Iatrophysics
[2] It was related to iatrochemistry in studying the human body in a systematic manner based on observations from the natural world though it had more emphasis on mathematical models rather than chemical processes.
[3] Iatrophysicists drew inspiration from various established physical phenomena in order to explain how certain biological processes took place and how this can be applied towards medicine.
Some models came into existence before Isaac Newton's formulation of his three laws in classical mechanics, drawing on basic principles of statics and dynamics to represent how a biological system behaved.
Giovanni Borelli was prolific in applying mechanics to a wide variety of humans and animals in different degrees of activity, drawing upon an array of simple machines and models for translational and rotational motion and equilibrium.
System consisted of arteries, veins, and vasculature verified through experiment and microscope by Marcello Malpighi's observations of capillaries in animal lung tissue.
Albrecht von Haller, as did Borelli, postulated that friction from the blood on vessel walls lead to body heat and even fever.
A hydraulic model for motion by René Descartes implied the body had a system that maintained flow between the brain and muscles in equilibrium state through nerves and blood vessels.
[8] Starting in the 17th century, quantitative fields such as physics and mathematics began gaining legitimacy as a means of studying the natural world with the advent of theory, practices, and instruments.
The development of medical instruments and techniques, such as the microscope and detailed dissections, changed how natural philosophers thought about how to explain the human body's properties.
On a macroscopic scale through observation and anatomy, some iatrophysicists such as Borelli focused on explaining how muscles worked in conjunction together to form movements with dynamics or physical models.
On a microscopic scale via observation and dissection, the contractility of muscle was to be explained by pneumatic expansion, a popular explanation supported by Descartes and Borelli, or inherent shape deformation, postulated by Nicolas Steno and Albrecht von Haller to an extent, based upon principles of fluids and statics.
[7][10] A colleague of Marcello Malphigi, Borelli was a mathematician who made connections between what he observed in living things and inanimate but relatively simple systems.
He dissected animals and examined how muscles were to increase mechanical advantage, observed how a variety of living things performed different movements and activities such as running, carrying loads, swimming, and flying naturally rather than by his intervention, and devised simple methods to calculate a person's center of mass.
He also devised relatively simple experiments and devices to make his observations such as a plank and rod for center of mass and a spirometer for volume of air.
He attempted to model various phenomena such as the brain, movement, sleep, circulation, and senses with analogies to inanimate objects such as reservoirs, pipes, lenses and steam engines that often sought to maintain an equilibrium for certain states.
To test his claim, Harvey dissected human corpses and animals and, based on his anatomical findings, devised a simple demonstration of how arteries and veins continuously carried blood throughout the body.
To establish a mathematical relationship between food/water intake and excretion, Santorius designed a special chair that had a balance that weighed a subject's meal and consequent excrement.
The most popular explanation, supported by well known Iatrophysicists such as Descartes and Borelli, asserted that the heart contracted from its fibers inflating themselves through a chemical reaction.
However, the philosophies of Aristotle, Hippocrates, and Galen began to wane in popularity, replaced by anatomical and philosophical schools of thought based on mechanics and chemical naturalism.
The decline of Galenic philosophy-based medicine coupled with the rise of new ideologies was spurred by the advent of new discoveries in anatomy and physiology, such as that of William Harvey's work centered on circulation of the blood.
Newtonian physics came to widely influence the way the body was viewed, and physiology was increasingly focused on a clockwork mechanism, and the later hydraulics was even applied to the movement of bodily fluids.
