Unit II - C.N. III - Oculomotor Nerve Flashcards
What type of nerve is the oculomotor nerve?
motor
The oculomotor nerves supply all extraocular muscles except for which two?
Superior oblique
Lateral rectus
The oculomotor nerve carries both _______ and _____ fibers.
Somatic and parasympathetic (preganglionic)
Oculomotor nuclei are what type?
Somatic nuclei of origin
Oculomotor nuclei are located where?
In the periaqueductal gray matter, anterior to cerebral aqueduct.
The oculomotor nuclei are at the level what?
The superior colliculus
What part of the cerebral cortex sends axons TO the oculomotor nuclei?
B.A. 8 - motor cortex
What other two areas do the oculomotor nuclei receive information from?
Superior colliculus
Medial longitudinal fasciculus
Axons travel forward from nuclei and go through what area?
The red nucleus
After passing through the red nucleus the fibers exit the CNS through the ______ and go into the ______?
The interpeduncular fosse
cistern
Once the fibers leave the CNS what are they covered by what and why?
epineurium because now in PNS
After leaving the CNS the axons penetrate what?
The dura mater
After penetrating the dura mater the axons travel along the __________ and exit the skull through what opening?
Cavernous sinus
Superior orbital fissure
Once in the eye socket the oculomotor nerve splits into what?
Superior and inferior rami
What muscles are supplied by the superior ramus?
Superior rectus
Lavatory palpebrae superioris
The inferior rectus divides into three branches called?
Medial, central, lateral
The medial branch of the inferior rectus supplies what muscle?
Medial rectus
The central branch of the inferior rectus supplies what muscle?
Inferior rectus
The lateral branch of the inferior rectus supplies what muscle?
inferior oblique
The accessory oculomotor nucleus contains what type of fibers?
Preganglionic parasympathetic neurons
Axons from the accessory nucleus follow what?
The oculomotor nerve
Axons from the accessory nucleus synapse where?
In the ciliary ganglion
The ciliary ganglion is located ____ anterior to what?
1 cm
Superior orbital fissure
Postganglionic parasympathetic fibers from the ciliary ganglion follow the course of what?
The ciliary arteries
The postganglionic parasympathetic fibers from the ciliary ganglion pierce the ______ and travel along what?
sclera
The internal surface of the sclera
The fibers from the accessory oculomotor nuclei supply what muscles?
Papillary constrictor (aka sphincter pupillae) ciliaris muscle
Nerves leaving the ciliary ganglion also carry what two types of fibers?
Sympathetic and somatic sensory
Sympathetic and somatic sensory fibers that are also in ciliary ganglion were picked up from what?
The ophthalmic nerve -V1 - ophthalmic divison
Do these “other fibers” from V1 synapse in the ciliary ganglion?
No, they just pass through
