Nerves

Front 1

olfactory funtion/origin

Back 1

F: purely sensory - carries afferent impulses associated with the sense of smell.
O: fibers arise from olfactory epithelium and run through cribiform plate of ethmoid bone to synapse in olfactory bulbs

Front 2

Optic function

Back 2

F: purely sensory - carries afferent impulses associated with vision
O: fibers arise from the retina of eye to form the optic nerve and pass through optic canal of orbit. Fibers partially cross over at the optic chiasma and continue on to the thalamus as optic tracts. Final fibers of this pathway travel from the thalamus to the visual cortex as the optic radiation.

Front 3

Oculomotor function/origin

Back 3

F: primarily motor - somatic motor fibers to inferior oblique and superior, inferior, and medial rectus muscles, which direct eyeball, and to levator palpebrae muscles of the superior eyelid. Parasympathetic fibers to iris and smooth muscle controlling lens shape (reflex response to varying light intensity and focusing of eye for near vision).
O: fibers emerge from dorsal midbrain and course ventrally to enter the orbit. They exit from skull via superior orbital fissure.

Front 4

Trochlear function/origin

Back 4

F: primarily motor - provides somatic motor fibers to superior oblique muscle that moves the eyeball.
O: fibers emerge from midbrain and exit from skull via superior orbital fissure.