Unlike Alzheimer's disease, which shrinks the hippocampus causing progressive memory loss, white matter disease is a more diffuse mind-robbing condition that targets small blood vessels deep within the brain's white matter. The disease hardens the tiny arteries, gradually restricting nutrients to white matter -- the connections between brain regions involved in executive abilities such as planning, organizing, problem-solving, and attention.
The eye is a part of the nervous sytem, which is essentially a network of neurons that coordinate actions and transmits signals throughout the body. There are two parts to the â¦ nervous system: central and peripheral.he nervous system. Your eyes are part of your brain. The majority of. your brain surface is light-sensitive.
The eye is a slightly asymmetrical globe, about an inch in diameter. Just behind the iris and pupil lies the lens, which helps to focus light on the back of the eye. Most of the eye is filled with a clear gel called the vitreous. Light projects through the pupil and the lens to the back of the eye. The inside lining of the eye is covered by special light-sensing cells that are collectively called the retina. The retina converts light into electrical impulses. Behind the eye, the optic nerve carries these impulses to the brain. The macula is a small extra-sensitive area within the retina that gives central vision. It is located in the center of the retina and contains the fovea, a small depression or pit at the center of the macula that gives the clearest vision. Eye color is created by the amount and type of pigment in the iris.