Anatomists say the human body is still being remapped

Human anatomy remains an active field of discovery, despite centuries of dissection and medical teaching, according to Michelle Spear, professor of anatomy at the University of Bristol. Spear wrote in The Conversation that the issue reaches beyond textbooks because anatomical variation can affect surgery, diagnosis, imaging and disease risk.

The modern sense that the body has been fully catalogued rests on a long history of influential anatomy books. Spear pointed to Andreas Vesalius’s 1543 work, De Humani Corporis Fabrica, which challenged inherited ideas from the ancient physician Galen by relying on direct observation of dissected human bodies. Three centuries later, Henry Gray’s Gray’s Anatomy helped fix the impression that the body had been neatly described and organized.

That confidence can be misleading, Spear wrote. Anatomy textbooks often present a standard human body for teaching, while real bodies vary by sex, age, population history, genetics, environment and individual development.

Old anatomy had narrow foundations

Spear said some of the classical anatomical record was built under conditions that limited what early anatomists could see. Much early topographical anatomy depended on cadavers obtained by grave robbers known as resurrectionists, who often targeted poor people, institutionalized people and those whose families could not protect burial sites.

The bodies available to early anatomists were not a broad sample of humanity, according to Spear. They often came with little demographic information, and many were affected by disease, malnutrition or post-mortem change. Women’s bodies were sometimes dissected, she wrote, but were less often reported in the anatomical record.

Spear emphasized that those limits do not erase the technical skill of early anatomists. They do mean that the “normal” body described in classical anatomy emerged from a restricted and socially unequal set of cadavers.

Variation is becoming central

By the 20th century, Spear wrote, anatomical investigation slowed as many researchers and educators treated the body as already mapped. By the 1960s, relatively few cadaveric studies were being published worldwide, and medical education often focused on passing on established anatomy rather than testing it with new observations.

That has begun to change, according to Spear. Improved medical imaging, renewed cadaver research and greater attention to anatomical differences between people have pushed scientists to re-examine structures and patterns that were once overlooked or poorly described.

Examples include lymphatic vessels around the brain that were not previously recognized and ligaments in the knee that have drawn renewed study, Spear wrote. She said familiar tissues are also being interpreted in new ways as researchers look more closely at individual variation.

The differences can be clinically significant. Spear wrote that blood vessels may take different paths, muscles may be missing or duplicated, and brain folding patterns vary from person to person. Differences in nerves, vessels and joints can influence symptoms, scan interpretation, movement and injury patterns.

Spear also linked anatomical variation to disease risk. Subtle differences in joint alignment may affect the risk of osteoarthritis, while variation in blood vessel anatomy can influence susceptibility to stroke or aneurysm, she wrote.

The broader lesson, according to Spear, is that textbook anatomy should be treated as a teaching model rather than a complete representation of biological reality. As researchers apply newer tools and study more varied bodies, the human map continues to change.

This story draws on original reporting from ScienceDaily.