Clitoral erection (also known as clitoral tumescence or female erection) is a physiological phenomenon where the

clitoris In amniotes, the clitoris ( or ; : clitorises or clitorides) is a female sex organ. In humans, it is the vulva's most erogenous zone, erogenous area and generally the primary anatomical source of female Human sexuality, sexual pleasure. Th ...

becomes enlarged and firm. Clitoral erection is the result of a complex interaction of psychological, neural, vascular, and endocrine factors, and is usually, though not exclusively, associated with

sexual arousal Sexual arousal (also known as sexual excitement) describes the Physiology, physiological and psychological responses in preparation for sexual intercourse or when exposed to Sexual stimulation, sexual stimuli. A number of physiological response ...

. Erections should eventually subside, and the prolonged state of clitoral erection even while not aroused is a condition that could become painful. This swelling and shrinking to a relaxed state seems linked to

nitric oxide Nitric oxide (nitrogen oxide, nitrogen monooxide, or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes den ...

's effects on tissues in the clitoris, similar to its role in penile erection.

Physiology

The clitoris is the homolog to the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

in the male. Similarly, the clitoris and its erection can subtly differ in size. The visible part of the clitoris, the glans clitoridis, varies in size from a few millimeters to one centimeter and is located at the front junction of the

labia minora The labia minora (Latin for 'smaller lips', : labium minus), also known as the inner labia, inner lips, or nymphae, are two flaps of skin that are part of the primate vulva, extending outwards from the inner Vagina#Vaginal opening and hymen, vagi ...

(inner lips), above the opening of the

urethra The urethra (: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, through which Placentalia, placental mammals Urination, urinate and Ejaculation, ejaculate. The external urethral sphincter is a striated ...

. It is covered by the clitoral hood. Any type of motion can increase

blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory system is controlled by homeostasis, homeostatic mechanisms of autoregulation, just as hydrau ...

to this organ and this results in increased secretions which lubricate the

vagina In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vag ...

. There are many ways to stimulate the clitoris. Clitoral erection occurs when the corpora cavernosa, two expandable erectile structures, become engorged with blood. This may result from any of various

physiological Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

stimuli, including

. During sexual arousal, arterial blood flow to the clitoris is increased, and trabecular

smooth muscle Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called bec ...

within the clitoris relaxes allowing blood to engorge the erectile tissues. The

ischiocavernosus The ischiocavernosus muscle (erectores penis ''or'' erector clitoridis in older texts) is a muscle just below the surface of the perineum, present in both men and women. Structure It arises by tendinous and fleshy fibers from the inner surface of ...

and

bulbospongiosus muscle The bulbospongiosus muscles (in older texts bulbocavernosus and, for female muscle, constrictor cunni) are a subgroup of the superficial muscles of the perineum. They have a slightly different origin, insertion and function in males and females. ...

s contract to compress the dorsal vein of the clitoris to stop drainage of the clitoris, trapping the blood. The erectile tissues are composed of endothelium-lined vascular spaces in a trabecular matrix, with the

endothelium The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the r ...

-lined vascular spaces surrounded by smooth muscle capable of contraction and relaxation. During sexual arousal, arterial blood flow to the clitoris is increased, and within the clitoris, the arteries further branch to supply the erectile tissues. The trabecular smooth muscles of the erectile tissue relax increasing blood flow to fill the vascular spaces, and expanding the erectile tissues until they are fully engorged with blood. The ischiocavernosus and bulbocavernosus muscles contract, compressing the dorsal vein of the clitoris. This compression of the vein restricts drainage of the erectile structures, trapping the blood. This process stretches the tunica albuginea. As a result, the clitoris becomes tumescent to accommodate the increased intracavernosous pressure. The tunica albuginea of the clitoris is made up of one layer making it more elastic than the tunica albuginea of the penis, which is composed of two layers. Erick Janssen (2007) elaborates on this reporting that "the corpora cavernosa of the clitoris are essentially similar to that of the penis except that there is no subalbugineal layer interposed between the tunica albuginea and the erectile tissue. In the penis, this tissue engorges with blood during sexual arousal and becomes compressed against the unyielding tunica, creating penile rigiditya true erection. The lack of this plexus in the clitoris indicates that while the organ can become tumescent or engorged, it cannot, like the penis, become stiffly erect. The clitoris thus does not become erect with sexual excitement, but engorged." In addition, the tunica albuginea around the glans is thinner than around the shaft in both the clitoris and penis. This gives the glans less firmness relative to the shaft. The extrusion of the glans clitoridis and thinning of the skin enhances sensitivity to physical contact. After a female has

orgasm Orgasm (from Greek , ; "excitement, swelling"), sexual climax, or simply climax, is the sudden release of accumulated sexual excitement during the sexual response cycle, characterized by intense sexual pleasure resulting in rhythmic, involu ...

ed, the erection usually ends, but this may take time.

Medical conditions

Clitoral priapism

Priapism, while more common in males, is a condition that can also affect the clitoris. Symptoms include painful engorgement, swelling, and pain in the area around the clitoris.

Other animals

Among

capuchin monkey The capuchin monkeys () are New World monkeys of the subfamily Cebinae. They are readily identified as the "Street organ, organ grinder" monkey, and have been used in many movies and television shows. The range of capuchin monkeys includes some t ...

s, clitoral erection is possible and makes the clitoris more visible than in its relaxed state where it is hidden by a preputial fold.Carosi, M, Spani, F, Ulland, AE, Scalici, M, Suomi, SJ. Clitoral length in immature and mature captive tufted capuchin (''Sapajus'' spp.) females: A cross-sectional study. ''Am J Primatol''. 2020; 82:e23135. https://doi.org/10.1002/ajp.23135

Notes

References