Fifth period, on a recent Thursday, began with a discussion of the often-maligned, seldom-seen impacted wisdom tooth.

	Bob Donaldson, Post-Gazette Hampton Senior High School anatomy teacher Bob Palmer, here with senior Nikki Howell, uses a computer program called "Adam" to teach his popular anatomy course. Click photo for larger image. Listen In Hampton teacher Bob Palmer discusses a human skull with his class.

Bob Palmer held up a $1,000 model of the human skull and pointed out the offender, sideways in the jaw.

"This is true to scale, true to size," Mr. Palmer told 23 seniors at Hampton High School. "See how it's jammed inside?"

Aspiring dentists may have noted Mr. Palmer's aside: "Not a lot of room to work there."

In more ways than one, as they peek behind skin and bone, the students in Mr. Palmer's anatomy and physiology course get to see what they're made of.

The popular, high-level elective draws overachievers, average students and stragglers. All are welcome. Few leave disappointed.

The course offers intensive use of medical school-quality software and a chance for the top 16 to observe open heart surgery at Allegheny General Hospital.

Students have been known to enroll in the class, grades weighted at 5.0, to put meat on their transcripts. Others want to see what the buzz is about or experience a Hampton rite of passage.

"They don't want to graduate and be the senior who didn't have Bob Palmer," principal Jeff Finch said.

Some alumni, inspired by Mr. Palmer, have gone on to health careers.

"He totally influenced me to be who I am," said Dr. Jonathan Bickel, a third-year pediatric resident at Children's Hospital and 1996 Hampton grad. Other students have benefitted from the organizational skills Mr. Palmer instilled or relished the atmosphere of collegial inquiry in Mr. Palmer's classroom.

"It was really interactive and productive," Dan Brager, a Cornell University student and 2005 Hampton graduate, said of class discussion.

When Mr. Palmer took over the class in 1989, he taught two sections a day, for juniors and seniors, and spent the rest of his time teaching psychology. Now, he teaches only seniors, and only anatomy, seven sections of it daily, a heavier workload than required by contract.

This year, Mr. Palmer has 143 students--about half of the Class of 2007. He agreed to teach a seventh section this year so no senior would be turned away. His prerequisites: biology, chemistry and a willingness to apply oneself.

"I teach to the valedictorian," said Mr. Palmer, 60, who has a bachelor's degree from Edinboro University of Pennsylvania and a master's degree from Duquesne University.

Senioritis isn't an observable condition in Mr. Palmer's classroom. Other ailments dominate the discussion.

"How many people get sinus headaches?" asked Mr. Palmer. With an image of the skull projected onto a screen, he explained how bacteria or viruses invade the sinus cavities.

During the hour-long period, Mr. Palmer appeared to have the students' undivided attention. Nobody talked out of turn, checked a cell phone or waved to friends in the hallway.

"He made the material come alive," Dr. Bickel recalled.

Like the body, Mr. Palmer's course is organized for efficiency.

He begins the school year with an overview of terminology and the organizational techniques students need to stay on top of material.

Students must save diagrams and notes in a particular kind of three-ring binder. If the school doesn't have enough binders, Mr. Palmer will buy them for students, Mr. Finch said.

Students explore class topics with A.D.A.M., interactive anatomy and physiology software that functions, in part, as a virtual cadaver. The program allows users to cut through layers of skin, bone and muscle with successive clicks of the mouse.

Some of Mr. Palmer's prouder moments have been watching struggling students rise to the challenge. Sometimes, they find the wherewithal inside themselves; other times, they're buoyed by collaboration with higher-performing peers.

"I will work hard not to let a kid drop the course," Mr. Palmer said. He said he tells worried students, "Just let me guide you."

For one exam, students must memorize 360 terms. They must stop at stations around the classroom to identify bones. They must know each bone's place and function.

Spelling counts.

Mr. Palmer is still learning, too. He subscribes to the New England Journal of Medicine. He reads about advances in medicine so he can answer students' questions.

"I have to deliver what they're coming through the door to get," he said.