The clitoris is a sexual organ located at the front of the vulva, and most of it is hidden inside the body. What’s visible from the outside, a small nub of tissue at the top of the vulva, is only one part of a much larger structure that extends several inches internally, wrapping around the vaginal canal. Its primary function is sexual pleasure, and it contains roughly 10,280 nerve fibers, making it one of the most sensitive structures in the human body.
External and Internal Anatomy
The part you can see, called the glans, sits at the top of the vulva just below the pubic bone. It’s small, with an average width of about 3.4 millimeters and a length of about 5.1 millimeters, though size varies from person to person. The glans is covered by a fold of skin called the clitoral hood, similar to the foreskin of a penis. Despite being the only visible portion, the glans is densely packed with nerve endings and is the most sensitive part of the entire structure.
Behind the glans, the body of the clitoris extends inward and then splits into two legs called crura. Think of the shape as a wishbone: the body is the top, and the two crura form a V that stretches downward along either side of the vaginal canal and urethra. The crura are the longest parts of the clitoris. Nestled between the crura and the vaginal wall are two additional structures called vestibular bulbs, which are made of erectile tissue that swells during arousal. At the point where the crura meet, a cluster of nerves converges at what’s known as the root.
This internal architecture wasn’t well understood until relatively recently. In 2005, Australian urologist Helen O’Connell used MRI imaging and dissection to map the clitoris in three dimensions, concluding that typical textbook descriptions lacked detail and were often inaccurate. Her work showed that the clitoris has a broad attachment to the pubic arch and is centrally connected to both the urethra and vagina, making it far more anatomically significant than a simple “button” at the surface.
How It Develops Before Birth
Early in embryonic development, a structure called the genital tubercle forms in every fetus regardless of sex. This tissue is bipotential, meaning it can become either a clitoris or a penis depending on hormonal signals. If androgens (hormones like testosterone) are present, the tubercle develops into a penis. Without that hormonal influence, it develops into a clitoris. This shared origin is why the two organs have parallel structures: the clitoral crura correspond to the penile shaft tissue, and the vestibular bulbs correspond to the spongy tissue surrounding the male urethra.
Nerve Supply and Sensitivity
A 2023 study that directly counted nerve fibers in clitoral tissue found approximately 10,280 myelinated nerve fibers innervating the glans clitoris. That number only accounts for one type of nerve fiber. When unmyelinated fibers and additional nerve contributions from deeper tissue are included, the total count is significantly higher. For decades, the commonly cited figure was 8,000 nerve endings, but this newer histological work confirmed the true number exceeds that estimate.
These nerve signals travel through the dorsal nerve of the clitoris, a branch of the pudendal nerve. The pudendal nerve originates from the lowest part of the spinal cord, connecting to sacral nerve roots in the lower back. This nerve pathway carries sensory information (touch, pressure, pleasure, pain) from the clitoral tissue to the brain. The same nerve also branches to other parts of the pelvic floor, which is why sensations during arousal often feel more diffuse than a single point of contact would suggest.
What Happens During Arousal
In its resting state, the smooth muscle tissue throughout the clitoris stays contracted, limiting blood flow. When sexual stimulation occurs, nerve endings and blood vessel walls release a signaling molecule that relaxes the smooth muscle inside the clitoral arteries. This relaxation allows blood to rush into the erectile tissue of the crura and vestibular bulbs, causing them to swell. The glans becomes engorged and slightly protrudes, increasing its sensitivity to touch.
This process closely mirrors what happens in penile erection, which makes sense given their shared embryonic origin. The vestibular bulbs also fill with blood, adding pressure around the vaginal opening. The entire response is coordinated through spinal reflexes that simultaneously affect the clitoris, labia, and vaginal walls.
Changes With Age and Menopause
The clitoris is a hormone-sensitive organ, and its tissue composition shifts over a lifetime. A study comparing clitoral tissue in younger adults (ages 20 to 40) with tissue from women over 60 found notable structural differences. Collagen, the stiff connective tissue that provides structure, nearly doubled in density, rising from about 24% to 46% of the tissue volume. Meanwhile, smooth muscle and elastic fibers both decreased. Less smooth muscle means the erectile tissue has a reduced capacity to relax and engorge, and less elasticity means the tissue is stiffer overall.
These changes are driven largely by declining estrogen levels during and after menopause. Research has shown that hormone replacement therapy can increase blood flow through the deep clitoral artery, which may partially counteract these tissue changes. Reduced blood flow and tissue stiffness can both contribute to decreased sensitivity, though the degree varies widely between individuals. Women with diabetes tend to experience more pronounced thinning of clitoral smooth muscle, even before menopause.
Why It Was Historically Overlooked
O’Connell’s 2005 research noted that one of the most comprehensive and accurate descriptions of clitoral anatomy had actually been published by Georg Ludwig Kobelt in the mid-1800s. Yet for over a century afterward, medical textbooks either reduced the clitoris to a simple dot on a diagram or omitted internal structures entirely. O’Connell found it was impossible to accurately represent clitoral anatomy in a single flat diagram, the standard format used in most textbooks, because the organ is a complex three-dimensional structure with attachments in multiple planes.
This long gap in anatomical knowledge had real consequences. Without understanding the full size and position of the clitoris, surgeons performing pelvic procedures had limited guidance for avoiding nerve damage. And patient education around sexual health routinely left out the internal structures that account for most of the organ’s tissue. The use of MRI to image the clitoris in living patients has since made it possible to study the organ without relying solely on cadaver dissection, improving both surgical planning and general understanding of pelvic anatomy.