The abducens nerve (cranial nerve VI) leaves the brainstem at the junction of the pons and the medulla oblongata, just above the medullary pyramid and inward of the facial nerve. From there it runs up along the clivus, passes under the dura through Dorello’s canal, turns forward through the cavernous sinus beside the internal carotid artery and enters the eye socket through the superior orbital fissure to reach the lateral rectus muscle. [1]
The 3D brain needs JavaScript. The text below still says where the abducens nerve is and what it does.
The pons and medulla oblongata are lit together; the abducens nerve leaves at their border and is not drawn on its own. The side (sagittal) slice button cuts through them. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Not a separate shape in this atlas; lit: the part it leaves the brain from. Lit: the whole pons and the whole medulla oblongata together, since the abducens nerve leaves at their border. The nerve itself, which runs on to the eye socket, has no shape in the BodyParts3D model, so nothing is drawn for it at a guessed point. [2][1]
Where it leaves the brain: the border of the pons and the medulla oblongata (the pontomedullary junction), above the pyramid of the medulla and closer to the midline than the facial nerve. [1][3]
Lit here: the pons and the medulla oblongata, the parts the abducens nerve leaves the brain from, at their border — see each on its own page.
Next to it, each lit on its own page: facial nerve.
Where it is
Its cell bodies sit in the abducens nucleus, in the pons on the floor of the fourth ventricle, close to the midline. Fibres of the facial nerve loop around this nucleus and raise a small bump on that floor, the facial colliculus. [1]
Its course to the eye is long: from the brainstem it runs up between the pons and the clivus of the skull, pierces the dura and passes beneath it through Dorello’s canal, bends sharply forward over the tip of the petrous temporal bone and runs through the cavernous sinus beside the internal carotid artery. [1]
It enters the eye socket through the inner end of the superior orbital fissure, passing through the common tendinous ring, the same fissure the oculomotor (III) and trochlear (IV) nerves use. [1][4]
What it does
It works a single muscle on each side, the lateral rectus, one of the six muscles that move the eye; the lateral rectus turns the eye outward, towards the temple (abduction, which gives the nerve its name). [1][5]
It is a purely motor nerve: its fibres are of the general somatic efferent type and carry no feeling. [1][5]
Looking to one side moves both eyes together: the abducens nucleus holds, besides the motor cells for its own lateral rectus, interneurons that cross the midline to the oculomotor nucleus driving the medial rectus of the other eye. The medial longitudinal fasciculus links the abducens, trochlear and oculomotor nuclei into one unit. [1]
Connections
From the brain: motor fibres from the abducens nucleus in the pons run forward and down through the pons, beside the corticospinal tract, before leaving at the pontomedullary junction. Its target: the lateral rectus muscle of the eye on the same side. [1]
Other names
Cranial nerve VI (CN VI), sixth cranial nerve; nervus abducens (Latin). Terminologia Anatomica accepts two English names, abducens nerve and abducent nerve; “abducens” is more common in recent literature and is the term used by MeSH and Gray’s Anatomy. [1]
Size
The model has no shape for the abducens nerve, so it is not measured here. The pons, lit as the part it leaves the brain from, measures about 34 mm front to back, 29 mm top to bottom and 42 mm side to side on this model (the box it fits in, not its volume). [2]
The medulla oblongata, lit as the part it leaves the brain from, measures about 33 mm front to back, 41 mm top to bottom and 27 mm side to side on this model (the box it fits in, not its volume). [2]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.