With rapt and reverent attention, more than 750,000 visitors in St. Paul gazed in awe five years ago at the exposed muscle, sinew and bone of preserved human bodies in graceful poses.

On Friday, a new "Body Worlds" exhibit opens at the Science Museum of Minnesota -- with a new message.

"I listened to what people were saying back then -- they wanted not only to appreciate how the body works, but to understand their diseases, the problems they experience with their own bodies in life," said Dr. Angelina Whalley, who designs "Body Worlds" exhibits.

In a way, the exhibit is an opportunity to practice preventive medicine, said Whalley by phone from the Institute for Plastination in Heidelberg, Germany. Her husband, Gunther von Hagens, founded the institute after developing the Plastination process in 1975. More than 35 million people have seen the various "Body Worlds" exhibits in 78 cities worldwide.

"Most laypeople have little understanding of their bodies, how they work, how they are constructed," she said. "When they learn more -- when they see how wonderful and amazing their body is -- they take better care of [themselves]."

While the new show illustrates a number of diseases, the larger focus is on how the body changes during a lifespan. People in their 20s begin to lose certain muscle power and elasticity. Eyes, hearts, lungs and other organs change with age and usage.

"To understand disease," Whalley said, "you really need to understand the cycle of life."

From embryos to old age

"Body Worlds & the Cycle of Life" examines the aging process with 20 full-size human cadavers in various poses, plus scores of smaller specimens.

The exhibit includes embryos and fetuses, a teenage skateboarder, a ballerina and a stooped man using a cane.

It also examines how cells, skin and organs change, including displays of lungs from a smoker and a nonsmoker. Visitors will see an illustration of the blurred and murky images that French impressionist painter Claude Monet -- suffering from cataracts -- likely saw for 10 years before he had surgery.

This is the second U.S. showing of the "Cycle of Life" exhibit, which debuted last year in Chicago. Other "Body Worlds" exhibits focus on the human heart, the brain, the body's potential and on animals.

The specimens are preserved through a process that replaces body fat and fluids first with an acetone solvent, then in a vacuum with a flexible polymer. The process can take several weeks.

Answering critics

Since the first "Body Worlds" exhibit in Tokyo in 1995, the shows have come under some criticism from people concerned about the origin of human specimens and whether the exhibit of human bodies is too titillating.

Much of that controversy has gone away, especially after California investigators proved that the adult displays came from among more than 9,000 people who had agreed while alive to donate their bodies for that purpose. Embryo and fetus displays came from collections held by universities and medical institutions.

But some hosts of the exhibit, including the Chicago Museum of Science and Industry, have cautioned that young children should be accompanied by adults, particularly when viewing the embryos and fetuses. The St. Paul museum will not issue that caution.

"Families or teachers, of course, should be with their children during the exhibit because children will have questions," Whalley said. Children, she added, are often amazed and curious about how their bodies grew from a small cluster of cells.

Whalley remembered a past "Body Worlds" exhibit, when she watched a child examine the lungs of a smoker, then turn to ask her father to stop smoking.

"Children understand very well the relationship between our lifestyles and our bodies," she said. "They are wonderful students, but also wonderful teachers."

Bodies bring the crowds

Science Museum officials said they expect about 350,000 visitors for the "Cycle of Life" show -- about half the turnout of the 2006 exhibit -- because it will run for 4 1/2 months instead of seven.

Whalley is in St. Paul this week to help set up the exhibit and attend the opening events. But already she is at work on a new "Body Worlds" show. She will not describe it until there is a public announcement, perhaps later this year.

"There are so many possibilities to help us better understand the human body," she said.

Warren Wolfe • 612-673-7253