Erasistratus wrote many works on anatomy, practical medicine and pharmacy, of which only the titles remain, together with a great number of short fragments preserved by
Galen,
Caelius Aurelianus, and other ancient writers. These, however, are sufficient to enable us to form a reasonable idea of his opinions both as a
physician and an
anatomist. It is as an anatomist that he is most celebrated, and perhaps there is not one ancient physician that did more to promote that branch of medical science than he. He appears to have been very near the discovery of the
circulation of the blood, for in a passage preserved by Galen he says: The vein arises from the part where the arteries, that are distributed to the whole body, have their origin, and penetrates to the sanguineous [or right] ventricle [of the heart]; and the artery [or pulmonary vein] arises from the part where the veins have their origin, and penetrates to the pneumatic [or left] ventricle of the heart. The description is not very clear, but seems to show that he supposed the
venous and
arterial systems to be more intimately connected than was generally believed. This idea is confirmed by another passage in which he is said to have differed from the other ancient anatomists, who believed that the veins arise from the
liver, the arteries arise from the heart and the heart is the origin both of the veins and the arteries. With these ideas, it can have been only his belief that the arteries contained air and not blood, that hindered his anticipating
Harvey's discovery. These views also supported his belief that blood production started in the liver, and not the heart. This, however, appears to be an oversight, as Galen attributes it not to him, but to one of his followers. Erasistratus also made observations on the morphology of the heart, describing the pulmonary artery and the aorta to have a sigmoid shape, a name which is still used presently. he speaks as if he had himself dissected a human brain. Galen says that before Erasistratus had more closely examined into the origin of the
nerves, he imagined that they arose from the
dura mater and not from the substance of the brain; and that it was not until he was advanced in life that he satisfied himself by actual inspection that such was not the case. According to
Rufus of Ephesus, he divided the nerves into those of sensation and those of motion, of which the former he considered to be hollow and to arise from the membranes of the brain and the latter from the substance of the brain itself and of the
cerebellum. He asserted that the
spleen, the
bile, and several other parts of the body, were entirely useless to animals. Erasistratus believed that fluids, when drunk, passed through the
esophagus into the stomach. During his time, there was controversy that was carried on as to whether fluids when drunk passed through the
trachea into the
lungs, or through the
esophagus into the stomach. He is also supposed to have been the first person who added to the word
arteria, which had hitherto designated the canal leading from the mouth to the lungs, the epithet
tracheia, to distinguish it from the arteries, and hence to have been the originator of the modern name
trachea. He attributed the sensation of
hunger to emptiness of the
stomach, and said that the
Scythians were accustomed to tie a belt tightly round their middle, to enable them to abstain from food for a longer time without suffering inconvenience. The
pneuma (spiritual substance) played a very important part both in his system of
physiology and
pathology: he supposed it to enter the lungs by the trachea, thence to pass by the pulmonary veins into the heart, and thence to be diffused throughout the whole body by means of the arteries; that the use of respiration was to fill the arteries with air; and that the pulsation of the arteries was caused by the movements of the
pneuma. He accounted for diseases in the same way, and supposed that as long as the
pneuma continued to fill the arteries and the blood was confined to the veins, the individual was in good health; but that when the blood from some cause or other got forced into the arteries, inflammation and fever was the consequence. Of his method of cure the most remarkable peculiarity was his aversion to
bloodletting and
purgative medicines: he seems to have relied chiefly on diet and regimen, bathing, exercise, friction, and the most simple vegetables. Erasistratus was against bloodletting likely due to his theory of
plethora. Much to the disagreement that
Galen had towards Erasistratus's views regarding
phlebotomy, the Alexandrian physician was said by
Galen in his work entitled,
Bloodletting, against the Erasistrateans at Rome, to have disregarded the importance of the practice and rather suggested alternative methods. Notably, Erasistratus suggests the bandaging of a patient's armpits and groin to achieve the desired results associated with
phlebotomy.
Galen continues in his work to highly criticize this viewpoint that the Alexandrian physician had regarding the medical practice, and points out that Erasistratus did not give enough evidence to support the avoidance of
phlebotomy for other treatments. == Association with Herophilus and Galen ==