Cranial Nerves | orginates from cerebrum

12 pairs of cranial nerves

Ten of the twelve cranial nerves originate from the brainstem, anywhere on the midbrain, pons, or medulla oblongata

12 pairs of cranial nerves

two of the twelve cranial nerves originate from the cerebrum which travels via tracts in the cerebral cortex.

How many are SENSORY nerves

• 3 cranial nerves are sensory nerves whose axons have purely sensory functions only (I, II, VIII)

how many are MIXED nerves (contains both)

4 cranial nerves are mixed nerves that contain both sensory and motor axons (V, VII, IX, X)

how many are MOTOR nerves?

5 are motor nerves that contain primarily motor axons only (III, IV, VI, XI, XII)

what is a CN I Olfactory Nerve

It is a purely sensory nerve that innervates the olfactory mucosa in the superior nasal cavity, where it provides for the special sense of smell. Once the signal travels from the olfactory nerve it then synapses with the olfactory bulb, which then sends the impulses down the axons of the olfactory tract to the olfactory cortex

whats its orgain and passage of this nerve?

• Origin: It is located superior to the midbrain and CN II Optic Nerve. It originates from the cerebrum, not the brainstem

• Passage: It passes through the cribriform foramina of the ethmoid bone

Find the CN I Olfactory Nerve

CN I OLFACTORY NERVE

what is a CN II Optic Nerve

This is also a purely sensory nerve that provides for the sense of vision. Its axons emerge from the retina of the eye and meet at the optic chiasma, where the nerves partially exchange axons before diverging to form the optic tracts

whats its orgin and passage of this nerve?

• Origin: It is located superior to the midbrain. It originates from the cerebrum, not the brainstem

• Passage: It passes through the optic canal of the sphenoid bone

where is the CN II Optic Nerve located

CN II OPTIC NERVE

where is the Optic Chiasma

OPTIC CHIASMA