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.
Fast facts on Alzheimer's disease. Here are some key points about Alzheimer's. More detail and supporting information is in the main article. 1  Alzheimer's disease is the most common type of dementia. 2  The term dementia describes a loss of mental ability associated with gradual death of brain cells.3  There are an estimated 5.3 million Americans of all ages with Alzheimer's disease.or this reason, and because symptoms could signal any of a number of diagnoses, it is always worthwhile seeing a doctor. Alzheimer's disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline.