To state the obvious: men have no organ equivalent to the vagina. [i] By considering how human sexual response must have evolved, we can start to understand that it is much more likely that female responsiveness arises from the anatomy that women have evolved in common with men than that it arises from the anatomy that they have evolved independently of men.
The female external genitalia (clitoris and labia) are anatomically equivalent to the male (penis and testicles). They are similarly positioned. The clitoris can be clearly identified as the organ that is equivalent to the penis because both organs develop from identical structures in the embryo. If someone can choose to enjoy orgasm, they must also be able to achieve it by themselves. The penis and clitoris are easily reached by the hands so that stimulation is possible regardless of whether a partner is available.
The defining characteristic of a sex organ is that it is capable of producing the response of orgasm. When stimulated, in conjunction with a mental focus on psychological stimuli of an erotic nature, the organ can give rise to muscle contractions in the lower pelvic area and highly pleasurable sensations in the brain. Stimulation that leads to orgasm involves a technique that massages the erectile organ (specifically the blood flow within it). Ideally, we control our own stimulation because only we know the state of our own mind and how to best synchronise genital stimulation to optimise the mental impact of orgasm (satisfaction obtained from sexual release).
The sex organ is the only organ that triggers an orgasmic response. Unlike the penis, the clitoris has no other function apart from that of being a sex organ. The clitoris is the only female erectile organ. Increased blood flow (in middle-aged women) causes the internal clitoral organ to swell. A woman’s sex organ (the clitoris) is separate from her internal reproductive anatomy (ovaries, uterus and vagina). A man’s sex organ (the penis) is also separate from his internal reproductive anatomy (testes and male glands).
The pleasures of orgasm and ejaculation motivate men to engage in mating activity whereby a woman is impregnated. There is no similar motivation for a woman to orgasm. Even today, the clitoris is often omitted from any description of women’s sexual anatomy. The clitoris, as a remnant of what becomes the penis in a man, has masculine connotations. It is considered a redundant aspect of women’s anatomy, which for most women it evidently is. This is because the two sexes have evolved different responses and behaviours to maximise the chances of successful reproduction.
[i] The vagina … is not matched by any functioning structure in the male, but it is of minimum in contributing to the erotic responses of the female. It may even contribute more to the sexual arousal of the male than it does to the arousal of the female. (Alfred Kinsey)
Excerpt from Women’s Sexual Behaviours & Responses (ISBN 978-0956-894717)
