The nervous system was particularly difficult for me to learn. Among other things, nerve pathways cross and crisscross at specific places in the brain and spinal cord. When the pathways are disrupted-from disease, stabbing, gunshot wounds-the whole system can be short-circuited. It took a leap of faith for me to understand that a gunshot wound that completely pulverized one section of the brain might leave the victim alive but severely disabled, while another gunshot wound that cut cleanly through the brain stem meant instant death as the diaphragm and heart quit forever.

Although at the time I was merely learning the architecture of the human interior in order to draw it accurately, one day this training would be vital for my work in forensics. Years later, while testifying in a murder trial, I became recognized as a court-qualified expert in gross anatomy as well as forensic anthropology-a rare distinction for a forensic anthropologist, and one I could not have achieved without my early studies at the Medical College. The case in question hinged on a minuscule cut in the victim's neck bone no bigger than an eyelash. I was able to prove that the tiny trace mark indicated a fatal knife wound when I demonstrated that in order to reach the bone in question, the killer's knife had to work its way through the victim's windpipe, esophagus, and a critical group of arteries, nerves, and veins.

Those nerves and blood vessels sure caused me enough trouble as a student! When I'd first looked at Dad's textbooks, I'd seen that each body part was rendered in a different color-red for arteries, yellow for nerves, and blue for veins. In real life, though, the colors seemed blurred and dulled, and all I could see were bunches of vessels, tangled together like three incredibly long varieties of overcooked pasta.

Gradually, I got used to the lack of color, and I learned to work by touch as well as by sight. When I could see the organs for myself and follow their contours with my hands, I could memorize their anatomy through my fingertips as the shape and location of even the tiniest lymph node flowed effortlessly from my hands into my brain.

In the anatomy lab, I had the luxury of being able to take bodies apart, piece by piece, to see exactly what made things work. Making my cadaver's fingers wiggle and her knees bend by pulling on a tendon imitated a muscle contraction. It might make this dead woman look like a macabre life-size marionette, but it taught me more than any textbook ever could.

The wonder of those first few months stays with me to this day. I walked around in a perpetual state of awe, amazed at the infinite variety of us humans and our bodies, even as I marveled at how alike we all are. I found myself looking at the crowds of people in the local shopping mall, people of different ages, races, and sizes, thrilled at my new knowledge that each anatomical structure shared a common shape, location, and function. Touch the inside of a wrist-anybody's wrist-and you'll feel the pulse of the radial artery in the same tiny spot… every time… in every body. This “human design element” is what makes modern forensic science possible-the fact that we know so much about any individual body before we've ever seen it.

Gross anatomy class was also where I learned that you must never-never-discuss “the bodies” in front of outsiders. You never knew who might be acquainted with the person whose body you were discussing, or who might accidentally overhear the conversation. What if your casual joking was heard by someone whose father had donated his body to science? How might the listener feel hearing you and your fellow med students blowing off steam by making derisive remarks about one of your cadavers? I'm grateful for the lesson now, since the same rule applies to forensic investigations: You talk about them only with fellow investigators. I think that's one reason why cops and forensic specialists maintain such a closed society. Only among our own can a case be discussed openly and freely, without fear of inadvertently wounding a grieving friend or family member.

This was also when I first encountered the peculiar balancing act that is the hallmark of my profession: Dead bodies are treated as objects to be probed for clues-and yet they must also be viewed as the living human beings they once had been, humans whom we try to honor by learning who they were and how they died. When I first started working in forensic anthropology, I'd approach each case like a puzzle, and I spoke only of “the body” or “the bones.” When I finally learned to refer instead to “the dead person” or “the human remains,” I was better able to hold on to my sense of each victim's humanity. Out in the field, it's easy to get wrapped up in the act of searching for bones, teeth, and evidence associated with the victim-jewelry, clothing, maybe a bullet-and it's all too common to find yourself shouting gleefully when someone finds one of these “treasures.” Among cops and other forensic specialists, it probably doesn't matter too much, but the effect can be devastating when civilians are looking on. I've learned to make a habit of acting as if the victim's mother were always looking over my shoulder and treating every piece of tissue, every scrap of evidence, as if I had a personal connection to the victim.

This approach really paid off when I was working with the remains of the people who died in the World Trade Center. Then, my every move really was under scrutiny by dozens of people, often including the victims' friends, families, and fellow firefighters or police officers. I was thankful, then, that I'd learned to treat every human remain with the respect it deserved, and I was moved by how much my colleagues in the morgue appreciated my gentleness and care.

As I continued with my medical illustration class, I was most fascinated observing surgical procedures. The medical illustration program at the Medical College of Georgia is considered one of the best in the nation, and one thing that makes it so special are classes in surgical observation, where students get to sketch actual operations while standing at the surgeon's elbow.

Writing these words today, I'm struck by how different my first surgical experience was from those of students today, who have access to television and movies that depict surgery in relatively realistic ways. The closest I'd ever gotten to an operating room before I observed my first surgery was TV's Ben Casey and Marcus Welby, M.D. In true 1970s television style, I imagined surgery as taking place in cathedral silence, amidst an atmosphere of high seriousness, with reverent doctors and obedient nurses clad in spotless white coats and immaculately clean rubber gloves. I simply had no idea of how bloody surgery can be and how raucous the process is, with music played by many doctors, and banter and cross-talk among the staff.

When I walked into my first operation, I was surprised to see the entire patient covered with the sterile sheets known as surgical drapes. Only the relatively small area that comprised the surgical field-the part of the body on which surgeons were operating-was exposed. With the patient's face, arms, and legs all blocked from view, I found it remarkably easy to forget that this procedure involved an actual human being, especially since the only people monitoring the patient's responses were the anesthesiologist and his or her nurses. During my first few surgeries, I was periodically startled out of my concentration on the procedure whenever the surgeon asked the anesthesiologist, “How's our patient doing?”

The most surprising aspect of my first surgery was the smell of burning flesh. This particular surgeon cut into his patient with a scalpel, then immediately burned the bleeding edges of the wound with a tiny cauterizing tool. Over the years, I've tried to describe the smell of burning flesh and the closest I can come is freshly burned toast thrown into a skillet already simmering with rotten fish, pork fat, and an old leather shoe. However, even that description may not do justice to the aroma. All I can say is that anyone who has ever experienced it recognizes it instantly. It's not like the smell of a fresh steak slapped on a grill: The odor of roasting human flesh is nauseating, pure and simple. And the sound of that cautery knife was horrible. I had to stop myself from jumping each time the surgeon touched it to the patient's flesh. Every time the knife hit the end of a bleeding blood vessel, I heard a little ssst, like the sound when you put a match into water. Ssst… and a fresh burst of the smell… a tiny tendril of smoke, rising into the air.