There are three distinct openings in the area between a woman’s legs: the urethral opening (where urine comes out), the vaginal opening, and the anus. All three sit within a surprisingly compact stretch of tissue, and surveys suggest that fewer than half of people can correctly count them. In one study, only 46% of participants knew there were three openings, and the urethra was the one most people missed entirely.
Where Each Opening Is and What It Does
The three openings are arranged in a front-to-back line. Starting at the front and moving toward the back, you encounter the urethral opening first, then the vaginal opening, and then the anus. Each connects to a completely separate internal system.
The urethral opening is tiny and easy to overlook. It sits just below the clitoris and above the vaginal opening, and its sole job is to let urine pass from the bladder out of the body. In women, the urethra is short, only about 3 to 4 centimeters long, which is one reason urinary tract infections are more common in women than in men. How close the urethral opening sits to the vaginal opening varies from person to person. Research on women with recurrent urinary tract infections found that the distance between the two openings was shorter in women who got frequent infections compared to those who did not, with a median distance of about 16 millimeters versus 21 millimeters in unaffected women.1PubMed. Clinical implications of the anatomical position of the urethra meatus in women with recurrent post-coital cystitis: a case-control study That difference sounds small, but it matters clinically.
The vaginal opening is larger and sits in the middle of the vestibule, the smooth area between the inner lips (labia minora). It leads to the vaginal canal, which connects to the cervix and uterus. The vaginal opening is partially covered by the hymen, a thin membrane that naturally has one or more openings in it to allow menstrual blood to pass through. The anus, the third opening, is the most posterior of the three and is separated from the vaginal opening by a bridge of tissue called the perineum.
The perineum is worth knowing about because it plays a structural role in supporting all three openings. Anatomical studies describe it as having an inverse trapezoid shape, and it contains connective tissue layers that help anchor the vagina and the surrounding muscles.2PubMed Central. Surgical anatomy of the vaginal introitus During childbirth, this tissue can stretch or tear, and understanding its anatomy is relevant to a number of medical situations.
Why People Get the Count Wrong
The confusion almost always comes down to the urethra. In a questionnaire-based study, participants were asked how many openings a woman has in her external genitalia. Only 46% answered three. Among those who did attempt to label a diagram, 71% could identify the vagina and 67% could identify the anus, but only 35% correctly identified the urethra.3PubMed Central. Public understanding of female genital anatomy and pelvic organ prolapse (POP); a questionnaire-based pilot study The perineum was the least recognized structure overall, identified by just 18% of respondents.
There are a few reasons for this gap. The urethral opening is genuinely hard to see. It is small, it sits in a recessed area, and most people never need to locate it manually unless they are inserting a catheter. Sex education programs often teach that there are “two holes,” meaning the vagina and the anus, without drawing attention to the urethra as a separate opening. And since urination feels like it comes from “the same general area” as the vagina, many people assume one opening handles both functions. It does not. Urine and menstrual blood exit through entirely different passages.
The Smaller Openings Most People Never Notice
Beyond the three main openings, there are several tiny glandular duct openings in the vestibule that most people never see or feel. These are not usually counted when someone asks “how many holes,” but they are real anatomical structures with clinical significance.
The Bartholin’s glands are a pair of pea-sized glands located symmetrically at the back edges of the vaginal opening. They secrete mucus that contributes to vaginal lubrication.4PubMed Central. Clinical Pathology of Bartholin’s Glands: A Review of the Literature Each gland has a small duct that opens into the vestibule, so that is two additional pinpoint openings at roughly the four o’clock and eight o’clock positions around the vaginal entrance. You would not notice them under normal circumstances, but they can become relevant if a duct gets blocked, forming a Bartholin’s cyst, which is one of the more common reasons women visit a gynecologist for vulvar swelling.
The Skene’s glands (sometimes called the paraurethral glands) are located on either side of the urethral opening. Their ducts drain just lateral to the urethra, in the posterolateral position.5PubMed Central. Skene’s glands abscess an overlooked diagnosis in acute lower urinary symptoms Like the Bartholin’s glands, these are functionally invisible to most people but can become the site of cysts or abscesses.
In addition to these named glands, the vestibule contains scattered minor vestibular glands. Histological studies have found anywhere from one to hundreds of tiny mucinous glands in the tissue lining the vestibule.6Sexual Medicine Reviews. Review of the vestibular glands: functional anatomy, clinical significance, and role in sexual function Most of these are microscopic. Taken together, the vestibular region is dotted with many more openings than the three you can see with the naked eye, but from a practical standpoint, the answer to “how many holes” is still three.
The Hymen and How It Changes Things
The hymen is a membrane that partially covers the vaginal opening, and its shape varies widely from person to person. A large review of girls examined for non-abuse purposes found that about 53% had an annular hymen (a ring-shaped opening), 29% had a crescentic shape (open toward the front), and about 15% had a redundant or fimbriated form with extra folds of tissue.7Journal of Pediatric and Adolescent Gynecology. Appearance of the Genitalia in Girls Selected for Nonabuse: Review of Hymenal Morphology and Nonspecific Findings A small percentage had a septate hymen (about 2%), where a band of tissue divides the opening into two.
A septate hymen can create the appearance of two vaginal openings instead of one, which can understandably confuse the count. One case report described a teenage girl who presented to an emergency department with a tampon stuck behind a septate hymen. Examination revealed the band of tissue bisecting the vaginal opening, and a minor surgical procedure (hymenectomy) corrected the anatomy.8PubMed Central. Concomitant Septate Hymen and Bicornuate Uterus: Emphasizing the Need for Thorough Internal Genital Tract Evaluation
On the other end of the spectrum, an imperforate hymen completely blocks the vaginal opening. This is a rare congenital condition that can go unnoticed until puberty, when menstrual blood has no way to exit the body. Symptoms typically include cyclic abdominal pain and the absence of menstrual periods.9PubMed Central. Early Diagnosis of Imperforate Hymen in a Pediatric Patient: A Case Report A systematic review of postnatal cases found that the most common symptoms were abdominal pain (about 54%) and urinary retention (about 20%), and the majority of patients were treated with a straightforward surgical opening of the hymen.10PubMed Central. Imperforate Hymen: A Comprehensive Systematic Review In this condition, a girl effectively has one fewer functional opening until the issue is corrected.
Congenital Variations That Alter the Standard Anatomy
The three-opening layout depends on normal embryonic development. During early pregnancy, around weeks four through seven, a structure called the cloaca divides into separate compartments that will become the urinary tract, the reproductive tract, and the rectum.11PubMed Central. The embryology of persistent cloaca and urogenital sinus malformations When this division does not happen properly, a baby can be born with a persistent cloaca, a condition where all three systems share a single opening. This is rare and requires surgical correction, but it illustrates that the three-opening anatomy we take for granted is the product of a specific developmental process.12PubMed Central. The development of the cloaca in the human embryo
Vaginal septa are another congenital variation. A longitudinal vaginal septum is a wall of tissue running vertically inside the vaginal canal, effectively creating two parallel channels. These are often associated with duplication of the uterus and result from incomplete fusion of the embryonic structures (Müllerian ducts) that form the uterus and upper vagina.13Journal of Pediatric and Adolescent Gynecology. Management of Longitudinal Vaginal Septum with GIA and EndoGIA Stapler Device: A Case Report Transverse vaginal septa run horizontally and can partially or fully block the canal. Both types are rare and often go undiagnosed until they cause problems with tampon use, intercourse, or menstrual flow.14PubMed Central. Vaginal septum in women: A review of diagnosis, management, and obstetric outcomes
When Injuries or Medical Conditions Create Additional Openings
A fistula is an abnormal tunnel connecting two body cavities that are not supposed to be connected. In the pelvic area, the most clinically significant types are vesicovaginal fistulas (connecting the bladder to the vagina) and rectovaginal fistulas (connecting the rectum to the vagina). A vesicovaginal fistula causes urine to leak continuously through the vagina. A rectovaginal fistula allows stool or gas to pass through the vagina. One case report documented a woman who developed both simultaneously after a neglected pessary (a device used to manage pelvic organ prolapse) caused tissue breakdown.2PubMed Central. Surgical anatomy of the vaginal introitus These conditions effectively create new openings that are not part of normal anatomy.
Childbirth is one of the more common causes of trauma to the area. Perineal tears during vaginal delivery range from minor surface tears to severe injuries that extend through the anal sphincter and into the rectal lining. These fourth-degree tears, affecting roughly one to eight percent of vaginal births overall and up to 28% of forceps-assisted deliveries, temporarily disrupt the boundary between the vagina and the rectum.15Cochrane Database of Systematic Reviews. Antibiotic prophylaxis for third- and fourth-degree perineal tear during vaginal birth While these are repaired surgically, they illustrate that the anatomical boundaries between the three openings are maintained by tissue that can be vulnerable to injury.
How the Area Changes Over a Lifetime
The anatomy of the vulvar and vaginal area is not static. Hormonal changes across a woman’s life reshape the tissue significantly. Before puberty, estrogen levels are low, and the tissue is thin and relatively undeveloped. During the reproductive years, estrogen keeps the vaginal walls thick, elastic, and well-lubricated, with visible folds (called rugae) lining the canal.
After menopause, declining estrogen causes a set of changes collectively known as genitourinary syndrome of menopause. The vaginal tissue thins, becomes paler and drier, and loses its rugae. The tissues lose collagen and elastin, blood vessel density decreases, and elasticity drops.16PubMed Central. Vulvovaginal atrophy The cervix may become flush with the vaginal wall rather than protruding into it. The urethral opening can also be affected, becoming more prominent or irritated, which contributes to urinary symptoms like frequency and urgency.17PubMed Central. Addressing Vulvovaginal Atrophy (VVA)/Genitourinary Syndrome of Menopause (GSM) for Healthy Aging in Women
None of these changes alter the number of openings, but they can change how the openings look and feel, and they affect susceptibility to infections and discomfort. The loss of the tissue’s natural acidity and moisture can make the vaginal opening feel smaller or more sensitive, even though the anatomical layout remains the same.
Surgical Procedures That Modify the Openings
Several medical and cultural practices alter the anatomy of the vulvar openings. Episiotomy, a surgical cut made to widen the vaginal opening during childbirth, is one of the most common. It is performed when the perineum appears likely to tear in an uncontrolled way during delivery.
Female genital cutting, practiced in some regions, can dramatically alter the visible anatomy. The most extensive form, infibulation, involves cutting and stitching together the labia to narrow the vaginal opening, sometimes leaving only a small hole for urine and menstrual blood to pass through.18PubMed. Female genital mutilation and cutting: An anatomical review and alternative rites Defibulation, the surgical reopening of this closure, is later necessary to allow intercourse and childbirth. In countries like Norway, defibulation is available on demand through public health services for women who have undergone infibulation, including beyond the traditional contexts of marriage and childbirth.19PubMed. Undoing female genital cutting: perceptions and experiences of infibulation, defibulation and virginity among Somali and Sudanese migrants in Norway
Reconstructive surgeries, such as perineorrhaphy (repair of the perineum), can also change the dimensions of the area. In one anatomical study, perineorrhaphy specimens averaged about 2.9 cm wide and 1.6 cm deep, and the procedure increased perineal length by roughly 28% while reducing the width of the genital opening by about 31%.2PubMed Central. Surgical anatomy of the vaginal introitus These procedures do not add or remove openings, but they reshape the spatial relationships between them.
How Female Anatomy Compares Across Mammals
One reason people sometimes find the three-opening layout surprising is that it is not universal across mammals. A comparative anatomy review found that variation in the female lower genital tract across mammalian species is actually more extensive than variation in male genitalia. In some species, entire anatomical units are absent altogether. Some mammals in the group Xenarthra (which includes armadillos and anteaters) lack a cervix entirely. Others lack a urogenital sinus, or have the clitoris completely separated from the genital canal.20PubMed Central. Female Genital Variation Far Exceeds That of Male Genitalia: A Review of Comparative Anatomy of Clitoris and the Female Lower Reproductive Tract in Theria
In many non-primate mammals, the urethra and vagina share a common exit channel called the urogenital sinus, meaning those species effectively have two external openings rather than three. Humans, along with other primates, have evolved separate urethral and vaginal openings, which is part of what makes the “three holes” layout specifically a human (and primate) characteristic. The embryonic cloaca-to-three-opening development described earlier is the mechanism by which this separation occurs. When that developmental process goes wrong, as in persistent cloaca, the result is an anatomy that resembles the less-differentiated layout found in other species.