The clitoris is a mostly internal organ built from erectile tissue, nerve fibers, and blood vessels that work together to produce sexual sensation and orgasm. What’s visible on the outside, the small rounded tip called the glans, is only a fraction of the full structure. The rest extends several centimeters inside the body, wrapping around the vaginal canal and urethra in a wishbone-like shape.
The Full Structure Beyond the Surface
Most anatomy diagrams only show the glans, which sits beneath the clitoral hood at the front of the vulva. But the clitoris is a multiplanar structure with a broad attachment to the pubic bone and deep connections to the surrounding tissue. MRI imaging has mapped its full extent: from the glans, the organ narrows into a shaft (the body), which then splits into two legs called crura that extend backward along the pubic arch. Flanking the vaginal walls on either side are two bulbs of erectile tissue that are also part of the clitoral complex.
This internal network of erectile tissue surrounds the vaginal canal and urethra from the front and sides. The bulbs, the crura, and the body are all continuous with one another and share the same type of spongy, blood-filling tissue. Australian urologist Helen O’Connell’s landmark MRI research in the early 2000s was instrumental in redefining the clitoris as this larger organ rather than just the external nub. Her imaging confirmed that the bulbs should be considered part of the clitoris itself, not separate structures.
How Arousal Works Physically
The clitoris becomes aroused through the same basic mechanism as a penis: blood flows in, fills the spongy erectile tissue, and the tissue swells. During sexual stimulation, the parasympathetic nervous system triggers the release of signaling molecules that relax the smooth muscle in the clitoral arteries, allowing them to widen. Blood rushes into the erectile bodies while the veins that normally drain blood away partially constrict, trapping blood inside. This is called vasocongestion.
As blood fills the tissue, pressure builds inside the erectile chambers. The glans pushes outward slightly, becoming more prominent and more sensitive to touch. The internal bulbs and crura also engorge, which increases pressure around the vaginal walls and urethra. This whole-organ response is why sexual sensation during arousal isn’t limited to the external tip. The internal swelling creates sensitivity across a broader area than most people realize.
The blood supply comes from a branch of the internal pudendal artery. The engorgement process also triggers increased lubrication and heightened sensitivity across the surrounding vulvar tissue, not just the clitoris itself.
An Extraordinary Concentration of Nerves
The clitoris is the most nerve-dense structure in the human body relative to its size. The popular claim that it contains 8,000 nerve endings has circulated for decades, but a 2023 study in the Journal of Sexual Medicine actually counted the nerve fibers for the first time. Researchers found a mean of over 10,000 myelinated nerve fibers in the dorsal nerve of the clitoris alone. When unmyelinated fibers and contributions from deeper nerve branches are factored in, the true count is substantially higher than the 8,000 figure.
These nerve fibers carry touch, pressure, and vibration signals from the glans (which is packed with sensory receptors) through the dorsal nerve, which runs along the body of the clitoris and follows the shape of the erectile tissue from the crura up through the shaft. The signals travel via the pudendal nerve to the spinal cord and then to the brain. This dense sensory wiring is why the glans is so responsive to stimulation and why even light touch registers intensely.
The Role of Hormones
Both estrogen and testosterone are essential for normal clitoral function, and they handle different jobs. Testosterone supports the relaxation of smooth muscle in the clitoral blood vessels, which is the mechanism that allows blood to flow in during arousal. Estrogen maintains the contractile machinery, the ability of those same blood vessels to return to their resting state. Together, these hormones keep the clitoris capable of its full engorgement and recovery cycle.
Women produce testosterone throughout their lives, though levels decline steadily with age. Estrogen drops more sharply at menopause. This hormonal shift can reduce pelvic blood flow, which may decrease the strength of the arousal response and lower genital sensitivity over time. Research in animal models has shown that when both hormones are depleted, clitoral tissue loses function in both directions: it can’t relax fully to engorge, and it can’t contract normally to recover. Restoring one hormone without the other only partially fixes the problem.
How Orgasm Happens
Orgasm involves sensory signals from multiple trigger points, including the clitoris, labia, vagina, and the tissue surrounding the urethra. These signals travel through the spinal cord to higher brain structures. The clitoris is the primary driver for most women, but the internal portions of the organ help explain why vaginal penetration can also contribute to orgasm. The engorgement of the bulbs and crura during arousal puts erectile tissue in direct contact with the vaginal walls, meaning stimulation inside the vagina can indirectly stimulate the internal clitoris.
This is why the old distinction between “clitoral” and “vaginal” orgasms is largely a false divide. The clitoral complex is involved in both. The glans provides direct, concentrated sensation. The internal structures provide broader, pressure-based sensation during penetration. Most orgasms involve some combination of these inputs, with the brain integrating all of them into a single response.
Shared Origins With the Penis
The clitoris and the penis develop from the same embryonic structure, called the genital tubercle. In the first weeks of development, this tissue is identical regardless of chromosomal sex. It has the potential to become either organ. In the presence of androgens (primarily testosterone), the tubercle develops into a penis with a fused tubular urethra. Without androgen signaling, the same tissue develops into a clitoris, with the vestibular folds remaining open to form the labia minora.
This shared origin explains the structural parallels between the two organs. Both contain paired erectile bodies made of the same type of spongy tissue. Both engorge through the same vasocongestion mechanism. Both are innervated by the dorsal nerve running along their length. The key difference is scale and configuration: the clitoral erectile tissue splits into internal branches rather than forming a single external shaft, and the clitoris has no urinary function.
Wide Variation in Size and Shape
There is no standard clitoral size. Clinical studies consistently find far more diversity in clitoral dimensions than textbooks suggest, and the full range of normal is broad. The glans alone varies considerably in width and prominence from person to person. The internal structures also vary in length and volume, which may partly explain why different women respond to different types of stimulation.
Researchers have noted that even basic measurements like average glans diameter in adult women are not well documented, in part because the clitoris has historically received far less anatomical study than the penis. A 2005 study of 50 women found significant diversity in clitoral size, color, and tissue texture, reinforcing that there is no single “normal” appearance.