Pelvic health physical therapist Hollis Herman famously said, “Vulvas are as different as
faces.” The same is true for penises, and for every structure that makes up the external
genitalia. Size, shape, color, symmetry, hair pattern, prominence, and proportion vary
widely from person to person. Labia may be long or short, tucked in or extending
outward; clitorises may be more or less visible; penises may curve, hang, or change
shape with arousal. Skin tones range from pink to beige to brown to deep brown,
sometimes with natural gradients of color. All of it is normal. All of it is healthy. All of it is
human variation. The real question is not whether this variation exists, but whether our
patients know this, and if they don’t, what that lack of knowledge is costing them in their
sexual health and well-being.
Sexual Anatomy Is Shared Anatomy
Biologically, male and female external genitalia are built from the same foundational
structures, with each part having a homologue in the other sex. The clitoris and the
penis, for example, are homologous organs, both are highly sensitive, erectile, multi-
chambered structures that fill with blood during arousal. The labia majora and the
scrotum are also homologous, made of soft, elastic, hair-bearing tissue, while the
clitoral hood and the foreskin serve the same protective role for highly sensitive tissue
beneath. Less commonly discussed but equally important, the posterior fourchette and
the frenulum are both densely innervated areas that play a significant role in sensation,
and Skene’s glands, often referred to as the female prostate, are homologous to the
male prostate. Similarly, Bartholin’s glands and Cowper’s glands serve parallel functions
by producing lubrication during sexual arousal. None of these structures exist because
of symbolism, modesty, or cultural meaning; they exist because of embryology and
function. Differences in appearance do not reflect differences in purpose—they simply
reflect different arrangements of the same biological parts.
Pleasure Is Not an Afterthought
One striking biological reality is that the clitoris has one primary job: sensation. Unlike
the penis, which must serve multiple functions, urination, ejaculation, penetration, and
sensation, the clitoris is devoted entirely to pleasure. The penis, biologically, must
extend outward because it has a specific reproductive task: to penetrate and deliver
DNA from one body into another. The clitoris does not have that responsibility. It is not
smaller because it is less important, hidden, or secondary; it is structured differently
because its function is different. Rather than extending outward, the clitoris is largely
internal and far more expansive than most people realize. The visible glans is only the
tip of the organ. Internally, the clitoris extends deep into the body through its paired
crura and bulbs, wrapping around and surrounding the vaginal opening. This anatomy
allows the clitoris to be stimulated in multiple ways, including indirectly during vaginal
penetration. Taken together, this design makes one thing clear from a biological
perspective: sexual pleasure in female bodies is not accidental or incidental, it is
intentional, built into human anatomy from the start.
Wet, Hard, Aroused, But Not Always in Sync
Both male and female genitals respond to sexual arousal through the same
fundamental physiological processes, sometimes visibly, and sometimes not at all, even
when a person feels mentally or emotionally aroused. During arousal, erectile tissue fills
with blood, glands release lubricating fluid, and the urethra becomes partially
compressed, which is why urination can feel difficult during or immediately after sexual
activity. At the same time, the nervous system shifts into an arousal-dominant state,
prioritizing sexual response over functions like bladder emptying. Culturally, we tend to
describe this as “penises getting hard” and “vaginas getting wet,” but from a biological
perspective, this framing is incomplete and often misleading. Physical signs of arousal
do not always align with desire, pleasure, or interest, a phenomenon known as arousal
non-concordance, which is normal human physiology. Bodies can respond reflexively
without conscious desire, and people can experience desire without obvious physical
signs. Brains assign meaning to sensation; bodies carry out reflexes. Neither, on its
own, defines readiness, interest, or enjoyment.
The Hymen: A Cultural Story, Not a Biological Marker
The hymen is one of the clearest examples of how anatomy becomes metaphorized.
From a biological standpoint, the hymen does not “break” permanently, it usually does
not bleed, and its appearance does not indicate sexual history in any reliable way.
Hymenal tissue varies widely between individuals and may be minimal or entirely
absent, and it has no known reproductive or protective function. Despite this, culture
transformed the hymen into a symbol of virginity, morality, and worth. That narrative was
never grounded in anatomy or physiology, it was a social construct imposed onto a
neutral piece of tissue, serving not biology, but control. This same kind of
metaphorization shows up elsewhere in how female anatomy has been described and
judged. The vulva was labeled as “tucked away” or hidden, and that physical
arrangement was assigned meaning, suggesting modesty, secrecy, or shame, because
women’s worth was historically tied to virginity and sexual restraint. In reality, female
external genitalia are not positioned the way they are for cultural reasons, symbolism, or
morality; they are arranged that way because of biology, development, and reproductive
function. The idea that anatomy reflects virtue is not anatomical truth, it is a cultural
story layered onto neutral human tissue.
Intersex Bodies Prove the Point
Intersex is loosely defined as naturally occurring variations in sex characteristics, such
as genital anatomy, chromosomes, gonads, or hormone patterns—that fall outside what
are typically labeled as strictly male or female. Intersex traits occur in a small but
meaningful portion of the population, and estimates vary depending on how broadly
those traits are defined. Some academic reviews suggest rates around 1.7 % when a
wide range of biological variations are included, while clinically obvious ambiguous
genitalia occur in roughly 1 in 2,000–4,500 births (1, 2)
These individuals still have the same anatomical parts; those parts are simply organized
differently along a natural spectrum of human development. This is not pathology or
abnormality, it is variation. Just like differences in labial size, penile shape, skin tone, or
any other human body trait, intersex anatomy reflects the wide diversity of healthy
human bodies rather than something that needs to be corrected or explained away.
These variations arise from normal differences in human development and reflect the
biological reality that sex exists along a spectrum rather than as a rigid binary.
Why This Matters in Sexual Health and Rehab
When patients don’t know what normal looks like, they often fill in the gaps with
assumptions: that pain is inevitable, that dysfunction reflects personal failure, that their
body is broken, or that pleasure is something meant for other people. Shame,
comparison, and avoidance then take root, blocking healing long before muscles,
nerves, or tissues ever get a chance to respond to treatment. Before patients can
experience pleasure, or even basic comfort, they must first be able to see their bodies
as normal, functional, and worthy of care.
The First Step Isn’t Performance, It’s Familiarity
One of the most powerful starting points in sexual health is simple body familiarity. Not
arousal, not orgasm, and not goals, just curiosity. This can begin with looking at one’s
own genitals in a calm, observational way. For vulva owners, that may mean gently
separating the folds, lifting the clitoral hood, and noticing what is there without judgment.
For penis owners, it may mean observing the shaft, glans, foreskin if present, scrotum,
and perineum, how the tissue looks at rest, how it changes with touch or temperature,
and what feels neutral, pleasant, or sensitive. This is the same kind of familiarity we
have with our hands, our face, or our elbows: functional, non-performative, and
grounded in awareness. Building comfort with one’s own anatomy creates safety and
self-trust. Comfort comes before confidence, and acceptance comes before pleasure.
The Takeaway
Everyone has the same basic anatomical parts, they are simply arranged in different
ways. Variation is not deviation; it is the rule of human biology. As rehab providers, our
role is not to rank bodies, fix bodies, or attach meaning or morality to bodies, but to
teach anatomy and physiology clearly, confidently, and without judgment. When patients
understand how their bodies are built and why they function the way they do, they can
stop questioning whether they are normal and start trusting themselves. Because they
are normal. All of it is normal. All of it is healthy. All of it is beautiful. That isn’t affirmation
or reassurance, it’s anatomy, and it’s the foundation of empowered sexual health.
References:
1. Sax, L. (2002). How common is intersex? A response to Anne Fausto-Sterling. Journal
of Sex Research, 39(3), 174–178. https://doi.org/10.1080/00224490209552139
2. Abualsaud, D., Hashem, M., AlHashem, A., & Alkuraya, F. S. (2021). Survey of
disorders of sex development in a large cohort of patients with diverse Mendelian
phenotypes. American Journal of Medical Genetics Part A, 185(9),
2789–2800. https://doi.org/10.1002/ajmg.a.61876