Why did Columbus and others try to sail around the world?

You probably know that people native to the Americas are called “Indians” because early explorers like Christopher Columbus thought they had come across the Indian Spice Islands. Traders were forced to sail westward after the spice route to the East by land was blocked for Europeans by Muslim uprisings.

What Is Alzheimer’s Disease?

Alzheimer’s disease is a form of many different diseases of the brain that cause people to experience serious memory loss and confusion. Alzheimer’s disease is a progressive condition that affects a person’s brain cells. This means that the brain cells gradually die and more parts of the brain become damaged. The person’s symptoms will eventually become worse. The early stages of Alzheimer’s disease may become forgetful or have difficulty finding the right words for everything. One of the first symptoms is the loss of short-term memory (the ability to remember recent events). People with Alzheimer’s disease have a shortage of important chemicals in the brain called neurotransmitters. Neurotransmitters are responsible for the transmission of messages with the brain. These messages control functions such as memory, ability to think clearly, speech, and movement.