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.
Parts of the Nervous System. The center of the nervous system is the brain. The brain takes in what your eyes see and ears hear, and if you decide that you want to move around, your brain tells your muscles to do it. Your brain makes your muscles move by sending tiny electrical signals to them through your nerves. Peripheral nervous system (PNS): a part of the nervous system which includes all the nerves outside of the brain and spinal cord. 2  Sympathetic nervous system: The part of your nervous system that unconsciously controls your organs and glands when you're excited or frightened.
EYE STRUCTURE AND FUNCTION Eye is like a camera. The external object is seen like the camera takes the picture of any object. Light enters the eye through a small hole called the pupil and is focused on the retina, which is like a camera film.Eye also has a focusing lens, which focuses images from different distances on the retina. The colored ring of the eye, the iris, controls the amount of light entering the eye.It closes when light is bright and opens when light is dim. A tough white sheet called sclera covers the outside of the eye. Front of this sheet (sclera) is transparent in order to allow the light to enter the eye, the cornea.he colored ring of the eye, the iris, controls the amount of light entering the eye. It closes when light is bright and opens when light is dim. A tough white sheet called sclera covers the outside of the eye. Front of this sheet (sclera) is transparent in order to allow the light to enter the eye, the cornea.