brainstem will result in an contralateral superior oblique muscle palsy, whereas an injury to the trochlear nerve (after it has emerged from the brainstem) results in an ipsilateral superior oblique muscle palsy.
