The Internal Clitoris: See What is Hidden Inside

Most of the clitoris is hidden from view inside the body. All we can see and touch are the glans, and to a varying degree, the projecting segment of the body, under their concealing layer of soft tissue. The following images and video provide us with a view of what is hidden inside.

The 3D Clitoris: Showing the Glans, Body, Crura, and Bulbs
This is the appearance of the erectile structures of the clitoris, when we view the vulva straight on. These erectile structures surround the urethra and vagina on three sides. In these images, the body and crus are red, the glans pink, and the bulbs purple. The glans is not located internally, nor erectile in nature, it is shown to provide a point of reference.

All the internal clitoral structures, body, crura, and bulbs, are erectile in nature [1][2][4]. The crura extend into and become conjoined within the body, where they remain separated by a layer of fibrous tissue, a septum. Erectile tissue contains hollow spaces that fill with blood during sexual arousal. If erectile tissue is contained within a tissue layer that doesn't stretch, it becomes firm to the touch during sexual arousal. Envision multiple empty balloons inside an otherwise empty cylinder shaped plastic bag. Now envision the balloons filling with water, causing the plastic bag to expand and become rigid.

The Erectile Structures of the Penis and Clitoris
The erectile structures of the clitoris and penis. Source

The body and crura contain erectile tissue that is surrounded by a layer of constrictive tissue that allows them to become firm, 'erect', during sexual arousal [1]. The bulbs contain erectile tissue but a less constrictive outer tissue layer, which means they can become 'engorged', but not erect [1][2][9]. The erectile structures of the penile shaft are contained within two layers of constrictive tissue, which allows it to become truly erect, whereas the clitoris is believed to only become firmer [3][9]. The fully 'erect clitoris' probably is not as firm as a fully 'erect penis'. It is unknown if this is equally true of clitorises that are highly developed***.

The clitoris is prevented from pointing upwards during sexual arousal by its suspensory ligament [1]. Based on some anatomy illustrations, the suspensory ligament and tendons of the bulbospongiosus and ischiocavernosus muscles may limit or prevent access to the clitoral body during sexual stimulation. Those structures are not shown here, to allow clear representation of the internal clitoris. Each woman needs to determine for herself how accessible her clitoris is, and demonstrate this to her sexual partner.

The clitoral glans contains 'minimal spongy tissue' that is not erectile in nature [2], it corresponds to the corpora spongiosum of the penile glans. The amount of spongy tissue is dependent on the level of clitoral development. The glans is rich in blood vessels, but has no cavernous areas. In all clitorises, the erectile structures of the body, the paired corpora, project slightly into the glans [1], and may result in the glans feeling firm to the touch during sexual arousal. The inner labia are made up of the same tissue as the glans, and both fill, become engorged, with blood during sexual arousal.

MRI Images of Clitoris During Sexual Arousal
These MRI scans allow us to see the changes in the internal structures of the clitoris during sexual arousal. The arrows point to the crura. In the center image, the urethra has been highlighted in red, the vagina blue. Source

The 3D illustrations presented here are based on MRI images of a single clitoris. The appearance of the clitoris, and its size and structure, vary greatly between individuals, depending on factors like genetics, age, presence of chronic disease (diabetes and cardiovascular), and hormone levels [2][4][6]. 'The erectile tissue structures [are] more bulky and more easily defined in...younger' women [4]. A woman, or her partner, should not expect her anatomy to be exactly as shown.

The size of the internal clitoral structures vary significantly between women, with the largest being more than twice that of the smallest. The body's width varies from 0.4 to 0.8 inches (1 to 2 cm.) and the length from 0.8 to 1.6 inches (2 to 4 cm.) [4]. The crura are 2.0 to 3.5 inches (5 to 9 cm.) long [4]. The bulbs are 1.2 to 2.8 inches (3 to 7 cm.) in length, and vary in shape from 'crescentic' to 'triangular' [4]. For some women, the bulbs are more closely related to the clitoris and urethra than the vagina [4]. The varying size and shape of these structures is demonstrated in two photographs shown below. Given the amount of anatomical diversity, should we expect all women to have identical sexual responses and experiences?

MRI Image and Illustration Showing the Clitoris
This is one of the MRI images and illustrations used to create the 3D images. Images are of a 'Healthy, Premenopausal' woman. Source

The clitoral glans and hood, and the soft tissue covering the body (highlighted in red in the following photo), are part of the somatic nervous system and sensitive to the full range of stimulation. The projecting portion of the clitoral body has somatic sensory nerve endings located on the surface of the erectile structures that are sensitive to pressure and vibration, and a woman may feel her clitoral body become engorged with blood [2], and perhaps pulse and throb. The nerve endings are located along the top two-thirds of the clitoral body, adjacent to the path of the dorsal nerve and its lateral offshoots [5].

Photo of Vulva with Hood and Clitoris Identified Photo of Vulva with Hood and Clitoris Identified
The hood and soft tissue covering the body of the clitoris are highlighted in the left photograph. The photograph on the right reveals the approximate location of the clitoris. When stimulating the clitoris, causing the hood to move will stimulate the clitoral glans, which is sensitive to the full range of stimulation.

The nerves internal to the erectile structures, body, crura, and bulbs, are part of the autonomic nervous system and described as 'microscopic and difficult to define consistently' [1], and 'few and thin' [10]. These nerves are associated with the smooth muscle fibers and blood vessels responsible for erection [10]. This likely means the erectile structures are, at most, sensitive to pressure and pain. While not shown here, the crura and bulbs are covered by a thin layer of muscle****, and other tissues [4], which prevents them from being directly stimulated. In the photograph shown below on the left, observe how the bulb on the right (under the word "urethra") remains concealed by tissue, as would be the case in a living woman. The internal erectile structures don't have nearly as many nerve fibers as the glans [2]. The bulbs have even fewer nerve ending than the body and crura [1].

"[T]he female CN [cavernous nerve] [to the crura] contains no sensory fibers." [11]

"The sensory function of the clitoris may be exclusively supported by the…somatic nervous system, through PN [pudendal nerve] branches, including the DCN [dorsal clitoris nerve] [to the clitoral glans and body]." [11]

"Increased density of small nerves in the glans suggests this is the location of heightened sensation. Decreasing quantity of nerves in segments closer to the urethra may indicate these zones are less important for sexual sensation."[13]

Front View of Dissected Clitoris Side View of Dissected Clitoris
These photographs of a dissected vulva, of a 57-year-old postmenopausal woman, show the internal clitoral structures. The clitoral body and crura have been highlighted in red, the glans pink, and the bulbs purple. The size of the clitoral structures decrease during menopause, as a result decreasing hormone levels. The blue rectangles represent an area that is half an inch wide and one inch long (1.3 x 2.5 cm). This dissected clitoris may not be an accurate representation of the clitoris of a living woman, especially of a woman of reproductive age. Source

It seems unlikely, from an anatomical perspective, for the internal erectile structures of the clitoris to be major erogenous zones. The clitoris has thousands of nerve endings*, but they are located within the glans, not the internal structures. The somatic nerves of the clitoral body are located along the side opposite the vagina. There is little or no reason to believe stimulation of these internal clitoral structures during vaginal stimulation should result in a "clitoral orgasm." The sensitivity of the front wall of the vagina, the location of the G-Spot, is unrelated to these deeper clitoral structures, as the bulbs are located above the urethra, not within the vaginal wall.

clitoral body with dorsal nerve
This illustration shows the branches of the dorsal nerve, highlighted in blue, as they travel along the body of the clitoris. These nerves are normally large and visible to the naked eye, and are responsible for the sensitivity of the clitoral glans. The cavernous nerves, responsible for controlling blood flow and engorgement, have merged with the dorsal nerves just prior to reaching this area [12]. Image Source
If the internal clitoris was sensitive to stimulation, and accessible to stimulation, it seems likely a significant number of women would indicate the front AND sides of their vagina were equally sensitive to stimulation. Unfortunately, my survey addressing vaginal sensitivity doesn't allow women to indicate if this specific situation is true for them, only allowing them to indicate whether the front OR sides are sensitive. But, I don't recall anyone stating this was true, and generally the media is quick to point out vaginal erogenous zones. Since the majority of women indicate their vagina is less sensitive to stimulation than the external clitoris, this would appear to indicate the internal clitoris isn't a common and/or major erogenous zone. While unlikely, it is still a possibility, as some women indicate their cervix is an erogenous zone, despite being an 'internal' reproductive organ.
The location of the clitoris relative to the penis during intercourse The location of the clitoris relative to the penis during intercourse
MRI of Coitus with Clitoris Identified MRI of Coitus with Clitoris Identified
The images on the right reveal the approximate location and size of the internal clitoris during sexual intercourse, in the missionary position. In the bottom images, the penis is labeled 'P', Bladder 'B', Uterus 'U', and Pubic Bone 'S'. Source of MRI Images

The images shown above provide an indication of why vaginal intercourse often times doesn't result in orgasm for women. Keep in mind, the only portion of the clitoris sensitive to soft touch and frictional stimulation is the relatively tiny glans, which is located up and away from the penis during intercourse, not to mention covered by a protective hood. The penis may apply pressure to the erectile structures of the clitoris, but from an anatomical perspective, there is little to no reason to believe this should result in vaginal orgasm.

The Vulva with the Internal Clitoris Shown in 3D The Vulva with the Internal Clitoris Shown in 3D
The bottom image reveals the approximate location and size of the internal clitoris.

For men, and women with access to a penis, studying the much larger and prominent penis will provide some indication of the sensitivity of the various portions of the clitoris, as '[c]litoral and penile histology [microscopic structure] appears very similar' [2]. An uncircumcised penis more closely resembles a clitoris than a circumcised one. Consideration of how men masturbate, and enjoy having their penis manually and orally stimulated, will provide some indication of how to stimulate the clitoris. In general, men find the glans, and area surrounding its junction with the shaft, the most sensitive, and this appears to be equally true of women.

The major constraints with this advice are, many if not most women do not have an accessible shaft to their clitoris, and their clitoral glans tends to be even more sensitive to stimulate than the penile glans, as a result of the same, if not greater**, number of nerve endings being contained in a much smaller area. In addition, while the penis can be grasped in the hand, the clitoris can only be caressed with the fingers. The best way to learn how a woman likes to stimulate her clitoris is to watch her masturbate to orgasm, and then have her guide your hand with hers, as she teaches you what works best for her. A woman's masturbation technique(s) provide a good indication of which areas of her body are sensitive to sexual stimulation, and as a result are erogenous zones.

Side View of Dissected ClitorisSide View of Dissected Clitoris 2
These photographs allow us to see how much the shape, size, and location of the bulbs vary between women, as well as the body and glans. The clitoral body and crura have been highlighted in red, the glans pink, and the bulbs purple. The image on the right has been scaled to match the other, and rotated so the crura are at the same angle. If the bulbs were sensitive to penile thrusting during intercourse, would we expect both women to experience the same amount of stimulation, and be equally orgasmic? Source
The 3D Clitoris - Back View
The erectile structures of the clitoris, as viewed from behind.
The 3D Clitoris Side View
The erectile structures of the clitoris, as viewed from the side.
Side view of vulva with internal clitoris Side view of vulva with internal clitoris
The image on the right reveals the approximate location and size of the internal clitoris.
Side view of pelvic organs with the internal clitoris
Side view of pelvic organs with the internal clitoris
The bottom image reveals the approximate location and size of the internal clitoris, in relation to the internal pelvic and external genital organs. In the MRI image, the clitoris is shown near the center of the body, as a result the full length of the "Body of clitoris" and "Bulb" aren't indicated. The 3D clitoris represents the entire clitoris and bulb. In the MRI, the darker structure of the urethra can be seen projecting into the wall of the vagina. The three reported erogenous zones of the vagina are indicated in another version of these images. On the overlay, U = Urethra, V = Vagina, C = Cervix, B = Bladder, IL = Inner Labia, OL = Outer Labia, H = Hood, and the * indicates where the urethra projects into the vaginal wall. Larger MRI and Illustration - Source
Vulva shown from front with clitoris Vulva shown from front with clitoris
The image on the right reveals the approximate location of the clitoris.
A 3D View of the Internal Clitoris - 320 x 180 Video - 640 x 480 Video - View with Windows Media Player

Related Articles :

Anatomy of the Vulva

Locating the Clitoris

Anatomy of the Vagina

Locating the Vagina

Female Ejaculation with 3D images of the female prostate, vagina, and uterus.

Notes:

* While popular texts and websites state how many nerve endings are present, I have not found a medical reference that substantiates their statements.

** While popular texts and websites frequently state the clitoris has more nerve endings than the penis, I have not found a medical reference that substantiates their statements. A medical article titled Cutaneous Corpuscular Receptors of the Human Glans Clitoris: Descriptive Characteristics and Comparison with the Glans Penis published online in May 2013 states "Some authors have claimed that the clitoris is the most densely innervated part of the human body, but this claim is difficult to confirm, as there is no universally accepted method of quantifying the density nerve fibers and corpuscles in the human skin."

*** The largest 'clitorises' appear to occur concurrently with Partial Androgen Insensitivity Syndrome (PAIS), meaning the person is intersexed, and they may see themselves as male, female, both, or neither, and having a penis or clitoris.

**** The muscles covering the clitoral bulbs and crura contract automatically as a result of stimulation of the area between the anus and urethral opening [9]. This may apply pressure to these structures, which a woman may or may not be aware of. It seems possible for women to perceive this as pressure or swelling in the area of the vulva.

References:

1 Helen E. O'Connell, Kalavampara V. Sanjeevan, John M. Hutson. Anatomy of the Clitoris, The Journal of Urology, Volume 174, Issue 4, Part 1, Pages 1189-1195, October 2005 .

2 O'Connell, H. E., Anderson, C. R., Plenter, R. J. and Hutson, J. M.: The clitoris: a unified structure. Histology of the clitoral glans, body, crura and bulbs. Urodinamica, 14: 127, 2004

3 Toesca A, Stolfi VM, Cocchia D. Immunohistochemical study of the corpora cavernosa of the human clitoris. J Anat 1996;188:513.

4 O’Connell, H. E., Hutson, J. M., Anderson, C. R. and Plenter, R. J.: Anatomical relationship between urethra and clitoris. J Urol, 159: 1892, 1998

5 Laurence S. Baskin, Selcuk Yucel, Gerald R. Cunha, Stephen E. Glickman and Ned J. Place, A Neuroanatomical Comparison of Humans and Spotted Hyena, a Natural Animal Model for Common Urogenital Sinus: Clinical Reflections on Feminizing Genitoplasty, The Journal of Urology Vol. 175, 276-283, January 2006

6 Salvatore Caruso, Antonio Cianci, Chiara Malandrino, Lidia Cavallari, Orazio Gambadoro, Grazia Arena, Letterio Pispisa, Carmela Agnello, Mattea Romano, Vittorio Cavallari, Ultrastructural and quantitative study of clitoral cavernous tissue from living subjects, J Sex Med. Jun ;8 (6):1675-85, 2011

7 Yang, C.C., Bradley W.E., Neuroanatomy of the penile portion of the human dorsal nerve of the penis, British Journal of Urology 82, 109-113, 1998

8 Van Anh T Ginger, Christopher J Cold, Claire C Yang, Surgical anatomy of the dorsal nerve of the clitoris, Neurourol Urodyn; 30 (3):412-6, March 2011

9 Nieves Martin-Alguacil, Justine M. Schober, Dale R. Sengelaub, Donald W. Pfaff, and Deborah N. Shelley, Clitoral Sexual Arousal: Neuronal Tracing Study From the Clitoris Through the Spinal Tracts, J Urol. October; 180(4): 1241–1248, 2008.

10 Amelia Toesca, Vito M. Stolfil, and Domenico Cocchia, Immunohistochemical Study of the Corpora Cavernosa of the Human Clitoris, J. Anat. 188, pp. 513-520, 1996

11 David Moszkowicz, MD, Bayan Alsaid, MD, Thomas Bessede, MD, Mazen Zaitouna, MD, Christophe Penna, MD, Gérard Benoit, MD, and Frédérique Peschaud, MD, Neural Supply to the Clitoris: Immunohistochemical Study with Three-Dimensional Reconstruction of Cavernous Nerve, Spongious Nerve, and Dorsal Clitoris Nerve in Human Fetus, J Sex Med 8:1112–1122, 2011

12 Milou D. Bekker, MD, PhD, Cornelis R.C. Hogewoning, MSc, Chris Wallner, MD, PhD, Henk W. Elzevier, MD, PhD, and Marco C. DeRuiter, PhD, The Somatic and Autonomic Innervation of the Clitoris; Preliminary Evidence of Sexual Dysfunction after Minimally Invasive Slings, J Sex Med 9:1566–1578 2012

13 Susan H. Oakley MD, George K. Mutema MD, Catrina C. Crisp MD, M. Victoria Estanol MD, Steven D. Kleeman MD, Angela N. Fellner PhD, Rachel N. Pauls MD, Innervation and Histology of the Clitoral–Urethal Complex: A Cross-Sectional Cadaver Study, J Sex Med Volume 10, Issue 9, pages 2211–2218, September 2013