Supporting an anatomical relationship between the clitoris and vagina is a study published in 2005, which investigated the size of the clitoris; Australian urologist Helen O'Connell, described as having initiated discourse among mainstream medical professionals to refocus on and redefine the clitoris, noted a direct relationship between the legs or roots of the clitoris and the erectile tissue of the clitoral bulbs and corpora, and the distal urethra and vagina while using magnetic resonance imaging (MRI) technology. [101] [102] While some studies, using ultrasound, have found physiological evidence of the G-spot in women who report having orgasms during vaginal intercourse, [89] O'Connell argues that this interconnected relationship is the physiological explanation for the conjectured G-Spot and experience of vaginal orgasms, taking into account the stimulation of the internal parts of the clitoris during vaginal penetration. "The vaginal wall is, in fact, the clitoris," she said. "If you lift the skin off the vagina on the side walls, you get the bulbs of the clitoris–triangular, crescental masses of erectile tissue." [16] O'Connell et al., having performed dissections on the female genitals of cadavers and used photography to map the structure of nerves in the clitoris, made the assertion in 1998 that there is more erectile tissue associated with the clitoris than is generally described in anatomical textbooks and were thus already aware that the clitoris is more than just its glans. [103] They concluded that some females have more extensive clitoral tissues and nerves than others, especially having observed this in young cadavers compared to elderly ones, [103] and therefore whereas the majority of females can only achieve orgasm by direct stimulation of the external parts of the clitoris, the stimulation of the more generalized tissues of the clitoris via vaginal intercourse may be sufficient for others. [16]

Moore, Lisa Jean; Clarke, Adele E. (April 1995). "Clitoral Conventions and Transgressions: Graphic Representations in Anatomy Texts, c1900-1991". Feminist Studies. 21 (2): 255–301. doi: 10.2307/3178262. JSTOR 3178262.

The G-spot is analogous to the base of the male penis and has additionally been theorized, with the sentiment from researcher Amichai Kilchevsky that because female fetal development is the "default" state in the absence of substantial exposure to male hormones and therefore the penis is essentially a clitoris enlarged by such hormones, there is no evolutionary reason why females would have an entity in addition to the clitoris that can produce orgasms. [107] The general difficulty of achieving orgasms vaginally, which is a predicament that is likely due to nature easing the process of childbearing by drastically reducing the number of vaginal nerve endings, [108] challenge arguments that vaginal orgasms help encourage sexual intercourse to facilitate reproduction. [109] [110] Supporting a distinct G-spot, however, is a study by Rutgers University, published in 2011, which was the first to map the female genitals onto the sensory portion of the brain; the scans indicated that the brain registered distinct feelings between stimulating the clitoris, the cervix and the vaginal wall–where the G-spot is reported to be–when several women stimulated themselves in a functional magnetic resonance (fMRI) machine. [105] [111] Barry Komisaruk, head of the research findings, stated that he feels that "the bulk of the evidence shows that the G-spot is not a particular thing" and that it is "a region, it's a convergence of many different structures". [109] Vestigiality, adaptionist and reproductive views Goldmeier, D; Leiblum, SR (2006). "Persistent genital arousal in women – a new syndrome entity". International Journal of STD & AIDS. 17 (4): 215–216. doi: 10.1258/095646206776253480. PMID 16595040. S2CID 38012437. Sexological, medical, and psychological debate has focused on the clitoris, [5] and it has been subject to social constructionist analyses and studies. [6] Such discussions range from anatomical accuracy, gender inequality, female genital mutilation, and orgasmic factors and their physiological explanation for the G-spot. [7] Although, in humans, the only known purpose of the clitoris is to provide sexual pleasure, whether the clitoris is vestigial, an adaptation, or serves a reproductive function has been debated. [8] Social perceptions of the clitoris include the significance of its role in female sexual pleasure, assumptions about its true size and depth, and varying beliefs regarding genital modification such as clitoris enlargement, clitoris piercing and clitoridectomy. [9] Genital modification may be for aesthetic, medical or cultural reasons. [9] Odile Fillod created a 3Dprintable, open source, full-size model of the clitoris, for use in a set of anti-sexist videos she had been commissioned to produce. Fillod was interviewed by Stephanie Theobald, whose article in The Guardian stated that the 3D model would be used for sex education in French schools, from primary to secondary level, from September 2016 onwards; [161] this was not the case, but the story went viral across the world. [162]

In mammals, sexual differentiation is determined by the sperm that carries either an X or a Y (male) chromosome. [17] The Y chromosome contains a sex-determining gene ( SRY) that encodes a transcription factor for the protein TDF (testis determining factor) and triggers the creation of testosterone and anti-Müllerian hormone for the embryo's development into a male. [18] [19] This differentiation begins about eight or nine weeks after conception. [18] Some sources state that it continues until the twelfth week, [20] while others state that it is evident by the thirteenth week and that the sex organs are fully developed by the sixteenth week. [21] The clitoris is the human female's most sensitive erogenous zone and generally the primary anatomical source of human female sexual pleasure. [2] In humans and other mammals, it develops from an outgrowth in the embryo called the genital tubercle. Initially undifferentiated, the tubercle develops into either a penis or a clitoris during the development of the reproductive system depending on exposure to androgens (which are primarily male hormones). The clitoris is a complex structure, and its size and sensitivity can vary. The glans (head) of the human clitoris is roughly the size and shape of a pea and is estimated to have 8,000, and possibly more than 10,000, sensory nerve endings. [3] [4] During sexual arousal, the clitoris and the whole of the genitalia engorge and change color as the erectile tissues fill with blood ( vasocongestion), and the individual experiences vaginal contractions. [75] The ischiocavernosus and bulbocavernosus muscles, which insert into the corpora cavernosa, contract and compress the dorsal vein of the clitoris (the only vein that drains the blood from the spaces in the corpora cavernosa), and the arterial blood continues a steady flow and having no way to drain out, fills the venous spaces until they become turgid and engorged with blood. This is what leads to clitoral erection. [12] [76] Gormley-Fleming, Elizabeth; Peate, Ian (2021). Fundamentals of Children and Young People's Anatomy and Physiology: A Textbook for Nursing and Healthcare Students. Wiley. p.307. ISBN 978-1-11961-924-6 . Retrieved 29 September 2023. Clitoraid launches 'International Clitoris Awareness Week' ". Clitoraid. 3 May 2013. Archived from the original on 28 January 2018 . Retrieved 8 May 2013.Drea, Christine M.; Weil, Anne (30 October 2007). "External genital morphology of the ring-tailed lemur (Lemur catta): Females are naturally "masculinized" ". Journal of Morphology. 269 (4): 451–463. doi: 10.1002/jmor.10594. ISSN 0362-2525. PMID 17972270. S2CID 29073999.