Book Name: The Human Brain Book: An Illustrated Guide to Its Structure, Function, and Disorders
Author: Rita Carter
File size: 66 MB
File format: PDF
The Human Brain Book: An Illustrated Guide to Its Structure, Function, and Disorders Pdf Book Description:
The human brain is like nothing else. As organs go, it is not especially prepossessing—3lb (1.4kg) or so of rounded, corrugated flesh with a consistency somewhere between jelly and cold butter. It doesn’t expand and shrink like the lungs, pump like the heart, or secrete visible material like the bladder. If you sliced off the top of someone’s head and peered inside, you wouldn’t see much happening at all. Given this, it is perhaps not surprising that for centuries the contents of our skulls were regarded as relatively unimportant. When they mummified their dead, the ancient Egyptians scooped out the brains and threw them away, yet carefully preserved the heart. The Ancient Greek philospher, Aristotle, thought the brain was a radiator for cooling the blood. René Descartes, the French scientist, gave it a little more respect, concluding that it was a sort of antenna by which the spirit might commune with the body. It is only now that the full wonder of the brain is being realized.
The most basic function of the brain is to keep the rest of the body alive. Among your brain’s 100 billion neurons, some regulate your breathing, heartbeat, and blood pressure and others control hunger, thirst, sex drive, and sleep cycle. In addition to this, the brain generates the emotions, perceptions, and thoughts that guide your behavior. Then it directs and executes your actions. Finally, it is responsible for the conscious awareness of the mind itself. The brain is particularly difficult to investigate because its structures are minute and its processes cannot be seen with the naked eye. The problem is compounded by the fact that its most interesting product, consciousness, does not feel like a physical process, so there was no obvious reason for our distant ancestors to associate it with the brain. Nevertheless, over the centuries, philosophers and physicians built up an understanding of the brain and, in the last 25 years with the advent of brain-imaging techniques, neuroscientists have created a detailed map of what was once an entirely mysterious territory.