Dissection
Human dissections were carried out by the Greek physicians Herophilus of Chalcedon and Erasistratus of Chios in the early part of the third century BC. During this period, the first exploration into full human anatomy was performed rather than a base knowledge gained from 'problem-solution' delving. While there was a deep taboo in Greek culture concerning human dissection, there was at the time a strong push by the Ptolemaic government to build Alexandria into a hub of scientific study. For a time, Roman law forbade dissection and autopsy of the human body, so physicians had to use other cadavers. Galen, for example, dissected the Barbary macaque and other primates, assuming their anatomy was basically the same as that of humans.
Tracheotomy
Despite the concerns of Hippocrates, it is believed that an early tracheotomy was performed by Asclepiades of Bithynia, who lived in Rome around 100 BC. Galen and Aretaeus, both of whom lived in Rome in the 2nd century AD, credit Asclepiades as being the first physician to perform a non-emergency tracheotomy. Antyllus, another Roman-era Greek physician of the 2nd century AD, supported tracheotomy when treating oral diseases. He refined the technique to be more similar to that used in modern times, recommending that a transverse incision be made between the third and fourth tracheal rings for the treatment of life-threatening airway obstruction.