Question

At least 12 structures/tissues the Action Potential must travel through to reach the Primary Visual Cortex

Answer 1

Light from an object traverses though structures like Cornea, Aquous humour ,Lens, vitreous humour falls into retina where it is transduced into action potential by photorecepto cells. The generated action potential then has to traverse many tissues to ultimately reach the primary visual cortex where that is interpreted and we see the object. The structures that a generated action potential gets to traverse are as follows:

A)Optic Nerve: it is the 2nd cranial nerve which receives action potential from the retina.It has a head, an intraorbital part,an intracanalicular part and an intracranial course.

B) Optic chiasma: It is the point of bilateral optic nerve decussation.

C)Optic tract:it is the caudolateral continuation carrying fibers from contralateral visual field.

D)Lateral geniculate body:These are two rounded protuberance on the either side of diencephalon where nerve fibers of ipsilateral optic tract relay.

E) Optic radiation: It arises from the respective lateral geniculate body.

F)Visual cortex: Finally the action potential reaches the Primary visual cortex ( Broadman area no. 17).