THE BIOLOGY BOOK
Hippocrates (c. 460–c. 370 BCE), Galen (c. 130–c. 200), Emanuel Swendenborg (1688–1772), Domenico Cotugno (1736–1822)
The presence of “water” surrounding the brain was first recognized by Hippocrates and referred to by Galen as an “excremental liquid” in the ventricles (central cavity). For the next sixteen centuries, the scientific world was silent about or oblivious to cerebrospinal fluid (CSF).
Interest in CSF was renewed during the mid-1700s by Emanuel Swendenborg, a Swedish scientist, metallurgist, theologian, and mystic. After completing his studies and European travels, he returned to Sweden in 1715 and spent the next two decades working on scientific and engineering projects, such as a description of a flying machine. By his own admission, he was not an experimental scientist but rather preferred contemplating “facts already discovered, and eliciting their causes.” These included ideas about the nervous system—in particular, the brain. In a manuscript he prepared from 1741–1744, Swendenborg referred to CSF as “spirituous lymph” and a “highly gifted juice” that is dispensed from the roof of the fourth ventricle to the medulla oblongata and spinal cord; this paper was finally published in translation in 1887. At age 53, he experienced a spiritual awakening and devoted the remainder of his life to theological issues. His best-known work is a book on the afterlife, Heaven and Hell (1758).
Domenico Cotugno, an Italian physician and anatomy professor at the University of Naples, first described the circulation of the CSF by decapitating cadavers, standing them on their feet, and observing its flow; CSF has been referred to as Liquor Cotunni in his honor. CSF is formed in a central portion of the brain called the choroid plexus, and from there circulates and provides the brain and spinal cord with nutrients and carries away metabolic waste materials. Another major function involves serving as a shock absorber to provide protection to the head from sudden jerking or blows, thereby preventing the brain and skull from coming into contact; this cushion may be insufficient to guard against brain damage caused by automobile accidents or sports injuries. The CSF also provides buoyancy and supports the weight of the brain in the skull.
A major function of the cerebrospinal fluid is to serve as a shock absorber protecting the brain from injury that results from sudden jerking movements and blows to the head.