Clitoris

Location and definition

The clitoris is an erectile structure, homologous to the male penis. It is located inferior to the mons pubis at the anterior end of the vulva where the two labia minora meet. Similar to the penis, it is composed of paired crura, a body and a glans.

Unlike its male counterpart however, the clitoris is not circumscribed by a foreskin nor is it perforated by the urethra (and, therefore, has no urinary role). Instead, urethra opens separately, just posteriorly to the clitoris. In addition, most (i.e. four-fifths) of the clitoris is internal; only its glans (measuring an average length of 5 to 8 mm) is externally positioned. This is why the clitoris is informally described as having two parts: the internal and external.

Test yourself on the location and surrounding structures of the clitoris with this quiz.

Internal clitoris

The clitoris arises as a pair of crura, two erectile structures which attach to the ischiopubic rami. Anteriorly, each crus converges to form the paired corpora cavernosa of the clitoris, which are collectively known as its body and are enclosed in a layer of dense fibrous connective tissue (known as the tunica albuginea). In females, the corpus spongiosum is represented as two bodies of erectile tissue in each of the labia minora, referred to as the bulbs of the vestibule or clitoral bulbs.

The clitoris is supported by the suspensory ligament of the clitoris, a fibrous band that connects the clitoris to the pubic symphysis.

External clitoris

At its distal extremity, the body, which is formed by the junction of both corpora cavernosa, is surmounted by the glans (head) of the clitoris, which is a small tubercle of erectile tissue that arises from the junction of the vestibular bulbs (mentioned below).

Externally, the glans is enclosed between the prepuce of the clitoris anteriorly and frenulum of the clitoris posteriorly, which are folds formed by the division of the anterior extremities of the labia minora.

Blood supply and innervation

The neurovascular bundle of the clitoris is located posterior to the corpora cavernosa, between the tunica albuginea and the clitoral fascia. Two dorsal arteries (branch of the internal pudendal artery) supply blood to the fascia and skin over the clitoris. They each give off a branch known as the deep artery of clitoris, which supplies blood to the ipsilateral corpus cavernosum, engorging it during sexual arousal.

Paired dorsal veins of the clitoris are located centrally, medial to their arterial counterpart, and deep to an unpaired superficial vein of the clitoris. Finally, the most lateral structures of the neurovascular bundle are the dorsal nerves of the clitoris.

The dorsal nerve of clitoris is a terminal branch of the pudendal nerve, which travels along the dorsal surface of the clitoral body to the glans. Here, it terminates as a network of highly sensitive free nerve endings and other mechanoreceptors making it one of the densely innervated regions of the body. Like the arteries and the veins, it lies superficially located between the tunica albuginea and the clitoral fascia, and therefore some procedures (e.g. vulvoplasty) may risk injury to this nerve and affect clitoral sensation and sexual function.

Function

During sexual arousal, the clitoris, along with the entire female genitalia, fills with blood. This is due to the ischiocavernosus and bulbocavernosus muscles contracting and compressing the clitoral veins while the arterial blood flow remains; this increased blood then fills the venous spaces in the corpora cavernosa of the clitoris, leading to its ingurgitation. As the clitoris is richly innervated by sensory fibers, stimulation of the clitoris (either direct physical stimulation or mental simulation) may lead to female orgasm.