1 The Birth of Science - MSRI

122 5. Medicine and Other Empirical Sciences
ical concepts and terms still used today are directly traceable to him. For page 162
instance, it was Herophilus who first described the liver and the digestive
system, distinguishing the intestine’s various tracts and giving them some
of the names still used today (often in Latin translation), such as duodenum
and jejunum. 2
His most interesting discoveries were probably about the nervous system.
Before Herophilus the role of the brain had not been clearly identified;
some thinkers had intuited it correctly, but Aristotle thought that it
consisted in cooling the blood. 3 Herophilus was the first to describe the
anatomy of the brain; most importantly, he discovered the nerves, 4 whose
existence was previously unknown, and, having understood their function,
he distinguished between sensory and motor nerves. We know that
among the pairs of cranial nerves described by Herophilus were the optic,
oculomotor, trigeminal, motor root of trigeminal, facial, auditory and
hypoglossal. 5
Herophilus co-founded the anatomy of the circulatory system (which
also owes much to Erasistratus). He described the heart’s cavities and
valves 6 and was the first to identify and describe the anatomical differences
between arteries and veins, whose functional distinction had been
established by his teacher Praxagoras of Cos. The introduction of specific
terms such as calamus scriptorius (“writing quill”) for the narrow lower
end of the floor of the fourth ventricle of the brain and torcular Herophili
(see page 127) for the confluence of the four cranial venous sinuses gives
an idea of how detailed his description of the vascular system was. He
made equally significant contributions to respiratory and reproductive
anatomy; it was Herophilus, for example, who discovered the ovaries and
the so-called Fallopian tubes, and gave an accurate description of the spermatic
ducts (including the epididymis, which he discovered and named
with the term still used).
Herophilus paid particular attention to the eye, the only organ to which page 163
it is said he devoted a specific treatise. His was the first description of the
retina, which he named arachnoides (“like a spider’s web”), and of three
other membranes, probably to be identified with the sclera (and cornea),
the iris and the choroid.
2
The duodenum was so called because of its length of twelve finger-widths, and the jejunum
because it was normally found empty upon dissection.
3
Aristotle, De partibus animalium, II, 7, 652a, 24 – 653a, 36.
4
This is demonstrated in [Solmsen].
5
See Galen, De anatomicis administrationibus, 9.9 = [von Staden: H], text 82.
6
Galen says that the heart valves were described more accurately by Erasistratus (Galen, De
placitis Hippocratis et Platonis, I, 10, 3–4 = [von Staden: H], text 119).
Revision: 1.9 Date: 2002/09/14 19:12:01