I - Optic nerve 

II - Olfactory nerve 

III - Oculomotor nerve

IV - Trochlear nerve

V - Trigeminal nerve

VI - Abducens nerve

VII - Facial nerve

VIII - Acoustic (vestibulocochlear) nerve 

IX - Glossophrayngeal nerve

X - Vagus nerve

XI - Spinal accessory nerve 

XII - Hypoglossal nerve

Remember the 12 nerves in the following order

On Old Olympus Towering Tops, A Finn And German Viewed Some Hops

If you confuse which comes first (Optic or Olfactory) remember:

• You have I nose. You have II eyes. (I - Olfactory; II -- Optic)

An axon are tiny connections in the nervous system from where electrical signals move to other neurons. Thats how your brains tell you someone is touching you, or you are feeling pains for example.

In Central Nervous System, CNS (including CN II), myelin is synthesized by oligodendrocytes.

In Peripheral Nervous System, PNS (including CN III-XII), myelin is synthesized by Schwann cells.

Mnemonic: 

COPS (CO PS) 

CNS = Oligodendrocytes, 

PNS = Schwann cells.