As a child growing up in Rhode Island, Devon Nykaza was a science buff. But in her free time, she also enjoyed drawing.

"I was sort of confused, because you're told that these are such divergent areas," said Nykaza, 26.

When she was 15, she found her calling in a high school science textbook.

"I opened up a textbook and thought, 'Someone has to do these illustrations -- why can't it be me?' " Nykaza said.

She is now a graduate student at Johns Hopkins University's Department of Art as Applied to Medicine and is training to be a medical illustrator, someone who draws human anatomy, plants, animals and surgical procedures. One day, her drawings could be used in science journals, magazines, textbooks and advertisements.

On Friday, Nykaza and her five classmates visited the Naturalist Center in Leesburg, where they sketched some of the center's 36,000 specimens. The center, an extension of the Smithsonian's National Museum of Natural History, houses one-of-a-kind animal, plant and mineral specimens. They include dried starfish, bird skins, a bald eagle and two polar bears.

A mounted atlas beetle caught the eye of Lydia Gregg, 22, who is from Michigan. Between quick pencil strokes, Gregg explained what drew her to medical illustrating.

"It's the urge to tell an idea through a piece," she said, eyeing her subject methodically. "You want to communicate something through art."

The students' completed drawings will be loaned to the Naturalist Center, where they are likely to be part of an exhibit on careers in medical illustrating, said David Rini, an associate professor at Johns Hopkins. The sketches will be placed alongside the original specimens so visitors can see the artists' interpretations.

Medical illustrating is all about precision work -- having a fine eye for detail and being able to grasp complex scientific processes, Rini said. At the same time, having an artistic eye is crucial.

"These are people who love science, love medicine and are gifted artists," Rini said. "And they want to combine the two."

During their two-year master's degree program, Rini's students will take classes in science and art. On some days, they will study biology and animal anatomy -- basically completing the first year of medical school. Other days, they will practice airbrushing and digital techniques.

To hone their craft, they will sketch cadavers. In their second year, they will sit in on brain, heart and eye surgeries and draw what they observe.

Rini said a graduate degree is the best way to break into the small, selective field. There are about 1,000 medical illustrators in the United States and most have undergraduate degrees in biology or pre-medicine. Some have joint degrees in art and science.

Johns Hopkins accepts six out of 80 applicants a year for its program, which was founded in 1911 and is the oldest in the world, the university says. Only four other accredited graduate programs in that discipline exist in North America, and most were founded by Johns Hopkins graduates, Rini said. The other programs are at the University of Illinois at Chicago, the Medical College of Georgia, the University of Texas at Dallas and the University of Toronto.

After graduation, many students work for medical research institutions such as the Cleveland Clinic, where their illustrations are used in journals and research publications. Others illustrate textbooks or work as medical legal illustrators, providing evidence in court.

Several of Rini's students have pursued careers in three-dimensional computer animation, providing illustrative material for pharmaceutical companies in advertisements and digital presentations.

The average starting salary for a medical illustrator is $40,000 to $45,000 a year, according to the Association of Medical Illustrators. Experienced illustrators can earn up to $75,000.

Being successful means having the ability to explain science through illustration.

"There are scientific artists and artistic scientists," Rini said, but "the first purpose is to teach."

Lydia Gregg, above, a graduate student in Johns Hopkins University's Department of Art as Applied to Medicine, is aiming for a career as a medical illustrator. She refines her craft at the Smithsonian's Naturalist Center in Leesburg. At left, David Rini, an associate professor at Johns Hopkins, sketches a mounted eagle.

Johns Hopkins graduate student Lydia Gregg's sketch of a beetle takes shape at the Naturalist Center in Leesburg.

At the Smithsonian's Naturalist Center, Duc Nguyen photographs a cat he intends to sketch. He is in training to become a medical illustrator.