ANATOMY

 

What does the clitoris look like and what is it made of? Where exactly is it located? How is it innervated? What is its embryological origin? What is its relation to the penis, if any? Here are some answers taken from the scientific literature (see the page ABOUT for the list of sources used).

The bulbo-clitoral organ or clitoris

The female erectile system consists of the clitoris and the vestibular bulbs, or "bulbs of the vestibule", or "bulbs of the clitoris". The whole system is sometimes referred to as the bulbo-clitoral organ, the clitoral complex, or simply the clitoris. The latter term is not widely accepted in the biomedical literature, in particular because it is confusing given the more restricted meaning that has long been given to the word clitoris. For the same reason, I do not adopt this usage here either.

The bulboclitoral organ is part of the so-called external genitalia, but it is almost completely hidden. It is first buried under the skin and fat of the pubic mound and under the labia, and then largely hidden under bundles of muscles, and in some places by networks of blood vessels and flaps of connective or spongy tissue. 

Four parts are usually differenciated: the crura, the body, the glans and the bulbs, to which one must add the pars intermedia, made up of Kobelt's venous plexus and the tissues that surround it (click here to virtually manipulate the stylized 3D model).

Clitoris_image 1.png

Crura (legs

The two crura of the clitoris are formed by two cavernous bodies (corpora cavernosa), that are erectile tissue covered with a fibrous envelope called the albuginea. They contain cavities that swell with blood as a result of sexual arousal. The crura run along the inner face of the ischio-pubic branches of the pelvic bones, to which they adhere strongly. They are covered by the ischiocavernous muscles. The contraction of these muscles tends to push the blood from the crura towards the body of the clitoris, thus increasing its erection.

Body

The body of the clitoris is formed by the union of the two corpora cavernosa. They are separated from each other by an incomplete medial septum, and the whole is enveloped in the albuginea. The body is first directed forwards and upwards in the same plane as the crura (proximal part of the body), then bends to form the angle of the clitoris, then moves downwards and backwards (distal part of the body, sometimes called the shaft).  At the knee, a ligament keeps the clitoral body suspended from the pubic symphysis. Experiments with injecting fluid into the erectile system after dissection, as well as the relationship between the clitoris and adjacent structures, suggest that the erection of the clitoris does not result in a widening of its angle: the body of the clitoris, like its crura, increases in volume and tightens, but it does not appear to straighten.

Glans

Oblong or conical in shape, the glans is the most distal part of the clitoris, located after the end of the corpora cavernosa. Although it may be dotted with islands of erectile tissue, it usually contains mostly connective tissue. Di Marino and Lepidi (2014) consider it to consist mainly of "involutive spongy tissue", and O'Connell et al (2005), Shih et al (2013) and Jackson et al (2019) conclude from their examination of the glans that it does not contain erectile tissue. It is adjacent to the albuginea on its inner surface, and it is covered with a dermal mucosa on its outer surface. The glans is the only (partially) visible part of the bulbo-clitoral organ, and it is sometimes completely hidden by the hood, a skin fold that is part of the labia minora and/or labia majora and covers its anterior surface. On its posterior surface, it is attached to the labia minora by another skin fold called frenulum.

Bulbs

Each bulb is made up of a corpus spongiosum, that is an erectile tissue similar to corpora cavernosa, but that is not covered with an albuginea. The bulbs communicate with the body of the clitoris (near its angle) via a network of veins called the Kobelt's plexus. The bulbs join above the urethra, just below the base of the clitoral body, and descend on either side of the urethra and of the vagina. They lie in a plane that does not have the same inclination as that of the crura of the clitoris, and are thus buried less deeply. They are covered by the bulbospongiosus muscles, two bundles of muscle fibres inserted backwards at the level of the transverse muscles of the perineum and joining together forwards at the level of the angle of the clitoris.  The contraction of these muscles increases the erection of the clitoris by expelling blood from the bulbs towards the body of the clitoris, but also by compressing the dorsal vein of the clitoris via a band they form at the back of the angle.

Pars intermedia

The pars intermedia is a roughly pyramidal area between the top of the bulbs and the body of the clitoris. This area is generally absent from anatomical diagrams and dissection photographs, and its contours are poorly defined. It consists of the Kobelt's venous plexus, which connects the bulbs to the body of the clitoris, and the connective tissue surrounding this plexus. Macroscopic examination of the pars intermedia may give the impression that it is a spongy tissue similar to that of the bulbs, which sometimes leads to its being presented as an extension of the bulbs. However, histological examination shows that it is of a distinct nature and cannot be described as erectile tissue (Shih et al. 2013). Di Marino and Lepidi (2014) have proposed to call "infra-corporeal residual spongy part" a band of non-significantly erectile involutive spongy tissue that is adjacent to the distal part of the pars intermedia, establishing a vascular connection not only between the bulbs and the body of the clitoris, but also with the vessels of the vestibule walls, which themselves communicate with those of the labia minora..

  Biomedical imaging (click to display full views)                                                                    

 

Dimensions of the clitoris and bulbs

The average dimensions of the clitoris and bulbs, as well as their normal ranges (in the statistical sense of the term), cannot yet be established from the scientific literature. Scientific articles reporting measurements of the clitoris and bulbs are few in number, have been based on small and unrepresentative samples of the general population, and are frequently incomplete. For example, the width of the individual elements (except for the glans) is less often reported than their length, the lengths of the glans and the shaft are better documented than other lengths, and measurements of the angle of the body as well as the angle formed by the two crura are almost non-existent.

Moreover, the dimensions that are reported in the available scientific studies vary widely. In addition to the significant inter-individual variability found in all studies, the demographic characteristics of the samples studied and the methods used in each study also constitute a source of variability. Thus, for example, measurements made on the basis of conventional (2D) MRI can be distorted by the axis of the shot, especially since the different parts of the bulbo-clitoral complex lie in distinct planes. 

In addition, Moreover, the terminology is not uniform: the glans does not always designate the same thing depending on the authors and depending on whether it is a gynaecological visual examination, a histological examination or an examination by MRI; the length of the body sometimes includes that of the glans, or the shaft of the clitoris is unduly called "body", or even "clitoris". Finally, the precise modalities of measurement are rarely described, which creates uncertainty as to the exact positioning of the boundary between crura and body, between proximal and distal parts of the body and between glans and body.

However, it is possible to get an idea of the usual dimensions of the clitoris and bulbs through the following elements.

Reviews of the literature

According to Ginger and Yang (2011), the clitoris can be 10 cm or more in length, of which 5 to 7 cm are for the body (including the glans). According to Pauls (2015), the entire clitoris is 9 to 11 cm long (for measurements of each part, the article uses data from O'Connell et al. 1998). Mazloomdoost and Pauls (2015) give the same measurements except for body length, which was reduced to "0.5 to 3.5 cm" in length probably by mistake due to a too rapid reading of Lloyd et al. (2005) - see below.

As for bulbs, according to Ginger and Yang (2011) their size varies from person to person and could depend on age and estrogenation. According to Mazloomdoost and Pauls (2015), bulbs are 3 to 4 cm long in the flaccid state and up to 7 cm in erection.

Focus on eight studies

[1] Verkauf et al. (1992) - Sample of 200 women aged 14 to 56 years (mean age = 28, median = 35), in vivo study by gynaecological examination

- Glans: mean length = 5.1 mm (standard deviation 1.4 mm), mean width = 3.4 mm (3 to 5 mm in 90% of women, standard deviation 1.0 mm).

- Estimated length of the shaft including glans (wrongly called "total length" of the clitoris): mean = 1.6 cm (1.0 to 2.3 cm in 90% of women, standard deviation 4.3 mm).
- Dimensions on average slightly larger in women who have given birth compared to nulliparous women: glans width 3.6 mm vs 3.2, glans length 5.3 mm vs 4.8, shaft length 16.3 mm vs 15.4. In contrast, there was no statistically significant difference between women depending on their hormonal contraception status, nor was there a statistically significant relationship with age, stature, weight or BMI.
Rem: given the methodology if this study, it may underestimate the total length of the glans + distal part if the body.

[2] O'Connell et al. (1998) - Sample of 10 women aged between 22 and 88 years at death, postmortem dissection study

- Body = "2 to 4 cm" long and "1 to 2 cm" wide.

- Crura = "5 to 9 cm" long and "slightly narrower" than the body.

=> Therefore, the total length, not indicated, was always > 7 cm and < 13 cm in this sample (+ about 5 mm for the glans).

- Bulbs = "3 to 7 cm" long.

Rem: the method for measruring the crura is not specified, they are surprisingly long, and on the contrary the body appears short. It seems therefore possible that the body here actually corresponds only to its distal part, its proximal part being included in the measurement of the crura.

[3] Aubin (2002) - Sample of 5 women of unspecified ages, study by postmortem dissection

- Width of the glans = about 5 mm, body width gradually increasing from 5 to 9 mm away from the glans.
- Length of the glans = 4 to 6 mm.
- Length of the body = "about 2.5 cm" for its distal part, 6 to 8 mm for its proximal part.
- Length of the crura = 4 cm.
=> The total length, not indicated, would therefore be slightly less than 8 cm in this sample.

- Bulbs = 3 to 5 cm long and 15 to 18 mm wide at their largest diameter.

[4] Lloyd et al. (2005) - Sample of 50 non-menopausal women without genital mutilation, in vivo study by gynaecological examination

- Width of the glans: mean = 5.5 mm (min = 3, max = 10, standard deviation = 1.7).
- Estimated length of the shaft (wrongly called "clitoris"): mean = 1.9 cm (min = 5 mm, max = 3.5 cm, standard deviation = 8.7 mm).
Rem: given the methodology of this study, like Verkauf et al. (1992), it is at risk of underestimating the length of the glans + distal part of the body.

[5] Di Marino and Lepidi (2014) - Undescribed sample, postmortem dissection study

- Length of the glans: average = about 5 mm.
- Length of the distal part of the body: average = 32.4 mm.
- Length of the proximal part of the body: average = 12.8 mm (max = 2 cm).
- Length of the crura: average = 37 mm.
=> The average total length, not mentioned, would therefore be just under 9 cm in this sample.
- Bulbs: average length = 3.15 cm (min = 1.5, max = 4.2), average largest width = 2.2 cm (min = 1.3, max = 3.2).

[6] Vaccaro et al. (2014) - Sample of 20 sexually active women, mean age 41.6 years (standar deviation = 11.6), in vivo MRI study.

- Length of the "glans" (misnamed): avg. = 13 mm (standard deviation = 4), width = 5.4 mm (standard deviation = 1.85).

- Length of the "body" (also misnamed) in axial view: avg. = 39 mm (standard deviation = 11.2 mm), half width = 6.9 mm (standard deviation = 1.7).-

- Length of the crura in axial view: avg. = 64 mm (standard deviation = 9.7 mm) and width = 1.0 cm (standard deviation = 3.2 mm).
=> Average total length = 11.6 cm in this sample (authors' calculation).

Rem : this article contains several inconsistencies and uses an erroneous vocabulary that has obviously created some confusion between what was measured and how it was reported. Among other consequences, the total length of the clitoris is probably overestimated here.

[7] Abdulcadir et al. (2016) - Sample of 15 non-menopausal, sexually active women without genital mutilation, mean age = 32 years (+/- 7.3 years), in vivo MRI study.

- Width of the glans: mean = 4.8 mm (standard deviation = 2.7 mm).
- Length of the shaft = glans + distal part of the body (wrongly named "body of the clitoris"): mean = 25.7 mm (standard deviation = 7 mm).

[8] Jackson et al. (2019) - Sample of 22 women aged 48-89 years (median age = 70 years), postmortem dissection study. 

- Glans: median length = 8 mm (min = 5, max = 12) and median width = 4 mm (min = 3, max = 10).
- Body: median length = 29 mm (min = 13, max = 59) and median width at mid-length = 9 mm (min = 5, max = 14).
- Crura: median length = 50 mm (min = 25, max = 68) and median width at mid-length = 9 mm (min = 2, max = 13).
=> The total median length, not indicated and not deductible from the previous ones, could therefore be around 9 cm in this sample. 

- Bulbs: median length = 5.4 cm (min = 1.3, max = 6.9), median largest width = 1.8 cm (min = 0.9, max = 2.9).
 

Dimensions used for the 3D-printable model created in 2016

After a review of the available scientific data, I developed in early 2016 (with the help of Mélissa Richard, mediator at the FabLab of the Cité des sciences et de l'industrie) a first version of a stylized model of the bulbo-clitoral organ. The development conditions of this first version did not allow the initially planned dimensions to be perfectly respected, but they nevertheless remain plausible: the clitoris is 10.5 cm long, including 6 cm for the crura, the bulbs are 4.5 cm long, the glans is 5 mm wide, the body is 5 mm to 1 cm wide, and the largest width of the bulbs is 1.4 cm. With the help of Philippe Cosentino, 3D design enthusiast and biology teacher motivated by the pedagogical use of this model, I have developed a second version which has the following dimensions: the clitoris is 9.5 cm long of which 5.3 cm are for the crura, the bulbs are 4 cm long, the glans is 4.5 mm wide, the body is 5 mm to 2 cm wide, and the largest width of the bulbs is 1.6 cm.

​NB : To ensure the robustness of the model and facilitate handling, the bulbs are fixed at the base of the clitoral body and the Kobelt plexus is not modeled. Printable files are freely available here).

 

Innervation and sexual pleasure

The area has two types of motor and sensory innervation: an autonomic (or vegetative) innervation and a somatic innervation. The autonomic system is in principle the substrate for the automatic control of organic functions. Its efferent nerve fibers control the contraction of smooth muscles, and its afferent nerve fibers provide feedback on the state of the areas they innervate. The somatic system is in principle the substrate for voluntary actions and conscious perceptions. Its efferent fibers control the contraction of skeletal striated muscles, and its afferent fibers ensure the perception of stimuli applied to the areas they innervate.

Autonomic innervation

The autonomous innervation of the genital region depends essentially on the lower hypogastric plexus, the terminal part of which forms the vaginal plexus. The cavernous nerve (which innervates the corpora cavernosa) and the spongy nerve (which innervates the bulbs) originate from this plexus. It is via these nerves that the erection or tumescence related to sexual activity is controlled: under the effect of sexual excitement, their efferent nerve fibers control the relaxation of the smooth muscles surrounding the arteries and cavities of the erectile tissue, which has the effect of causing blood to flow into them. Conversely, detumescence is caused by the contraction of these smooth muscles, which is their usual state.

Somatic innervation

The somatic innervation of the genital area  depends essentially on the pudendal plexus, which is divided into several branches containing both motor and sensory fibers: the nerve of the levator ani muscle, the nerve of the coccygeus muscle, the superior rectal nerve, and in its terminal part the pudendal nerve. The latter has two lateral branches, forming the lower rectal nerve (which innervates the anus and part of the muscles of the posterior pelvic floor) and the perineal nerve (which innervates the bulbs, the labia majora, the labia minora, the vaginal opening, the end of the urethra and the skin of the perineum, and provides motor innervation of the external sphincter of the urethra and most of the pelvic floor muscles), before ending as the dorsal nerve of the clitoris.

The dorsal nerve of the clitoris ensures the innervation of the corpora cavernosa, the glans, the hood and the frenulum. After running along the ischio-pubic bones in the direction of the pubic symphysis, its right and left branches cross the suspensory ligament and then adhere to the albuginea tunic of the clitoral shaft, positioned at 11 am and 1 pm. At this point, they have a diameter of about 2 mm. Branches come out of them to plunge into the body of the clitoris as they run along the shaft, then towards the hood and the frenulum. They plunge to finish in the glans at its junction with the body.

Terminaisons du nerf dorsal du clitoris

Le nerf dorsal du clitoris est essentiellement (voire exclusivement) un nerf sensitif. Les terminaisons de ses fibres nerveuses sont soit libres, soit constituées par un mécanorécepteur. En principe présentes dans le derme, les terminaisons libres sont typiquement à l'origine de la perception de la douleur, et sont aussi impliquées dans celle des démangeaisons et du chatouillement. De telles terminaisons sont présentes dans la peau du gland et les zones cutanées glabres (sans poils) adjacentes. Leur pourcentage par rapport à l’ensemble des terminaisons nerveuses présentes dans cette zone n’est pas documenté, mais elles sont régulièrement décrites comme y étant très nombreuses. Quant aux mécanorécepteurs, on en trouve de plusieurs types. Ont été signalés :

- des disques de Merkel et des corpuscules de Meissner dans le derme du gland et les zones cutanées adjacentes ; ils sont à l’origine de la sensibilité tactile, sensibles à une variation de contact léger avec la peau et pour les seconds également sensibles aux vibrations de fréquences entre 5 et 200 Hz ;

-  des corpuscules de Ruffini dans le capuchon et les autres zones cutanées adjacentes au gland du clitoris ; ils sont en principe sensibles à la chaleur, à la pression et aux étirement cutanés ;

-  des corpuscules de Vater-Pacini dans le tissu conjonctif entourant le nerf dorsal du clitoris, le ligament suspenseur du clitoris, le tissu entourant la tunique albuginée des corps caverneux (y compris dans la partie proximale du corps du clitoris), le tissus adipeux du derme du capuchon, et dans une moindre mesure à la base du gland et à l’intérieur des corps caverneux ; ils sont à l’origine de la sensibilité profonde, sensibles à la pression ainsi qu’aux vibrations de haute fréquence (en principe jusqu’à 1 500 Hz et avec une sensibilité optimale vers 300 Hz) ;

- des corpuscules de Krause dans le gland, et dans une moindre mesure dans le capuchon ; ils sont sensibles aux variations de température et au froid ;

- des corpuscules de Finger ou Krause-Finger dans le gland, en grande quantité ; également appelés "corpuscules de la volupté" eu égard à leur présence documentée uniquement dans le gland du pénis et du clitoris, ils sont semblables aux corpuscules de Krause mais s'en distinguent par leur longueur, l'épaisseur de leur enveloppe et leur aspect mamelonné ; la différenciation entre ces deux types de corpuscules n’est toutefois pas toujours évidente.

Ces corpuscules sont trouvés en quantités très variables selon les spécimens, et il arrive que la présence de l’un ou l’autre de ces types de corpuscules ne soit pas constatée. De plus, le corps du clitoris, et a fortiori les piliers (difficiles à extraire en entier lors des dissections du fait de leur forte adhésion aux os ischio-pubiens) ainsi que les bulbes, ont été encore moins étudiés que le gland du clitoris. Toutefois, plusieurs études indiquent que la densité des terminaisons nerveuses susceptibles d’être à l’origine des sensations érogènes diminue à mesure qu’on s’éloigne du gland, puis de la partie proximale du corps du clitoris et du haut des bulbes. C’est au niveau du gland qu’on observe la plus forte densité de terminaisons nerveuses du clitoris, ce constat étant cohérent avec le diamètre important de la partie terminale de son nerf dorsal, qui contient un grand nombre de fibres nerveuses.

 

Trajet de l’influx nerveux et liens entre innervations somatique et autonome

Les fibres afférentes et efférentes des systèmes nerveux somatique et autonome sont reliées au système nerveux central, permettant à celui-ci de traiter les informations reçues de la région génitale et d’agir sur celle-ci.  En particulier, les informations sensitives somatiques sont transmises à l’hypothalamus et à l’aire génitale du cortex somato-senstif, et la diffusion de l'excitation sexuelle comme la réponse orgasmique sont modulées (inhibées ou favorisées) par des processus cognitifs pris en charge par plusieurs régions du cortex cérébral. Des structures sous-corticales / limbiques du cerveau sont également impliquées. Le ressenti en termes de plaisir – ou déplaisir – conscient est toujours dépendant de processus cérébraux.

Cependant, tout ne passe pas par le cerveau. Ainsi, des afférences génitales passant par le nerf pudendal peuvent provoquer des arcs réflexes qui via des centres nerveux de la moelle épinière, provoquent la contraction des muscles striés ischio-caverneux et bulbo-spongieux. Par ailleurs, les systèmes nerveux somatique et autonome sont liés. Des communications ont ainsi été décrites entre le nerf dorsal du clitoris et le nerf caverneux, à l’endroit où celui-ci pénètre dans le corps du clitoris.

Rôle clé du clitoris dans le plaisir sexuel

Rien n’indique l’existence d’une innervation sensitive du vagin (ou de toute autre partie du corps) qui soit comparable à celle du clitoris. Dans l’état actuel des connaissances, il est raisonnable de faire l'hypothèse que la zone érogène primaire se situe chez une femme au niveau du gland du clitoris, et dans une certaine mesure au niveau du corps du clitoris et de la jonction des bulbes.

La stimulation érogène primaire peut se faire soit directement au niveau du gland, soit au niveau de la partie distale du corps du clitoris à travers son capuchon, soit encore par l’intérieur du vagin, à proximité de son orifice, par pression au niveau de la base du corps du clitoris. Cette stimulation peut aussi être plus indirecte. Ainsi, la compression des piliers exercée par la contraction des muscles ischio-caverneux, celle des bulbes exercée par la contraction des muscles bulbo-spongieux, de même que la compression des bulbes (voire des piliers) par une pénétration, chassant dans tous les cas du sang vers le corps du clitoris, peuvent y participer.

Chez les femmes de même que chez les hommes, des zones érogènes secondaires peuvent se développer au fil du temps dans diverses autres parties du corps, de façon très variable selon le vécu des personnes.

 

Embryological origin of the external genitalia

Contrairement aux voies génitales, qui se développent à partir de deux structures différentes (canaux de Müller pour les voies féminines, canaux de Wolff pour les masculines), les organes génitaux externes humains dérivent de structures uniques indifférenciées. Un embryon de sept semaines possède ainsi un sinus uro-génital, bordé par des replis urétraux (ou plis uro-génitaux) qui sont eux-mêmes bordés par des bourrelets génitaux (ou plis labio-scrotaux), et un tubercule génital (ou phallus) situé à l’extrémité ventrale de ce sinus.

Sauf rares exceptions, l’embryon a vu ses gonades se différencier en testicules à partir de la 8ème semaine s’il est porteur d’un chromosome Y et en ovaires dans le cas contraire. C’est vers la 10ème semaine de développement que les organes génitaux externes commencent à se différencier soit dans un sens masculin, sous l’action des androgènes en principe produits par les testicules, soit dans un sens féminin en l’absence d’androgènes.

Lorsque tous les facteurs biologiques sont habituels, chez un fœtus non porteur de testicules le tubercule génital devient l’appareil érectile féminin. Les replis uro-génitaux restent ouverts et deviennent les petites lèvres, et les bourrelets génitaux fusionnent uniquement à leurs deux extrémités et deviennent les grandes lèvres. L’orifice du sinus uro-génital devient le vestibule vulvaire, dans lequel viennent s’ouvrir le vagin et l’urètre.

 

Lorsque tous les facteurs biologiques sont habituels, chez un fœtus porteur de testicules le tubercule génital devient l’appareil érectile masculin. Une gouttière se creuse à sa face antérieure, et les replis uro-génitaux qui la bordent se rejoignent pour former la partie terminale de l’urètre, qui traversera le pénis pour déboucher en principe à son extrémité. Les bourrelets génitaux fusionnent également pour devenir le scrotum (les bourses), où les testicules migreront ensuite.

La possession de certaines variantes génétiques peu communes, de même que l’exposition à un milieu hormonal inhabituel, peuvent conduire au développement d’organes génitaux externes ayant un aspect intermédiaire entre ces deux formes canoniques. Ces situations correspondent à un sous-ensemble de ce qu’on appelle l’intersexuation. Elles ne s’accompagnent en principe d’aucun dysfonctionnement de l’appareil érectile ou d’anomalie de la sensibilité génitale. En revanche, les interventions chirurgicales effectuées sur les personnes concernées afin de conférer à leurs organes génitaux externes une forme jugée socialement plus convenable peuvent lourdement handicaper leur fonction sexuelle.

 

Homology of the female and male forms of the external genitalia and related structures

Du fait de l’origine commune des organes génitaux externes et des structures adjacentes chez tous les êtres humains, on peut établir une homologie entre ces structures telles qu’elles se présentent chez une femme typique et telles qu’elles se présentent chez un homme typique. Le tableau ci-dessous présente une synthèse des principales structures concernées.

Page anat_tableau homologie.png

En particulier, le gland du pénis est homologue à celui du clitoris, les corps caverneux du pénis (formant également deux piliers fixés aux os ischio-pubiens avant de se rejoindre pour former le corps du pénis) sont homologues à ceux du clitoris, et son corps spongieux se prolongeant en forme de bulbe entre les piliers est homologue aux bulbes vestibulaires. 

Sur le plan histologique, la différence notable entre le clitoris et le pénis est que le gland de ce dernier est constitué d'un tissu spongieux pleinement développé (prolongeant le corps spongieux), ce qui n’est pas le cas du gland du clitoris.

Sur le plan fonctionnel, le pénis se distingue de l’organe bulbo-clitoridien par son association à l’urètre : il est également impliqué dans le transport de l’urine et celui des gamètes, alors que l’organe bulbo-clitoridien n'a pas d'autre fonction connue qu'érogène et orgasmogène.