Nothing Is “Normal”? Expect Variation

Why we keep rethinking human variation, representation, and the language of A&P

What does a normal human body look like?

Uh-oh.

That question gets complicated pretty quickly. Is “normal” what is most common? What is average? What falls within some expected range? What is healthy? What looks like the illustration in an anatomy textbook?

Those aren't necessarily the same thing. And that matters when we're telling students the story of the human body.

Variation isn't an exception to the story

Back in 2021, I wrote about our long-running effort toward Diverse Representation in Anatomy & Physiology.

That work goes back several editions, but it kicked into much higher gear during the revision of the 10th and 11th editions. We looked hard at who appeared in our photos and illustrations, whose bodies were represented in our examples, and how our language described the varied humans our students will eventually encounter in healthcare, fitness, wellness, and other professions.

Then we kept going in the 12th edition. Because variation isn't an exception to human anatomy and physiology. Variation is human anatomy and physiology.

I've been thinking aloud about this for years. In The A&P Professor (TAPP) Episode 43, Anatomic Variations in Humans, I wondered whether “normal” anatomy is partly a useful—or maybe even mythical—construct. We need some representative model when we begin teaching anatomy. But no actual human being perfectly matches every feature of that model. The A&P Professor

Age and development change us. Genes vary. Embryological events vary. Hormones vary. Nutrition, activity, environment, injury, disease, and lived experience all contribute to what our bodies look like and how they function. Even genetically identical twins develop differences.

So perhaps the real story of human anatomy is not uniformity.

It's unity with variation.

Then there's that word: “normal”

During the 11th-edition revision, the Patton Team did something rather tedious.

We reconsidered every instance of the words normal and abnormal.

I later shared that project during the 2023 HAPS Annual Conference workshop Editing A&P Textbooks Through a DEI Lens: Authors' Perspectives.

Why fuss over two perfectly ordinary words? Because when we stopped and asked what we meant by normal, we often discovered that we meant something more precise: typical, average, expected, within a reference range, or perhaps simply healthy.

Those aren't synonyms.

Research examining the concept of normality in medicine makes essentially the same point. Normal can refer to statistical typicality, health, desirable function, an ideal, or other concepts depending on context. Mixing those meanings can create confusion.

And abnormal can be even trickier. Being statistically unusual doesn't necessarily mean unhealthy. Being outside an average doesn't necessarily mean pathological.

Yet normal and abnormal carry everyday meanings that can quietly slide from common versus uncommon into good versus bad—or even acceptable versus unacceptable.

Usually, that's not what we're trying to say in an A&P textbook.

So we counted them

Here's what happened when we deliberately reconsidered those terms.

Edition	“Normal”	“Abnormal”	Combined
10th	743	341	1,084
11th	91	68	159
12th	82	54	136

Most of that dramatic shift occurred during the 11th-edition revision. But we didn't declare victory and move on.

The 12th edition gave us another opportunity to make a careful second pass—not only at normal and abnormal, but at many other words, images, examples, and explanations related to human variation.

That graph makes the change rather hard to miss.

And then something interesting happened

Here's a bit of evidence we didn't have when we began this work.

In 2026, researchers published a study specifically examining how anatomical variation is described in anatomy textbooks. They found that abnormal was used more often than more neutral descriptors, including in some contexts involving common or asymptomatic variations. Their recommendation was to teach anatomical variation explicitly and use neutral, prevalence-aware terminology rather than automatically framing variation as defective or pathological.

Well.

That sounds familiar.

I don't mean that as “See? We were right!” Science and teaching are rarely that tidy. But I do find it reassuring that an independent analysis published after much of our revision work identifies essentially the same problem we had already been wrestling with.

This wasn't a search-and-destroy mission

We didn't ban the words normal and abnormal. Sometimes one of them really is the clearest word.

The point was to stop using either one automatically.

If we mean average, say average. If we mean typical, say typical. If we mean disease, say disease. And if we mean outside the expected reference range, perhaps that's what we should say.

A nice example occurs in our homeostasis chapter. For the 12th edition, a figure label changed from setpoint value to setpoint range, and an area previously labeled abnormal became disease. We also added explicit arrows representing physiological fluctuation.

That's more than swapping one fashionable word for another.

It's more accurate physiology.

“Typical” doesn't mean everybody

We use typical fairly often now when we need a representative starting point.

That distinction matters. A textbook has to teach general patterns. We can't introduce every possible variation every time we introduce a structure, so we may begin with the typical structure of something.

But typical isn't meant to imply the only proper version.

In Chapter 1, for example, we clarified the continuum of variation among sex characteristics and added explicit discussion that even twins exhibit anatomical variation. 

That reflects something I discussed in TAPP Episode 43: teaching often has to begin somewhere near the middle of a spectrum. Then we help students discover the variation around that starting point.

The representative model is the beginning of the story—not the boundary of reality.

What students see matters, too

Words were only part of this project. We also continued revising the visual story.

The 12th-edition revision notes describe this as an ongoing effort to replace some classic illustrations with a broader spectrum of variation among human subjects. That helps more students see themselves represented, but it also prepares future health professionals to encounter more of the variation they'll see in real people. 

That effort shows up throughout the book. Muscle figures were revised to show more varied skin colors and additional examples of human variation. Elsewhere, figures were revised for varied skin tone, hair color and style, and even a subject with a leg prosthesis. 

We've updated cases, names, and other details, too. Individually, those changes may seem small. Taken together, they change the population students encounter as they move through the book.

In short, we kept asking not only What do we say? but also What do students see?

Both matter.

Anatomy education still has some catching up to do

There's growing evidence that this is not a trivial concern.

A 2026 analysis of contemporary anatomical education resources found continuing imbalances in sex and skin-tone representation across major anatomy textbooks and digital resources. The study wasn't an analysis of undergraduate A&P survey texts, so I don't want to stretch its findings beyond what it examined. But it reinforces the larger point: the anatomical bodies students repeatedly see help establish their mental picture of what a human body looks like.

And illustrations aren't merely decoration. They're part of the teaching.

If nearly every body a student sees looks essentially the same, that's a lesson.

Maybe not the lesson we intended—but still a lesson.

Why does this matter?

There's an inclusion argument, of course. I've made it before.

Students should be able to see themselves as belonging in the population we're studying and in the health professions they're preparing to enter. That's one reason I discussed reflecting diversity and using inclusive language in TAPP Episode 108, The Inclusive Anatomy & Physiology Course.

But there's also a straightforward A&P argument.

We are supposed to be teaching students about human bodies.

Actual human bodies vary.

Students preparing for health professions need to know that. A healthcare professional who has unconsciously learned that one idealized body represents “normal anatomy” and everything else is a deviation from it has learned an incomplete version of anatomy.

So has an athletic trainer. So has a fitness professional. So has anyone whose work involves understanding real human structure and function.

What does “normal” mean, anyway?

I wrestled with that question directly in TAPP Episode 101, Even MORE Test Answers | Normal Body Temperature?.

Body temperature makes a great example. Even something as familiar as “normal body temperature” varies among people, across the day, with measurement site, under different physiological circumstances, and across populations and historical periods.

A mean can still be useful. A reference range can still be useful. A representative pattern can still be useful.

We don't have to abandon any of those.

We just have to remember what they are: models of reality, not definitions of who counts as a proper human being.

Another pass. And then another.

One thing I've learned from this process is that inclusive and accurate representation isn't a box we can check.

DONE!

Nope.

Language changes. Science changes. Our awareness changes. Sometimes we discover that wording we thought was perfectly clear carries an implication we never intended. Sometimes new research reveals variation we weren't even aware of. And sometimes somebody simply points out something we've been staring at for years without seeing it.

That's why the major push in the 11th edition wasn't the end of this effort. We made another rigorous pass in the 12th edition. The official revision notes explicitly describe bias-aware language and varied representation as continuing, research-informed processes rather than finished projects.

And I'm sure there will be more to fix.

There always is.

Expect variation

A&P works because human bodies share remarkable patterns.

That's the unity part.

But those patterns occur across an equally remarkable range of individual differences.

That's the variation part.

Students need both.

So perhaps the most useful lesson isn't that this structure, measurement, or body is normal.

Maybe it's this:

Here's the pattern. Here's the range.

And expect variation.

If you don't have your own copy to review, please request a free instructor review copy of the new 12th Edition of Anatomy & Physiology.

Lost in the Chapter? Why A&P Students Get Two Outlines

How chapter outlines and summaries help A&P students build a conceptual framework

Learning anatomy and physiology isn't simply a matter of collecting facts. Somehow, students have to organize all those facts into a coherent structure.

That's a big somehow.

Learning researchers sometimes describe this process as structure building—constructing a mental representation that connects incoming information into an organized whole. Some readers are better at doing that on their own. Others have more difficulty figuring out which ideas are foundational, how the pieces fit together, and which details belong where.

That seems especially important in A&P. We're asking beginning students to make sense of an enormous number of unfamiliar structures, processes, relationships, and terms—often all at once.

A textbook can either help them build that structure or make them figure it out entirely on their own.

I'd rather help.

Structure isn't just decoration

There's some interesting evidence behind this idea.

Research with college students has found that differences in structure-building skill are associated with differences in remembering facts, making inferences, solving problems, and learning from complex educational text.

Even more interesting, a 2025 study manipulated the coherence of a textbook chapter by removing structural signals—including topic headings, boldface terms, and take-home boxes. Readers with stronger structure-building skills managed pretty well either way. Readers with lower structure-building skills did significantly worse when those signals were removed.

In other words, some students can build the map themselves.

Others benefit when we put up some road signs.

Research on headings points in the same direction. Headings can help readers identify a text's topic structure, remember how ideas are organized, and comprehend what they're reading.

This is one reason we've put so much thought into the structure of each chapter of Anatomy & Physiology.

Two—count 'em, TWO—chapter outlines

Each chapter actually has two outlines.

That may sound like overkill.

It's not.

At the beginning of every chapter is a very brief Chapter Outline. Very brief. It's essentially an indented list of the first- and second-level section headings that the reader is about to encounter.

An embedded Hint encourages students to skim this outline before beginning the chapter. I've written before about why we include these embedded reading hints throughout the book.

Think of that first Chapter Outline as a conceptual blueprint.

Or maybe it's like looking at the acts and scenes listed in a play's program before the curtain goes up. You don't know the story yet, but you have some idea where it's headed.

You know the major locations.

You know when the story is moving from one part to another.

And you have a framework ready when the details start arriving.

Then we tell the story

As readers move through the chapter, they encounter those same section headings again.

That's intentional.

The headings aren't simply labels breaking up gray blocks of text. They remind the reader, Oh yeah. This is where I am in the story.

That may seem pretty ordinary to those of us who are experienced textbook readers. We automatically look at headings. We recognize hierarchies. We anticipate where the discussion is going. We know that a new heading means we're shifting to another branch of the conceptual tree.

Beginning students may not do any of that automatically.

In fact, recent research on headings found that they can support not only comprehension, but also students' ability to judge how well they understand what they've read.

That's a nice bonus. Knowing that you don't understand something yet is a pretty important step toward learning it.

Then we tell them what we told them

At the end of each chapter comes the second outline—the Chapter Summary.

This one is much more robust.

It follows the same basic structure students first saw in the opening Chapter Outline and then encountered in the headings throughout the chapter. But now the outline is filled in with the important concepts and relationships from the chapter.

It's the story again—this time compressed.

As I write this, I'm reminded of something my instructor told us in my first college writing course:

Tell them what you're going to tell them, tell them, then tell them what you told them.

It's good advice for expository writing.

Turns out, it's not a bad strategy for helping students learn A&P, either.

The opening Chapter Outline tells readers where they're going.

The headings keep reminding them where they are.

The Chapter Summary lets them look back at where they've been—and see how the pieces fit together

An outline isn't magic

I don't want to oversell this.

Simply putting an outline in front of a student doesn't magically build a coherent mental model.

One study examining outlines during learning found that skeletal outlines improved recall for students with lower structure-building ability, but didn't by themselves improve deeper explanatory understanding.

That's important.

It's also why I like the combination of learning aids in our chapters.

There isn't just a Chapter Outline. There are section headings, illustrations, tables, Quick CHECK questions, Hints, Big Picture connections, and then the Chapter Summary.

Research on embedded questions is especially interesting here. In a study using a textbook chapter, embedded questions improved performance among readers with lower structure-building ability and helped them form more coherent representations of what they had read.

We've long used those kinds of cues throughout our chapters.

The goal isn't to do the thinking for students.

It's to give them enough structure that they can do the thinking themselves.

Terry took a fresh look at every chapter

Of course, outlines evolve along with chapters.

As we revised chapters over successive editions, we tweaked their summaries to keep them aligned with the changing narrative. Perfectly reasonable.

But after enough rounds of tweaking, little inconsistencies and awkward spots can accumulate.

For the 12th edition of Anatomy & Physiology, Terry Thompson took the lead in reviewing and revising the Chapter Summary outlines across the entire book.

Rather than simply patching individual outlines, Terry looked carefully at their clarity, conciseness, style, and flow.

The result is a more consistent set of Chapter Summaries across the book. They're also somewhat shorter. That helped us make room for updated content while contributing to our larger effort to make this edition shorter overall.

Our revision notes describe the goal pretty well: the summaries were streamlined to make them more useful for PREVIEW and REVIEW.

Preview and review.

Which brings me to something I think we sometimes forget.

The Chapter Summary isn't only for the end

Students can use the detailed Chapter Summary before reading the chapter.

Really.

For a reader who tends to get lost in dense scientific material, previewing that expanded outline can reveal the conceptual structure before the details start flying.

Then the student reads the chapter with somewhere to put those details.

And afterward, the same outline becomes a review tool.

That's also why I've long encouraged students to look over a chapter before they read it—skim the headings, notice the major terms, and look at the illustrations before diving into the narrative.

It's a simple textbook-reading strategy, but students may never think to do it unless somebody tells them.

But don't stop at rereading the summary

There's another step I'd add.

The Chapter Summary works best when it becomes a tool for active review rather than something students simply reread over and over.

Retrieval practice has one of the strongest evidence bases in learning science. Trying to recall information strengthens later learning better than simply restudying it.

So I encourage students to use the summary as a check on their own mental framework.

Look at a heading and try to explain what's underneath it before reading the summary points.

Cover part of the outline and reconstruct it from memory.

Turn a summary point into a question.

Sketch the relationships as a concept map.

Then look back and see what you missed.

Now the Chapter Summary isn't merely summarizing.

It's helping the student build—and test—the structure in their own mind.

I've been harping on retrieval practice and concept mapping for years for exactly this reason.

Tell students why it's there

There's one more ingredient that I think matters.

Transparency.

I've made the case elsewhere that students do better when we stop hiding how a course—or a learning tool—is supposed to work.

We shouldn't assume that students know what to do with a Chapter Outline just because we've put one there.

Tell them.

"Before you read, take a minute and look through this outline. You're building a mental framework for what comes next. As you read, notice how the section headings match that framework. When you finish, use the Chapter Summary to see whether the structure you built matches the structure of the chapter."

That's not remedial advice.

That's teaching students how to learn from a science textbook.

In fact, in Six More Textbook Tricks, I made the case that we faculty rarely talk explicitly with our students about how to use a textbook effectively. We probably should.

A map through a complicated story

A&P is complicated.

There's no getting around that.

But complicated doesn't have to mean disorganized.

A brief outline before the story, clear structural signals along the way, and a fuller outline afterward give readers repeated opportunities to see how the pieces fit.

For some students, those cues may reinforce a framework they would have built anyway.

For others, they may be the difference between seeing a coherent story and seeing a giant pile of anatomy and physiology facts.

Either way, I think it's worth giving them the map.

If you'd like to check out this chapter format yourself, request a free instructor review copy of the new 12th Edition of Anatomy & Physiology.

Fascia: Following the Connections

Why this body-wide story keeps growing in Anatomy & Physiology

Fascia is having a moment.

Actually, it's been having a pretty long moment.

Research into fascia has expanded greatly in recent decades, along with interest among anatomists, physiologists, physical therapists, massage therapists, movement specialists, pain researchers, surgeons, and others.

What was once too easily dismissed as the stuff you cut through—or remove—to get to the "real" anatomy is increasingly being studied as an important participant in the structure and function of the body.

Which means fascia deserves appropriate attention in an undergraduate A&P course.

We've thought that for quite a while.

Base image: Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body. Bartleby.com: Gray's Anatomy, Plate 384, Public Domain, https://commons.wikimedia.org/w/index.php?curid=561537

We've been going deep with fascia

Deep. Get it?

Okay, moving on.

Our coverage of fascia in Anatomy & Physiology didn't suddenly appear in the 12th edition. We've been giving fascia significant attention since the early 1990s, and nearly every edition since then has reflected our expanding understanding of what fascia is and what it does.

Even then, we were asking students to think beyond individual muscles and isolated structures. We pointed out structural and functional relationships among the cytoskeleton inside cells, the extracellular matrix outside cells, and the myofascial structures of the body.

In other words, the little pieces fit into bigger pieces—and those bigger pieces remain connected.

By the 2010 edition, released in 2009, we had also incorporated Thomas Myers's Anatomy Trains concept. Myers developed this model during the 1990s as a way of teaching "connected anatomy." It proposes that muscles and fascia form myofascial continuities, or functional "trains," that can help us think about whole-body posture and movement.

Later anatomical research has found support for several of the proposed myofascial continuities, although not all of them. Their functional significance and the amount of force that may be transmitted along them remain active areas of investigation.

That's an important distinction.

We don't include an interesting model because it settles the science. We include it when it can help students think about the science—including the parts we're still figuring out.

Wait. Is there really a "fascial system"?

You'll notice that in the new edition we sometimes use the term fascial system.

Not everyone likes that term.

And I don't mean that somebody complained about it on social media. There's a genuine scientific and anatomical terminology debate going on.

The Fascia Nomenclature Committee of the Fascia Research Society developed two related definitions. A fascia refers more narrowly to a dissectible sheet, sheath, or aggregation of connective tissue. The fascial system is a broader concept describing a three-dimensional continuum of collagen-containing connective tissues that permeates the body. The broader term is particularly useful when considering the functional relationships among these tissues rather than viewing each named fascia in isolation.

Some researchers want to go further. A 2025 paper in the Journal of Anatomy formally proposed that fasciae and their interstitial components constitute an anatomical system—a body-wide, multiscale network with superficial, musculoskeletal, visceral, and neural components.

Case closed?

Of course not.

A 2026 paper in Clinical Anatomy argues specifically that fascia should not be classified as an anatomical system, particularly within the framework of bormal international anatomical terminology.

So why did we use fascial system in the textbook?

Because we find it to be a useful functional and teaching concept.

We're not announcing the discovery of an additional organ system or claiming that fascial system has become universally accepted anatomical terminology. We're using a term found in the scientific literature that helps students recognize something important: these connective tissues have extensive relationships throughout the body, and many of those relationships make more sense when we don't consider each bit of fascia in isolation.

As the science and the terminology evolve, our usage may evolve, too.

That's what textbooks are supposed to do.

Why should A&P students care?

Because our understanding of fascia has moved far beyond its old reputation as passive wrapping material.

Research is investigating fascia's roles in mechanical force transmission, movement, proprioception, nociception, tissue remodeling, fluid relationships, and pathological processes.

Consider innervation. A systematic review found that fasciae are well innervated, with different types and densities of nerve endings in different fascial tissues. Those include proprioceptive and nociceptive endings, with some evidence of increased innervation in pathological fascia.

That's pretty important information for somebody learning how the body senses itself, moves, and experiences pain.

It's increasingly important clinically, too.

Students heading into physical therapy, massage therapy, athletic training, rehabilitation, sports medicine, and other health professions are likely to encounter fascia again. Some forms of manual therapy and rehabilitation explicitly target fascial tissues or use fascial models to help explain assessment and treatment.

That doesn't mean every proposed fascial mechanism—or every treatment marketed as "fascial"—has been established.

Far from it.

The evidence varies, and research continues.

To me, that's another argument for teaching the basic science appropriately.

Our students need enough anatomy and physiology to understand—and eventually evaluate—the clinical claims they'll encounter.

Fascia is becoming an A&P teaching issue, too

This isn't only a conversation among fascia researchers and clinicians.

It's increasingly a conversation among anatomy and physiology educators.

Rebecca Pratt made an especially useful argument about this several years ago. How do we squeeze an increasingly complex understanding of fascia into an already packed health-sciences curriculum?

Her answer was essentially: put it where it belongs. Everywhere.

Because fascia itself is found throughout the body, Pratt argued that it can be integrated throughout an existing curriculum rather than requiring another isolated block of material. Her article puts it nicely: fascia can fit anywhere in the curriculum because it is found everywhere.

That sounds awfully familiar.

More recently, my colleague and former student Dr. Kate Oland has become something of a fascia advocate among A&P teachers, encouraging us to give fascia the emphasis it deserves in our courses.

Kate Oland and me at a recent HAPS Conference in Pittsburgh PA.

Kate and I explored many of these ideas in Episode 152 of The A&P Professor podcast, Fascinating Fascia: Kate Oland Unravels the Ties That Bind. We talked about the traditional tendency to rip fascia out of the way during dissection, the increasingly connected view of fascia, clinical applications, and why fascia deserves more attention in undergraduate A&P.

Then, at the 2026 HAPS Annual Conference, fascia showed up prominently on the program.

Dr. Alan Detton presented an Update Seminar, Fascia, What Is It and Why Should I Care? HAPS described his presentation as addressing the meaning of the anatomical term fascia and its significance in A&P.

And Kate presented a workshop with a title that gets right to the issue: The Fascial System: A Missing Link in A&P Education.

Two fascia presentations at one HAPS conference?

I'd say the conversation has arrived.

Peggie keeps us connected

Which brings me back to the 12th edition of Anatomy & Physiology.

Author Peggie Williamson took the lead in implementing and coordinating much of our fascia-related work for this revision.

Peggie is our Patton Team fascia expert. Besides being an experienced A&P educator, she's a doctor of physical therapy who has worked directly with patients and now serves on the faculty of a Doctor of Physical Therapy program, helping prepare the next generation of physical therapists. Her clinical background includes myofascial release and other approaches to soft-tissue treatment.

That gives her a particularly valuable perspective for this topic. She understands what beginning A&P students need, but she also knows where those basic concepts may eventually lead in clinical education and practice.

So when Peggie tells the rest of us that we need to take another look at something involving fascia, we take another look.

More fascia in the 12th edition

What did that mean for this edition of Anatomy & Physiology?

In Chapter 9, Tissue Types, we added a completely new Connect It! article, Fascia: The Body's Not-So-Hidden Network.

I like that title because fascia really isn't hidden.

It's everywhere.

As anyone who has spent much time in a traditional dissection lab knows, however, fascia is often dissected away so that muscles, nerves, vessels, and organs can be seen more clearly.

That's understandable.

But it can also leave students with the unintended impression that fascia is something obscuring the anatomy rather than something that is part of the anatomy.

In Chapter 10, Skin, we've added an explicit connection between the hypodermis and the fascial system.

And in Chapter 15, Axial Muscles, we've added further explanation of fascia to an illustration, along with clarification of related connective-tissue structures.

Those may sound like relatively modest changes when they're listed one at a time.

But they're additions to fascia coverage that was already distributed through several parts of the book.

That's intentional.

Why isn't there a fascia chapter?

If fascia is increasingly important, why don't we simply put it all together in one chapter?

Maybe someday we will.

We've done that sort of thing before.

Over the long history of Anatomy & Physiology, topics that were once scattered through several chapters have sometimes developed enough—and become important enough—that we've brought them together into a more unified story. Homeostasis, stress, and the lymphatic system have all evolved substantially in our book over the years.

Most recently, we gathered much of our distributed coverage of the human microbiome into the new Chapter 49.

Could fascia eventually get similar treatment?

Maybe.

But fascia presents an interesting teaching problem.

Its connections to other structures are part of the story.

When students are learning connective tissues, fascia belongs there.

When they're learning about the hypodermis, fascia belongs there.

When they're studying skeletal muscles, muscle compartments, and movement, fascia belongs there.

And when we're asking students to connect what happens inside cells with the extracellular matrix outside them—and then follow those relationships into tissues and larger body structures—we're building another part of the same story.

That's why, at least for now, we think its reappearance at pivotal points is one of the clearest ways to teach fascia.

Besides, repeated encounters let students keep adding to their mental model.

They don't learn "fascia" once and put it away.

It keeps coming back.

Sort of like fascia.

Ahead of the curve?

I'd like to think we've been a bit ahead of the curve.

Not because we've somehow known in advance where fascia research would lead.

We haven't.

Some ideas about fascia have changed. Others remain unsettled. Some claims will undoubtedly be revised or discarded as the evidence improves.

What I think we got right fairly early was taking fascia seriously.

We didn't treat it simply as disposable packing material surrounding the structures that really matter. We emphasized relationships among cells, extracellular matrix, fascia, and muscle. We introduced students to body-wide myofascial relationships. And as the science expanded, we kept revisiting the story.

Now we're seeing researchers working toward broader models of fascia, clinicians applying fascial concepts in practice, and A&P educators asking whether fascia has been getting enough attention in our courses.

So we're not scrambling to insert an unfamiliar topic into the textbook.

We're continuing a story we've been telling—and revising—for decades.

One chapter someday?

Maybe fascia eventually deserves a chapter of its own.

Or maybe not.

There is something pedagogically satisfying about meeting fascia again and again as we work our way through tissues, skin, muscles, movement, and other parts of the A&P story.

After all, its repeated appearance is part of the point.

The structures and functions of the human body don't operate in isolation.

Fascia keeps reminding us of that.

And we'll keep watching the research—and listening to instructors, students, clinicians, and researchers—to see where this story takes us next.

What?! You don't have a free examination copy to review? Please request a free instructor review copy of the new 12th Edition of Anatomy & Physiology.

What's Up with Eponyms in A&P? Part 3

Keep them? Dump them? Or learn to live in the messy middle?

Way back in 2018, I discussed various issues with using eponyms—terms derived from a person's name—in Part 1 and Part 2 of this article series.

Among those issues are whether to use the possessive or nonpossessive form, when to capitalize the term, and some of the historical and social baggage that can come along with certain eponyms. 

At the end of Part 2, I promised that Part 3 was "coming up in my next blog post."

That was in August 2018.

Apparently, next is a fairly elastic concept.

I wrote about half of this post back then, set it aside, and forgot about it. My recent post, Say It. Take It Apart. Learn It., describing our global terminology update for the 12th Edition of Anatomy & Physiology, reminded me that I never finished this part of the story.

So, eight years later, here we are.

This time I want to tackle what may be the hardest eponym question of all:

Which term should we actually teach?

When both an eponym and a descriptive term are in common use, which should be our primary term? Which one gets relegated to secondary status? And when should we simply stop mentioning the eponym at all?

Turns out, that's not an easy question.

Snippet from the Brief Atlas and Quick Guide to the Language of Science and Medicine that accompanies Anatomy & Physiology. If you cannot see the image click here.

It's not really a yes-or-no choice

As we prepared the 12th Edition of Anatomy & Physiology, the Patton Team revisited this issue.

Was this finally the edition in which we should ditch eponyms altogether?

Should we continue using them sparingly, as we had been doing?

Or had we moved too far, too fast, and ought to restore more of the familiar eponyms our students are likely to hear in clinical settings?

Another of our lively Patton Team discussions followed.

There was shouting. Punches were thrown.

Okay, no.

But people did have opinions.

We considered what would best help beginning A&P students, what terminology they're likely to encounter in later courses and healthcare careers, what's happening in academic anatomy, and what's actually happening in clinical practice.

And I think we all came to appreciate something that should have been obvious from the beginning:

This isn't a simple binary choice.

There are reasonable arguments at both ends of the keep-'em-or-dump-'em spectrum.

Recent discussions among professional anatomists haven't resolved that tension, either. A 2024 survey of editors of major anatomy journals found that respondents generally preferred Latin- and Greek-derived terminology when communicating with students and other anatomists, yet many also considered eponyms acceptable in publications and useful in discussing the history and ethics of anatomy.

In other words, even the terminology people are living in the messy middle.

That made us feel a little better.

Anatomy gives us a pretty good roadmap

For anatomical structures, our decision was relatively straightforward.

The International Federation of Associations of Anatomists (IFAA) maintains the FIPAT anatomical terminologies, including Terminologia Anatomica, Terminologia Histologica, Terminologia Embryologica, and Terminologia Neuroanatomica. These provide international standards for the anatomical sciences.

For more than a century, formal anatomical nomenclature has been moving away from eponyms as the official names of structures.

The current Terminologia Anatomica 2 takes a nuanced approach. Its official terms are standardized and noneponymous, but familiar eponyms and other unofficial names can still appear as related terms.

Sound familiar?

That's pretty close to where we landed.

For anatomical structures, our general rule is to use the descriptive term as the primary term. We'll mention a familiar eponym as a secondary alternative only when we think knowing it will genuinely help the student.

So pancreatic islets wins over Langerhans islets.

Uterine tube wins over fallopian tube.

We aren't pretending the older terms never existed. We're simply giving the descriptive term priority.

There are several advantages.

A descriptive term often tells a student something useful about the structure. Pancreatic islets at least tells me where to start looking for them. Islets of Langerhans tells me that somebody named Langerhans is involved in the story.

And yes, I still really enjoy saying islets of Langerhans.

But enjoyment isn't much of a pedagogical argument.

But won't our students hear the eponyms?

Absolutely.

That's one of the strongest arguments for continuing to mention at least some of them.

Clinical terminology changes slowly. Many healthcare professionals learned eponyms and have used them for decades. Some will continue using them regardless of what an international terminology committee recommends.

And accuracy in healthcare communication matters.

So students living through this transition need some degree of terminology bilingualism. They should know the preferred descriptive term, but they also need to recognize important older names when they encounter them.

That's different, though, from asking beginning students to memorize two names for everything.

We discussed that possibility, too.

Sure, knowing every traditional eponym alongside every descriptive term could be useful. Knowing Norwegian would be useful, too. Our students would be exceptionally well prepared to give their acceptance speeches when they win a Nobel Prize.

There's another eponym for you.

But an A&P course already asks beginning learners to master an enormous vocabulary. Adding a second name wherever a familiar eponym survives would increase an already enormous terminology load. That doesn't strike us as a good tradeoff—especially because the descriptive term is often more informative.

If a student later enters a setting where a particular eponym is still routinely used, learning one additional synonym is not an extraordinary burden.

We all do that constantly in ordinary language.

Meanwhile, we can model preferred descriptive terminology for students, help them understand why professional language changes, and perhaps help them learn how to appropriately advocate for clearer terminology in their future professional environments.

That's how languages evolve.

Some eponyms aren't ready to leave

Then there are eponyms for which we don't have a satisfactory, widely used replacement.

Golgi apparatus is an obvious example.

It's unquestionably an eponym. But what are we going to call it instead?

Dictyosome sometimes gets offered as an alternative, but that's not a clean substitution. Current biological terminology uses dictyosome as a synonym for a Golgi stack, which is a component of the larger Golgi apparatus.

So Golgi stays.

For now.

That's another reason a rigid "no eponyms" rule doesn't work very well in a real A&P textbook.

Terminology has to be usable.

Physiology makes everything messier

Once we move from anatomy into physiology, the eponym question gets considerably harder.

Unlike human anatomy, physiology does not appear to have a single internationally recognized, comprehensive terminology comparable to Terminologia Anatomica.

At least, we have not been able to identify one.

There are authoritative terminology and nomenclature systems for many of the sciences that feed into physiology. The International Union of Pure and Applied Chemistry—IUPAC—maintains extensive international recommendations for chemical nomenclature and terminology.

For physical quantities and units, we have internationally standardized systems such as the International System of Units (SI).

And we use those authoritative resources when revising Anatomy & Physiology.

But none of them gives us a comprehensive answer to questions such as:

What should we call every physiological process?

Every physiological relationship?

Every effect, response, test, or clinical method that students encounter?

That's where things get dicier.

Consider the Bohr effect, named for physiologist Christian Bohr, for example. It's an eponym for a physiological relationship deeply embedded in the language of respiratory physiology.

Or consider the Apgar score, named for Virginia Apgar. That's an eponym for a clinical assessment our health professions students may encounter.

There's no comprehensive descriptive-terminology list we can consult that says, "Here is the approved replacement."

Sometimes the eponym simply is the term currently used by the scientific and clinical community.

Science itself is full of eponyms

And then there are the terms we borrow from chemistry and physics.

Try teaching introductory A&P without using volt, joule, hertz, or degree Celsius.

Those names commemorate Alessandro Volta, James Prescott Joule, Heinrich Hertz, and Anders Celsius.

They're eponyms.

They're also internationally standardized units.

In fact, the SI rules preserve that history in an interesting way. The spelled-out unit names volt, joule, and hertz are lowercase ordinary nouns, while their symbols V, J, and Hz are capitalized because the units were derived from personal names. Celsius retains its capital letter in degree Celsius because it remains a proper name.

So much for simply banning every term derived from a person's name.

Science is full of them.

So what did we decide?

After years of gradually reducing our reliance on eponyms—and another round of lively discussion for the 12th Edition—we arrived at a pretty simple working policy.

Avoid eponyms as primary terms whenever a well-established descriptive term is available.

Use eponyms sparingly as secondary terms when knowing them is likely to help students.

Accept that we're stuck with some eponyms until scientific and clinical terminology evolves.

Simple policy.

Messy implementation.

Because every individual term still requires judgment.

How well established is the descriptive alternative?

How widely is it currently used?

Will students encounter the eponym frequently enough that failing to mention it would put them at a disadvantage?

Is the descriptive alternative truly equivalent?

Does an authoritative terminology or nomenclature source weigh in?

And, sometimes, has the history attached to an eponym given us another good reason to move away from it?

Those decisions can require more digging than you might expect.

The language keeps moving

One thing I'm more certain about now than I was when I started writing this series in 2018 is that anatomical terminology isn't finished.

It never will be.

Even Terminologia Anatomica continues to evolve. There are active debates among anatomists about which terms should be official, which alternatives should be retained, how clinical terminology should be accommodated, and whether some attempts at standardization have gone too far—or not far enough.

A particularly interesting collection of recent discussions in Anatomical Science International shows just how lively these disagreements remain.

So we're not trying to freeze the language of A&P at some supposedly perfect moment.

We're trying to give beginning learners the terminology that will serve them best now, while preparing them to recognize that the language will continue changing throughout their careers.

That's why our choices in Anatomy & Physiology will keep changing, too.

And that's where you come in.

If you have thoughts about our approach to eponyms—or about a particular term you think we've gotten right, wrong, or somewhere in between—please let us know.

Authors and editors can research terminology.

But thousands of A&P instructors, students, scientists, and clinicians are a pretty good early-warning system for changing usage.

Language evolves.

We need watchers.

If you want to be a watcher for us, please request a free instructor review copy of the new 12th Edition of Anatomy & Physiology.

Say It. Take It Apart. Learn It.

How we rebuilt the terminology tools in Anatomy & Physiology, 12th Edition.

An A&P course is partly a language course.

Okay, it's a huge language course.

Our students encounter hundreds of unfamiliar terms, many of them long, difficult to pronounce, and constructed from word parts they've never seen before. And we're asking students to learn all that new language while simultaneously learning some pretty challenging concepts.

That's why Anatomy & Physiology has long provided terminology-learning tools that you may not find—or may not find in the same depth—in other A&P textbooks.

For our new 12th Edition, we decided those tools deserved a major tune-up.

And that's how Frank got himself into trouble.

A word list with a job

At the beginning of each chapter, we provide a chapter word list.

It's comprehensive. The list gathers all the boldface terms from the chapter narrative, along with an occasional italicized term when we think it's useful to include it.

That gives students one convenient place to preview the important language of the chapter.

But these aren't intended simply as "vocabulary words that might be on the test."

I've previously explained the idea in Word Lists Help Students Build Their Mental Lexicons.

One useful way to prepare for reading an A&P chapter is to scan its terminology before digging into the narrative. That gives the reader a chance to start becoming familiar with the words before trying to understand the concepts they represent.

Learning research gives us good reason to think about new vocabulary this way. Becoming familiar with a word involves developing connections among how the word is written, how it sounds, and what it means.

That's one reason I don't want students meeting carbaminohemoglobin cold in the middle of an already complicated explanation of blood-gas transport.

Give the poor student a fighting chance.

Say it

Our chapter word lists include a simple phonetic pronunciation guide for each term, along with an embedded hint instructing the reader how to use it.

The comprehensive Glossary does, too.

That lets students practice saying a term before encountering it within a sentence that's already asking them to understand some new anatomical or physiological idea.

Yes, I actually encourage students to say the terms aloud.

I've been beating that drum for years—in Word Lists Help Students Build Their Mental Lexicons, in The A&P Professor podcast Episode 20, Reading A&P Terms Out Loud Helps Reading Comprehension, and again in Episode 145, A Tongue Twister's Guide to Mastering Anatomy Pronunciation.

There is learning science behind my nagging.

Research on what's called the production effect has repeatedly found that saying words aloud can improve later memory for them compared with simply reading them silently. One leading explanation is that producing the word makes its memory more distinctive.

Does that mean saying carbaminohemoglobin three times will suddenly make you understand blood-gas transport?

Nope.

But the term can begin to "sound right" in the learner's mental lexicon. When it later appears in a sentence, the reader has one less completely unfamiliar thing to wrestle with while trying to understand the actual A&P.

That can be especially helpful for readers who aren't yet very comfortable predicting the pronunciation of unfamiliar English words.

Which, when you think about English pronunciation, could be just about anybody.

Why not put the pronunciation right in the sentence?

Some textbooks put pronunciation guides immediately after a term the first time it appears in the narrative.

There's an obvious advantage to that: the pronunciation is sitting right there when the reader needs it.

But we chose a different approach.

A beginning A&P learner is already trying to hold unfamiliar structures, processes, relationships, and vocabulary in mind while making sense of a sentence. Dropping a phonetic pronunciation guide into the middle adds another piece to process—and interrupts the flow of an explanation that may already be challenging.

We'd rather give students the pronunciation before they read.

And if they need it again, it's waiting in the chapter word list or Glossary.

I should be clear that I don't know of research directly comparing our approach with inline pronunciation guides in A&P textbooks. That's our application of what we know about reading, vocabulary learning, memory, cognitive load, and our experience watching beginning A&P students wrestle with unfamiliar terminology.

Take it apart

Pronunciation is only part of the job.

Most A&P instructors I know are constantly taking terms apart for their students.

Hyper- means above.

Hypo- means below.

Cardi- refers to the heart.

-itis means inflammation.

We do this almost without thinking.

Why?

Because once students start recognizing commonly used roots, prefixes, and suffixes, an intimidating scientific term becomes a lot less intimidating.

Our chapter word lists support that approach by showing useful word parts and their basic translations. Students can skim them while previewing a chapter.

Our Glossary provides those same kinds of clues when students look up terms later.

I've discussed this strategy before in Word Parts Help Students Master the Language of Science and Handy Supplement Helps Students Master the Lingo of A&P.

Word parts can act as little mnemonic clues. They may help students remember the spelling and meaning of a term.

More importantly, each familiar word part becomes another tool students can carry forward. When they encounter a term they've never seen before, they can often begin taking it apart and making an educated guess about what it means.

That's a skill they'll keep using in later courses and eventually in clinical settings.

And isn't that exactly what we A&P professors already do?

We point out word parts during lectures and discussions. We explain them in handouts and assignments. We keep reminding students that this bit means one thing and that bit means another.

The difference is that our chapter word lists give students a complete, consistent resource that's always handy.

Research on morphological learning—learning to recognize and use meaningful word parts—supports its usefulness in building vocabulary. A 2023 study with college learners, for example, found that explicit morphological training improved receptive academic vocabulary learning. The National Library of Medicine likewise teaches medical terminology by having learners identify prefixes, roots, suffixes, and other components and use them to work out meanings of unfamiliar medical terms.

Anatomy-specific research has also found benefits from explicitly teaching Latin and Greek etymologies alongside anatomical terminology

No, learning a pile of Greek and Latin roots isn't a magic shortcut to mastering A&P. Research with undergraduate A&P students has found only a weak relationship between their existing knowledge of Greek and Latin roots and overall course performance.

That's fine.

We're not trying to turn the chapter word lists into a Latin course.

We're giving students another tool for figuring things out.

Names change, too

Another part of our terminology cleanup involved continuing a transition we've been making for years: moving farther away from eponyms as our preferred anatomical terms.

An eponym names something after a person. Islets of Langerhans, haversian canal, and fallopian tube are familiar examples.

Eponyms remain deeply embedded in clinical language, and our students are going to encounter many of them. So we don't pretend they don't exist.

But international efforts to standardize anatomical terminology have long favored standardized descriptive terminology rather than eponyms as the preferred names for structures. Clinical usage has not always moved at the same speed.

So our general approach is practical: teach students the currently preferred descriptive terminology while helping them recognize important alternate terms they'll still hear and read elsewhere.

I've written about some of this before in What's Up with Eponyms in A&P? Part 1 and What's Up with Eponyms in A&P? Part 2.

And yes, at the end of Part 2 I promised a Part 3.

In 2018.

I really ought to get back to that.

Especially because A&P faculty still have some pretty lively disagreements over what we should do with eponyms. We had a few of those discussions within the Patton Team, too.

Or what passes for lively disagreement among us.

More about that another time.

Then Frank got the job

All of this sounds fairly straightforward until you realize how many terms we're talking about.

And how many pieces each entry has.

Which term should be preferred?

Which alternate terms should remain?

Is the pronunciation accurate?

Is it consistent with similar terms elsewhere in the book?

Are the syllables and word parts divided appropriately?

Are their translations useful to a beginning learner?

Does the formatting make the entry easier to understand?

Now multiply that by an entire A&P textbook.

Then remember that our revision team included four authors, at least three editors, and a collection of reviewers, copyeditors, proofreaders, compositors, and others.

Having all of us independently "fix" terminology seemed like an excellent recipe for making it less consistent.

Clearly, we needed one person to wrangle the whole thing.

Author Frank Bell, our in-house terminology guru, seemed like the obvious choice.

I vaguely recall that Frank was absent from the weekly Patton Team meeting when his name came up as the perfect person for the job.

Pure coincidence, I'm sure.

When the news reached him, Frank didn't hesitate.

Much.

A global terminology cleanup

Frank took on a global review of the terminology resources for the entire book.

And it turned out to be a much bigger job than any of us anticipated.

Besides reviewing the terminology itself against current usage and authoritative sources, he went through the pronunciation guides, word parts, translations, and formatting.

Occasionally, Frank would come back to me with a question such as, "Why did you do it this way?"

That's always a fun question for an author who has been revising a textbook for decades.

Sometimes I could explain the original thinking.

Sometimes the answer was probably some variation of, "Well, I'm sure there was a reason."

With that background, Frank could decide whether the original approach still made sense—or whether he had found a better one.

Once Frank completed his review, the other authors incorporated his terminology changes throughout the chapters and other elements being revised.

Then editors checked us.

Then copyeditors checked us.

Then proofreaders checked us.

And, as always, despite all that checking, I'm sure somebody will eventually find something we missed. That's what happens in a project containing thousands upon thousands of tiny details.

But this is by far the most systematic and consistent terminology review we've ever done.

And there's the Glossary

As I mentioned in the first post of this series, The A&P Textbook You May Have Overlooked, we've moved our large Glossary from the back of the printed textbook to the Evolve Student Resources.

That helped us make the physical book noticeably shorter without taking this resource away from students.

The Glossary is more comprehensive than the chapter word lists. It includes all the boldface and italicized terms from the text narrative, plus some additional terms that students encounter only in figures or tables.

And it reinforces the same learning tools students encounter in the chapter word lists.

How do I say this term?

What useful word parts can I recognize?

What do those parts mean?

So a student can preview terminology in the chapter word list, encounter it while learning the chapter's A&P, and return to it later in the Glossary.

Same language. Same system. Same tools.

Our best terminology tools yet

When Frank finally emerged from beneath the mountain of terminology, the 12th Edition had the most carefully reviewed and internally consistent collection of A&P terms, simple pronunciations, and useful word-part translations we've ever produced.

Having looked at the terminology resources available in the other A&P textbooks we examined, I suppose I could claim that ours is the best A&P terminology collection in the universe.

I'm not going to claim that.

But I think I could.

What I will claim is that we worked very hard to make these resources accurate, consistent, easy to use, and genuinely useful to beginning A&P learners.

Terminology isn't something we add around the edges of an A&P course.

It's the language students need to learn the course.

So we think it's worth getting the words right.

If you'd like to explore these terminology resources yourself, request a free instructor review copy of the new 12th Edition of Anatomy & Physiology.

The Ovary Is Not a Conveyor Belt

Rethinking how we tell one of the trickiest stories in reproductive A&P.

In my previous post, Why We Flipped the Reproductive Story, I explained why we reorganized three chapters in the new 12th Edition of Anatomy & Physiology.

But reorganizing chapters was only the beginning.

Once we started taking apart our traditional reproductive story and putting it back together, we found ourselves looking much more closely at some familiar explanations and illustrations.

One of the biggest examples was the ovary.

The ovary is harder than it looks

The basic story seems straightforward enough.

Ovarian follicles develop. An oocyte is released at ovulation. The remaining follicular tissue becomes a corpus luteum. If pregnancy does not occur, the corpus luteum degenerates. Meanwhile, hormonal changes help regulate the whole process.

Simple, right?

Well, not really.

The more closely we looked at how introductory A&P textbooks—including our own previous editions—portray this story, the more we wrestled with a basic problem:

How do we make ovarian structure and function simple enough for a beginning learner without making it so simple that we teach something misleading?

That's always a challenge in A&P.

We aren't trying to prepare our students to become reproductive biologists during one chapter of an introductory course. But we don't want the simplified story they learn now to become something they'll have to unlearn later, either.

A cycle isn't a straight line

One particular problem is the cyclical nature of ovarian function.

Textbook illustrations necessarily arrange developmental stages in some kind of sequence so students can follow them. That's useful. But a sequence laid out from left to right can begin to look like a conveyor belt.

One follicle progresses to the next stage, then the next, then ovulation happens, and then comes the corpus luteum.

Except an ovary doesn't really work like a factory assembly line.

Follicles at different stages can be present at the same time. Most do not proceed all the way through the sequence. And the whole process operates within recurring ovarian and menstrual cycles regulated by changing physiological conditions.

So one of our goals was to preserve a clear developmental sequence while making the cyclical nature of ovarian function easier to see.

That's harder than simply drawing a circle instead of a line.

Simple, but not too simple

We spent a lot of time discussing what a beginning A&P student actually needs to know about ovarian follicles.

How many developmental stages do we name?

Which structural changes really matter for understanding function?

How much histological detail helps the story, and when does added detail start obscuring it?

What terminology best prepares students for what they'll encounter in later courses?

And how closely can an introductory illustration resemble actual ovarian structure while still functioning as an explanatory diagram?

Those questions generated considerably more discussion than you might expect from looking at the finished pages.

Yeah. We can talk about follicles for a surprisingly long time.

Our goal was not to include everything that's currently known. Our goal was to identify the structural and functional ideas that give beginning students a sturdy conceptual framework.

Then they can keep building on it.

Some terminology changed, too

Rethinking the story also meant looking carefully at the words we use to tell it.

For example, the new edition introduces vesicular ovarian follicle in place of the older term graafian follicle in our chapter-opening vocabulary. That change also aligns with our ongoing quest to deemphasize the use of eponyms.

We've also made terms such as oocyte, menstrual cycle, and menstrual phase more visible in the reproductive story.

These aren't simply vocabulary swaps.

Terminology affects how students organize concepts in their minds. If we're asking them to understand ovarian function as part of recurring reproductive cycles and as part of changes across the life span, the vocabulary should support that framework.

Menopause belongs in the larger story

We also took a fresh look at our coverage of menopause.

In Chapter 46, we now introduce perimenopause and postmenopause and describe what happens during each stage. These terms are becoming increasingly familiar to patients and are showing up more often in conversations with their healthcare providers. We think our health professions students should begin building that framework in A&P.

Menopause, after all, isn't simply the point when menstrual cycles stop. It belongs to a broader physiological story involving changing ovarian function, reproductive hormones, and effects that extend beyond the genital system.

So we refined the discussion in Chapter 46: Reproduction and coordinated it with the broader life-cycle coverage in Chapter 47: Growth, Development, & Aging.

That's another advantage of our new organization.

Chapter 46 can establish the reproductive physiology—including perimenopause, menopause, and postmenopause. Chapter 47 can then revisit those changes within the larger context of aging.

Same concept. Different perspective.

You may recognize a familiar theme here: students build stronger conceptual frameworks when important ideas show up again in meaningful new contexts.

Textbook illustrations are arguments

I've often said that an illustration in an A&P textbook isn't merely decoration.

It's part of the narrative.

In some ways, every anatomical illustration makes an argument about what students should notice, what they should connect, and what they should remember.

That became especially obvious as we worked on the ovary.

We wanted our revised presentation to say, visually as well as verbally:

This is a dynamic organ. These processes are cyclical. The stages are related, but they are not simply beads moving along a string.

And, as always, this is the beginning of the story—not the last word on ovarian biology.

Take a look

When you receive your review copy of the new 12th Edition, spend a few minutes with Chapters 45 and 46 and compare our new ovarian story with the one you remember from earlier editions—or with the way you currently explain it to your students.

I'd be interested to know whether you think we've found the right balance between clarity, accuracy, and just enough detail.

If you haven't already requested a free instructor review copy of the new edition, click here and do that now.