The history of neurology goes back to ancient Egypt. Scrolls depict disorders of the brain. They had a basic understanding of the nervous system. Egyptians even performed simple brain surgery.In ancient Greece, the famous physician Hippocrates was convinced epilepsy had a physical cause. Before him, it was considered a punishment by the gods. Another Greek physician, Galen, looked at the nervous system in specimens. He cut a certain nerve in the brain of an ape. Then he noticed the ape lost its voice.In 1664, Thomas Willis published Anatomy of the Brain. In it he described the circle of Willis, which enables the flow of blood through the brain. He was also the first to use the word neurology. In the 1700s, Bailie and Cruvielher published the first illustrations of the brain. This helped doctors and scientists. They began to understand diseases such as brain damage in stroke.In 1837, J. E. Purkinje was the first to look at a neuron. He saw it through a microscope. This led to an understanding that progressed pastcrudedrawings. The famous philosopher Rene Descartes thought about the brain. He had a theory about behavior.Hethought every activity of an animal was a necessary reaction to an external stimulus. Some doctors experimented on patients. They were able to understand more about the nervous system.A new understanding of neurological behavior was reached by Pavlov, a Russian physiologist. He trained his dogs to salivate at the ring of a bell. This established that a simple reflex could be modified by higher brain functions. By 1878, William McEwen removed a brain tumor from a patient. The patient lived for many years after. When he performed his surgeries, he used tools such as the tendon hammer. X-rays and the CT scan were not far behind. These developments led to the field of neurology that helps people today.The word “he” in paragraph 4 refers to which of the following…