Low kick sciatic nerve, which is the longest and widest nerve in the human body, beginning in the lower back and running through the buttocks all the way to the lower limb, is a frequent target for low kicks. The most common defense against a low kick is known as "checking", where the leg is bent and brought up to protect the thigh. This causes the kicker to slam their shin into the defending fighters' shin or knee, causing pain and damage to the offender. In some instances, a well executed check of a low kick can break the leg of the
Optic nerve (dura, arachnoid, and pia mater) rather than the epineurium, perineurium, and endoneurium found in peripheral nerves. Fiber tracts of the mammalian central nervous system (as opposed to the peripheral nervous system) are incapable of regeneration, and, hence, optic nerve damage produces irreversible blindness. The fibres from the retina run along the optic nerve to nine primary visual nuclei in the brain, from which a major relay inputs into the primary visual cortex. The optic nerve is composed of retinal ganglion cell axons and glial cells. Each human optic nerve contains between 770,000 and 1.7 million nerve fibers, which are axons