Mark Manning knows his body well. In fact, if you were to take your index finger (gloved, of course) and insert it into his rectum, he would be able to tell you exactly when your fingertip is pressing against his prostate, a male reproductive gland that is said to be slightly larger than an unshelled walnut. And if you were to cup your hand around one of his testes, he could guide you toward his epididymis, an elusive piece of male anatomy that he describes as feeling like “a macaroni noodle, half-cooked” in an endearing Georgia drawl.

Like most people who are well-versed in a particular field, Manning knows these things because it is his job to know them. As a male urogenital teaching associate, or MUTA in medical shorthand, the 58-year-old retired General Motors employee teaches the testicular and rectal exam to unseasoned medical students, using his own body as a live model. Employed by the Atlanta-based company, Clinical Skills USA, Manning and his colleagues (including female instructors called gynecological teaching associates, or GTAs) travel the country to lead aspiring doctors through reproductive exams—the pelvic and breast exams for women, and the rectal and testicular exams for men—which are notorious for being among the procedures most dreaded by the general public, second only to root canals and colonoscopies.

As MUTA, Manning estimates he’s had somewhere around 4,000 male urogenital exams throughout his nine years in the field, and oftentimes as many as eight per day when he’s on duty—most of those performed by nervous second-year medical or nursing students who’ve had very little, if any, interaction with living, breathing patients.

But that’s part of the point. As a clinical guinea pig, Manning’s job is to ease their anxiety and train them in the basics of these routine exams. He does this using humor: “Y’all, please check your nails. We had to trim one earlier. It was pretty long.” But he also mixes in practical, patient-friendly tips: “Make sure to turn your back to your patient while they’re wiping to give them that little moment of dignity.”

Manning coaches a second-year medical student as she practices the rectal exam during a visit to Rocky Vista College of Osteopathic Medicine in Lone Tree, Colorado. Shauna Intelisano

Manning also works to dispel a prevailing myth that has come to accompany reproductive exams over the years—namely that they’re often uncomfortable for the patient. One of the core principles of Clinical Skills USA’s teaching curriculum is that neither the male nor female exams should be remotely painful, or evenly highly uncomfortable, if performed properly. Any physician who does hurt a patient, they argue, has not been correctly trained, which is often the case for those who attended medical school prior to the ’90s.

Then, and still in many instances today, medical students learned and practiced reproductive exams using either simple plastic manikins or actual patients, with the guidance of a clinical instructor (“preceptor,” as they are referred to in the field). And for the female exams, some schools even hired prostitutes or used anesthetized women who were never given the opportunity to consent.

Today nearly every medical school uses standardized patients (essentially actors playing patients) for basic training, such as practicing doctor-patient encounters and diagnoses, but the use of the more specialized GTAs and MUTAs is much less prominent. In fact, just over half of the medical programs in the United States employ GTAs, and less than half employ MUTAs, since unabashed male teachers are especially difficult to recruit.

This was where Scott George saw an opportunity. After working as an independent MUTA for a few years, George founded Clinical Skills USA in 2004 to bring teaching associates to schools without their own in-house programs. George, now a strapping, handsome 61-year-old in the way of middle-aged men in Cialis advertisements, began by recruiting groups of MUTAs and GTAs for teaching sessions at schools in the Atlanta area, but quickly expanded to include programs around the county.

“The schools jumped right onto it,” he says on a recent trip to Rocky Vista University, a College of Osteopathic Medicine located just outside of Denver. “As my people were working more and more at these schools, they were developing a greater sense of self-confidence and acquiring more knowledge, and I suddenly had a commodity.”

Guiding patient Katie Patterson teaches the breast exam during a visit to Rocky Vista. Shauna Intelisano

His commodity, as it were, is what he prefers to call “guiding patients,” rather than MUTAs or GTAs, because it’s easier for him to recruit people using that term. It also works to highlight the advantages his employees bring to the exam table over other methods. Preceptor-led training is less than ideal since patients have no idea when to tell a student that they have correctly located their ovary or palpated their prostate with just enough force. And though manikins have become more technologically advanced, fitted with sensors to help students judge pressure and position, there’s no computerized response to communicate pain.

Clinical patients may also expect the exam to hurt and therefore fail to tell the student when it does, which again, fuels a potentially dangerous misconception. Studies have shown that fear of a negative experience can deter patients from going for routine physicals, which means serious ailments could go unchecked for years.

Guiding patients, on the other hand, can direct students to perform the exam comfortably and correctly because they know exactly what it should feel like. “We are teaching students to give patients a positive experience,” George says. His 25 employees also make it a priority to train students on how to treat their patients in a friendly and professional manner, which transcends reproductive exams to apply to all patient-doctor interactions.

“I am a customer service nut, and this is customer service where it’s needed most,” George says. “If you’re going to get people to come in and do what they should be doing, which is to regularly come in for well-men and well-women exams, then you have to do what you can to make the experience as un-daunting as possible. And that’s what we try to teach the students—to help their patients relax.”

Manning tells a story about "maintaining a sterile field" while teaching the testicular and rectal exams. Shauna Intelisano

They also try to teach the students to relax. Variations on the phrase, “Remember that we are not here to assess you, but to teach you,” are commonly repeated refrains, and nearly all of the guiding patients have a talent for making students laugh. The use of lame puns such as “bare with me” or anatomy jokes are welcome in this context—anything that helps break the ice between the student and the partially nude teacher standing before them. “We love laughter,” George says. “Laughter is great. It’s their way of easing their anxiety.”

Helping students overcome their apprehensions—about hurting someone, screwing up or otherwise—is an essential part of the job, because for many future doctors or nurses, this may be the only time they get to perfect the exam before conducting it in a clinical context.

At Rocky Vista, several of the GTAs calmly coach students through proper speculum insertion over and over again until they successfully locate the cervix. Or as Tim Cordier, a 51-year-old guiding patient and part-time bicycle tour guide, tells his students (sans pants and bent over a countertop in a stance he likens to a football player in the line of scrimmage), “If there’s anything you want to practice four or five times, then this is your chance.”

Standing exposed while several 20-somethings use your privates as test dummies is obviously not an easy job. It requires a religious level of patience, and guiding patients must endure numerous mishaps along the way, such as fainting students or their own bodily complications. Recently, Cordier’s doctor actually found a callus on the left side of his prostate, which he’s developed from enduring so much prodding.

“The non-glamorous part of this job is when you’re on your cycle,” adds Katie Patterson, a spunky 32-year-old guiding patient, insurance agent and mother of two. “But it is what it is. It’s medicine right? You have to be able to handle everything.”

A second-year medical student practices the breast exam with Patterson at Rocky Vista. Shauna Intelisano

All of the guiding patients are paid especially well for their time—to the tune of $35 to $50 per student for the 30 to 50 days they work each year—but as they will tell you, it’s impossible to do what they do unless you have the passion for it. As Patterson says, “It takes a certain kind of person to be able to teach these exams.”

As such, they are all refreshingly immodest, tolerant and open people, and because of this, they have grown very close over the years. They invite one another over for barbecues and go out for dinner and drinks, where they shamelessly talk a brand of shop that is almost entirely inappropriate for the dinner table.

“We’ve become a sort of family,” says Patterson. “This has created an unbreakable bond between so many of us, and I will probably do this until I can’t do it anymore.”

But despite their similarities, the group is as diverse as a “sort of family” comes: With ages ranging from 22 to 65, they are black and white, and among them are a Jehovah’s Witness, an energy healer, a retired teacher, a few actors and one singer-songwriter who plans on auditioning for The Voice in the next few weeks. When not in scrubs or in the nude, they wear everything from cowboy boots and Stetson hats to stilettos and silk blouses.

Guiding patients, from left: Tim Cordier, Katie Patterson, Lori Lambert, February Brown, Mark Manning, Elizabeth Marshall and founder Scott George. Shauna Intelisano

Their motivations for becoming guiding patients are also wide-ranging and often very personal, including close relatives who died of prostate cancer, sons who contracted testicular cancer, traumatizing experiences with painful pelvic exams and a professed fascination with the intricacies of the human body. One woman even joined the group in order to overcome the body issues she developed as a result of her strict religious upbringing, and Manning claims the job helped him to become more extroverted following his divorce.

This mixed bag of motives is also what helps them endure the stigma that all of them inevitably face, whether it stems from puritan-bred, American squeamishness or general immaturity when it comes to nudity.

“I’ve learned the hard way that you cannot be completely open about this line of work,” Patterson says after a full day of pelvic and breast exams at Rocky Vista. “I used to be—because I am not ashamed of my body, and I’m not ashamed of what I do—but there is an exorbitant amount of ignorant people in this world who do not have a mind that wraps around science or medicine, whatsoever. They look at it as more of a sexual, nasty, unprofessional thing to do. And it’s only because they’re ignorant.”

When he first started, Manning had a similar experience after a close friend of his likened the job to prostitution. “That was probably the hardest thing about this job,” he says. “Just trying to talk to people about it.”

Fortunately, he’s over that hump, as are most of his colleagues. They are remarkably dedicated to what they do and happy to count their bodies as instrumental teaching tools in the education of tens of thousands of American medical professionals.

And the students are happy they’re there, too. Almost all of those at Rocky Vista used the word “amazing” to describe the experience, and were baffled to learn that not all medical or nursing schools teach in such a “hands-on” way. “Students tell me that I’m a great teacher,” Manning says after prepping the lubricant, tissues and gloves for that day’s session. “That’s something no one else has ever said to me before.”