In the Discussion section of this paper [1], Yang et al. write: “The generalized vulvar engorgement that occurs with sexual arousal affects the vagina/vestibule, clitoris, labia minora, urethra, and bulbs.” The vestibular bulbs “are more appropriately named ‘clitoral bulbs’ ” . . . “Genital tissues in both males and females arise from the same embryological structures and thus are homologous.”

Fallopius, in 1561 (in the ‘Observationes Anatomicae’) provided the first detailed description of the deeper structures of the clitoris and stated, “This small part corresponds to the male penis.”[2]. The anatomy of the vestibular bulbs is presented in anatomy textbooks, and these structures are considered homologous to the single penile bulb in the male [3–5]. The vestibular bulbs anteriorly extend into the glans clitoridis with the female corpus spongiosum (pars intermedia) [4,5]. This anatomical structure was described by Pozzi for the first time in 1884, and given the name briglia mascolina del vestibolo (habenulae uretrales) [3,5]. The female corpus spongiosum is situated directly underneath the vulvar epithelium [6], and the vestibule corresponds to the dorsal surface of the male penile urethra [4,5,7]. The labia minora are normally joined and correspond to the ventral surface of the male corpus spongiosum and penile urethra [4–7]; the labia majora correspond to the scrotum: “The female vulva is the cleft representation of the male penis and scrotum”[6].

Recently the female bulbs have been recognized as parts of the clitoris and they should be preferably termed ‘bulbs of the clitoris’[8]. The female bulbs do not develop from the genital tubercle but from the urethral folds [4–7]; the bulbs do not belong to the clitoris, but, as in the male, to the female corpus spongiosum that is part of the female penis, and the correct anatomical term is ‘bulbs of the female penis’[7,9,10].

The ‘female penis’, similar to that in the male, is composed of two corpora cavernosa (they begin with the crura) and the female corpus spongiosum (glans, bulbs, corpus spongiosum or pars intermedia, vestibule and labia minora) [7,9,10]. The corpus spongiosum of the female urethra also exists [3,5], and can be considered part of the female penis [9,10]. The ‘G spot’ does not exist [10]; Grafenberg, in 1950, discovered no ‘G spot’, but reported the role of the urethra in female orgasm. Grafenberg also described some cases of urethral masturbation, female and male, and wrote “Analogous to the male urethra, the female urethra also seems to be surrounded by erectile tissues like the corpora cavernosa”.

There are also glandular structures within the spongy tissue surrounding the urethral lumen, but these glands are now defined as ‘female prostate’ (an anatomical structure described by de Graaf for the first time in 1672), with the same diseases as has the male prostate, including carcinoma, BPH and prostatitis [10].

This new anatomical terminology of the female vulva is important in sexology. The female orgasm, as in the male, is always caused by the female penis [7,9,10]. The female vagina has little sensitivity and the vaginal orgasm does not have a scientific basis, does not exist and was invented by Freud in 1905 [10]. The vagina is mainly a reproductive organ and its embryological origin in sexology is mistaken, in the extent to which it develops only from the urogenital sinus (as the male vagina, situated in the male prostate, with the same diseases as has the female vagina) with no contribution from the Müllerian ducts [3–5,10]. The vaginal orgasm that some women report is always caused by the surrounding erectile structures (female penis in erection), and the rhythmic muscle contractions that occur in the outer third of the vagina are caused by bulbocavernosus muscle, not puboccygeus muscle; the correct terms now used after years of anatomical study are ‘pubovaginalis muscle’ and ‘levator muscle of the prostate’, and ‘puborectalis muscle’[10]. Orgasm is a normal bodily function and all women should be able to achieve it, because all have a ‘female penis’. The glans, labia minora and vestibule contain free nerve endings and many sensory receptors, especially Krause-Finger and genital corpuscles, but also Pacini and Meissner corpuscles [3–5,7,10]. The female orgasm can also be caused with no vaginal lubrication, with no penis-vagina intercourse, and in all ages; male erection = engorgement of the female penis [10]: clitoral and bulbar engorgement, homologous to penile erection in the male, is a genital manifestation of female sexual arousal and is mediated by autonomic fibres [11]. Vaginal lubrication is a consequence of the blood engorgement that also occurs at the vaginal level [10]. The erection of the male and female penis occurs in three phases, i.e. latent, turgid, and rigid or muscular, but the absence in the clitoris of the subalbugineal layer between the erectile tissue and the tunica albuginea and of the subalbugineal venous plexus suggest that the clitoris does not achieve a rigidity similar to that of the penis [10]. Kegel exercises, in both males and females, are important for the perineal muscles and especially the superficial ones, the most important in sexology; the tonic contraction of ischiocavernosal muscles (muscle of erection) during erection is necessary for rigidity of the penis [10]. These muscles, as also the bulbocavernosus muscle (muscle of male ejaculation), are of the mixed type (even if histologically they are striated muscles), and they have a semiautomatic operation: the ischiocavernosal muscles, together with the bulbocavernosus muscle, during male erection introduces a continuous involuntary reflected hypertonic contraction, conclusive not only for the rigidity of the penis, but also for the maintenance of the erection. With Kegel exercises it is possible to train these two muscles [10]. A correct knowledge of the anatomy and physiology of the female sexual organs can also contribute to the struggle against female genital mutilation.

In conclusion, to describe the cluster of erectile tissues (clitoris, bulbs and pars intermedia, labia minora and vestibule, corpus spongiosum of the female urethra) responsible for female orgasm, the correct (and simple) anatomical term is ‘female penis’ and not ‘clitoris’ or other terms.