Central nervous system - consists of the brain and spinal chord
Peripheral nervous system - consists of nerves, which lie outside the CNS. 12 cranial nerves that comes off from the brain and 31 spinal nerves that comes off from the spine.
Menopause/post menopause - lack of exercise, medication, stress
Alzheimer's disease - neurodegenerative disease that affects memory, caused by too much buildup of protein/plaque called amyloid, and loss of neurons in the brain
Stroke - blood clot that blocks the flow of blood and oxygen to the brain, symptoms include muscle weakness, face drooping, and difficulty speaking