2 ques on with complete solu on 2026
Herophilus
From Chalcedon
330/320-260/250 BCE
student of Praxagoras of Cos, (4th century)
moved to Alexandria as a colonist
Erasistratus
From Iulis
320/310-250/240 BCE
student of Chrysippus of Cnidus, (4th century)
moved to Alexandria as a colonist, then perhaps on to An*och (modern Turkish/Syrian
border)
Vivisec*on
no Greek linguis*c equivalent
analysis of biological structure and func*on
living organism
Herophilus and Erasistratus did this in the best way by far when they cut open men who
were alive, criminals out of prison, received from kings
Alexandria
earliest evidence of systema*c dissec*on
for non-human organisms, Aristotle
for human beings, Herophilus and Erasistratus
preserved in Celsus, De Medicina 1st century CE
this where library is and we find evidence for state funded research
Erasistratus discoveries
neurology
motor and sensory nerves
cardiac anatomy
iden*fied the four chambers of the heart
described structure and func*on of
tricuspid, mitral, aor*c, and pulmonary valves
,recorded that they prevented reversal of blood flow
heart's ac*on was like a bellows
Herophilus discoveries
in brain
ventricles
calamus scriptorius (part of brainstem)
torcular Herophili (confluence of the sinuses)
in eye
four membranes of eye
viscera
duodenum, liver, hepa*c/pancrea*c duct?
reproduc*ve organs
epididymis and vas deferens in men
Fallopian tubes and ovaries in women
angiology
difference between arteries and veins
Erasistratus on Experiment
Medicine must make ac*ve interven*on to understand underlying causes
Observa*on is necessary but not sufficient
ex. bird experiment
Eristratus on Diges*on
Mechanical processes
Solids
stomach grinds and crushes food like a mill-stone
not ripening or cooking
Liquids
nutri*on filtered
kidneys, liver, bladder
Mechanical metaphors
Herophilus on the pulse
, Dis*nc*on b/w arteries and veins, Praxagoras
Herophilus explains dis*nc*on
arteries have a coat 6x thicker/ veins (fr. 116 vS)
Isolates pulsa*on to arteries, as norm
pulsa*on of arteries natural not pathological
Characteris*cs of Herophilus' pulse
1) amount
2) size
3) speed
4) vehemence
5) rhythm
Galen On Dis*nguishing Pulses 4.3, 8.959K = Herophilus fr. 162.77-88 vS
What is the pulse good for?
Diagnos*c tool
baseline, normal pulse
contrasted with pulse taken
evaluated by 4/5 criteria given for pulse characteris*cs
Herophilus' *ming of the pulse by water-clock
Erasistratus' heart as a bellows
Similari*es concern ac*on of heart in a sta*c state
Focus aEen*on on heart as center of vascular system
Fluids move through heart in separate systems
air
blood
Heart func*on: expands and contracts
Pump does not
Bellows does
Erasistratus and mechanics
Many natural bodily ac*ons 'machine-like'
diges*on, grinding like mill-stone
liver, kidneys, bladder, filters
heart's contrac*on and expansion, bellows
Image of the body and nature