A common error is to think of medical photography as just one new specialty among many, yet medical illustration is as old as medicine itself and the present is only a very short interval of time between the past and the future. 
This is an invariable truth that paintings and illustrations are as old as mankind itself and photography itself is too young to compare. The precursor of photography was the Camera Obscura (Latin; camera for “vaulted chamber/room”, obscura for “dark”), which was invented only in 1457 and was mostly used by artists only as an aid to painting. Hence, the history of medical illustration cannot be ignored, as it has grown over a period of time that is much older the than concept of medical photography.
The evolution of medical illustration is the culmination of medical philosophy, science, and spirituality that has grown for centuries. The earliest medical texts were descriptive but devoid of visual images/illustrations. Later, texts were accompanied by illustrations and became an integral part of the medical education, because it became evident that knowledge of the different systems of the human body was indispensable in the medical practice. As knowledge of medical science was progressed, permitted by social, cultural and technological changes, the types of illustrations also become diversified from gross anatomy through dissections showing the various organ systems, histological preparations, and radiological & invisible light imaging, right up to the computerized digital image that is available today, that allows both two- and three-dimensional depictions to be transmitted electronically across the world in a matter of seconds. In the last century, medical illustration, in its infinite variety of techniques, has been developed as a profession in its own right, though not in Indian subcontinents.
The Ancient Evidence:
The primitive anatomy (of animals) had been represented in ancient cave-paintings, in primitively sculpted figures, and through all the ages in various forms of artistic expression. The earliest evidence of such illustration was prehistoric, before 75000 years ago to 3000 BC. The subject matter was the one most familiar, hunting as illustrated by some unknown hunter-artists.
On a prehistoric cave wall in the southern part of Europe, a hunter portrayed an elephant in crude illustration and in its chest demarcated a vital spot i.e. the heart. The unknown artist was aware that his arrows or spear worked more effectively on that spot. Similarly, on a wall of a Babylonian temple there is a figure of a wounded lion, with arrows stuck in its spine. The posterior limbs, which once had acted like spring to drive the creature, are tiresome stick-like; blood oozes from its wounds, and nose, as one arrow seemingly entered the lung; the forelimbs are in its last painful movements. Here, also some unknown artist gave us a visual document of an animal in pain.
The Journey From Antiquity to Post-Renaissance:
Ancient Egypt: The Egyptians, though possessing some sound fundamentals in medicine and art, were really never able to achieve the freedom and natural beauty of illustrations. Though, in the history of civilized mankind, Hellenistic anatomists like Herophilos (335–280 BC, deemed to be the first anatomist and started human dissection) of Alexandria in the 4th Century BC studied anatomy through diagrams to illustrate medical matters that were produced by them.
Persian Civilization: Early Persian civilization produced crude biological drawings, which were made principally as ornaments or portraiture on vases, columns, and tablets.
The Eastern World: Eastern and Western medicine began with similar fusions of religion, spirituality, and science. Anatomists resorted to analogies of the universe to explain the body when superstitions surrounding death, and the fate of the soul prevented closer observation through dissection. The Chinese were prevented by both moral and civil law from dissecting bodies and consequently from making anatomical drawings. (If you want to explore the divergence of Chinese and Western Medical Illustrations, here is the LINK to an outstanding article by Camillia Matuk).
Ancient Rome: The Romans produced medical illustrations that were, for the most part, battle scenes or delivery scenes with an attempt at emphasizing the biological subject. As we understand the use of medical illustration today, the Roman pictures would be said to contain plenty of visual subjects without any adequate attention towards key points and lost in vast canvas.
Ancient Greece: Greek culture was described by mysticism and superstition, and illustrations related to medical sciences were less exact than the sciences; however there was an attempt to organize the diagram and give importance to a key subject. As time progressed, the Greek art pushed ahead of medicine by its own virtue. The artists attracted by the human form and their art forms did not reproduce previous non-scientific ones. They struggled meticulously to create the scientific form. In their mission to portray the exact human form, they were extremely conscious of body proportions. Undoubtedly, the Greeks contributed to medical illustration most because of the detail of topography.
Other than Hippocrates (c. 460 BC – c. 370 BC), the father of Western Medicine, the Greek philosopher Aulus Cornelius Celsus of the 2nd century, contributed immensely to the development of medicine and wrote most notable books on anatomical, surgical and pathological subjects, esp. De Re Medecina. It is a presentation of therapeutic suggestions for common diseases and is illustrated with plates. Celsus’s academic successor Galen of Pergamon (AD 129–c. 200/c. 216), a prominent Roman (of Greek ethnicity) philosopher, was arguably the most accomplished medical researchers of Antiquity period who contributed greatly to understand numerous medical disciplines, including anatomy, physiology, pathology, pharmacology and neurology based on his anatomical observations on animal dissections, but mostly in a descriptive way.
Medieval Europe: After the decline of Roman Empire, with the advent of Christianity and subsequently the Church’s domination on medical research based on the stress on the soul rather than the body, medical studies in Europe were still to be taught exclusively on the basis of Galen’s text until the 14th Century. Medical texts from medieval Europe are notably disinterested in the observation of human anatomy and inclined to repeat mindlessly the prototypes established in Galen’s text, accompanied by illustrations of the Roman scholar himself.  (Here, is an excellent LINK about 10 Bizarre Medieval Medical Practices)
We do not find any authentic anatomical illustration depicting diseases until the Renaissance, when both medicine and art had a glorious rebirth. – Maingot
The Great Renaissance: The artists of 15th Century Europe began to reject the authority of Galen and rediscover the classical traditions of Greek art as evidenced by the works of Leonardo da Vinci (1452-1519), Michelangelo (1475-1564) and Raphael (1483-1520), who performed dissections to study the human anatomy that created milestones in the history of art as well as medicine. During this period art, in general, was a mixture of realism and idealism and medical illustration was no exception. But it is important to note, that they were interested in the study of proportion for artistic ends rather than in anatomy for its own sake. Nevertheless, Leonardo was able to combine techniques familiar to him from architecture and engineering in order to represent the human body as recognizable, ‘three-dimensional’ figures. The physician or anatomist of this period had a titanic job on his hands to find an accomplished artist who would undertake to work on cadavers. One must remember that there were no preservatives used, and it was, therefore, a mammoth task on the part of the dissector to convince an artist to devote time to the anatomical material.
It is Leonardo da Vinci, who is still considered as the most influential artist in terms of the development of medical illustration, but Andries van Wezel (commonly known as
Andreas Vesalius, 1514-1564), the physician of Duchy of Brabant, did the most notable work in the history of human anatomy, thus medical illustration and probably Leonardo’s groundbreaking visual works cleared his way. His revolutionary work De humani corporis fabrica (‘On the Fabric of the Human Body’, 7 volumes, 1543) was the first complete and systematic description of the human body produced in modern Europe. It is the first true atlas of human anatomy. Vesalius stated that the 670 pages of text were secondary to the 186 visual plates, created by the illustrators of that period, which were accurate in their reflection and aesthetically outstanding. It was Vesalius who first realized that if certain artistic holdings should be skillfully discarded, the greater scientific value could be achieved in the illustrations. In Vesalius’ work, we discovered the economy of method and composition ideally adapted to the field.
Post-Renaissance: The great post-Renaissance advancement was made possible by lithography. The German, French, and English texts of this period are attractive stuff to understand the progression. Many of the illustrations are not too attractively illustrated but are painstakingly done. An in-depth examination of these plates in some of these books cannot help leaving the onlooker with great respect for the illustrator. One of the major influences on the progress of medical illustrations was also the introduction of Printer. The trio (physician, illustrator, and printer) was endeavoring to get the medical education in books of the higher caliber for the medical students.
The most notable name in this period was Max Brödel (1870-1941), a German illustrator, stands as the father of modern medical illustrations. In the late 1890s, he was brought to the Johns Hopkins School of Medicine in Baltimore to illustrate for Harvey Cushing, William Halsted, Howard Kelly, and other notable clinicians. His half-tone drawings had the authenticity of a photograph and His pen drawings no longer looked like etchings. He also created new techniques, like carbon dust, that were especially suitable to his subject matter and resolved many printer-publisher practical problems. In 1911, he founded the academic department of medical illustration situated in John Hopkins School of Medicine (now known as John Hopkins Medicine) and still regarded as Brödel-Hopkins School. (For more information about Max Brödel, visit this LINK)
Both Visual Arts and Medical fraternities of India probably never showed any interest in this field. In my past several years of exploration in the field of medical and scientific photography/imaging, I did not find any medical illustration contributed to the field of medicine except one forgotten artist from India. Wellcome Images, one of the world’s richest collection of medical and social history, achieved a couple of watercolor paintings by Behari Lal Das at around 1906 at Calcutta. There is no further information available about (probably) India’s first medical illustrator anywhere.
Today, in abroad, the aspiring illustrators complete a three-year course of study, much of it is tied in with the medical course. No longer is the physician grateful to a landscape painter for illustrating the unfamiliar subject of viscera or restrict him to the microscopic detail of some strange bit of tissue. Just as physicians specialize, so have many illustrators, notably Brodel for gynecology, William P. Didusch (1895-1981) for the urology, and Schlossberg for the heart. Now a day, authors in the western world can obtain illustrations prepared by a professional illustrator, obtained training from the heirs of the Brödel-Hopkins school. The horizons of medical illustration, including all forms of medical communication, are wide and fascinating, thus literally opened the new dimension of bio-communication, research, and documentation.
The introduction and development of Medical and Scientific Photography/Imaging nowadays make the complicated task easier taking much lesser time, yet the importance of illustration in medical science, especially in biomedical communication, cannot be ignored.
 Ollerenshaw R. Medical Illustration (The Impact of Photography on Its History); Journal of Biological Photographic Association, 1968; 36/1: 3
 History of science in classical antiquity: http://en.wikipedia.org/wiki/History_of_science_in_classical_antiquity
 Journal of Visual Communication in Medicine, 1986, Vol. 9, No. 2 : Pages 44-49