then the system is called a severe tropical cyclone. These are referred to as hurricanes or typhoons in other countries. The circular eye or centre of a tropical cyclone is an area characterised by light winds and often by clear skies. Eye diameters are typically 40 km but can range from under 10 km to over 100 km.hen the system is called a severe tropical cyclone. These are referred to as hurricanes or typhoons in other countries. The circular eye or centre of a tropical cyclone is an area characterised by light winds and often by clear skies. Eye diameters are typically 40 km but can range from under 10 km to over 100 km.
A UCLA Health answered. Alzheimer's disease affects the brain. The disease causes degeneration of brain tissue and nerve cells. With less nerve cells present, it becomes harder for the brain to communicate with the body and function properly. Specifically, the neurotransmitter (a chemical that passes among cells relaying messages) acetylcholine isn't produced at a high enough volume.
Alzheimer's disease is a progressive condition that destroys the connections between cells in the brain. Eventually these cells die, which affects how the brain works. As cells die in the outer layer of the brain-called the cortex-it shrinks, and the spaces in the brain get larger.he cortex includes the hippocampus, which is an area of the brain that helps new memories form. The damage to the brain eventually causes problems with memory, intelligence, judgment, language, and behavior. Alzheimer's is the most common form of mental decline, or dementia, in older adults.