Penile-Vaginal Intercourse

Penile-vaginal intercourse, also known as vaginal intercourse or vaginal sex, is a form of penetrative sexual intercourse in human sexuality. In this act, an erect penis is inserted into the vagina, often culminating in ejaculation and orgasm.

Physiological Mechanisms

Erection

An erection is a physiological process that allows the penis to become engorged with blood and sufficiently rigid for penetration. The erection process involves complex interactions between the nervous system, vascular system, and hormonal signals. Notably, human males achieve erections without the aid of a penis bone, a structure found in many other mammals.

Vaginal Lubrication

Vaginal lubrication is essential for painless and pleasurable thrusting movements during intercourse. Lubrication is produced by the Bartholin's glands and the vaginal epithelium. Adequate lubrication reduces friction, making intercourse more comfortable for both partners.

Sensory Stimulation

During intercourse, the sensory nerve terminals located in the penile skin, prepuce, and glans receive continuous mechanical stimulation. Similarly, the vaginal walls contain nerve endings that respond to the tactile stimuli provided by penile thrusting.

Penile Size and Sensitivity

Variation in penile size and sensitivity can significantly affect the perception of stimuli during intercourse. Studies have shown that the average intravaginal ejaculatory latency time (IELT) is approximately five minutes, although this duration can vary among individuals.

Psychophysiological Aspects

The psychophysiological aspects of penile-vaginal intercourse involve a complex interplay between emotional intimacy, sexual arousal, and haptic feedback. Both male and female partners experience a range of sensory and emotional responses during and after intercourse, contributing to sexual satisfaction and emotional bonding.

Female Orgasm

The female orgasm during penile-vaginal intercourse is often associated with clitoral stimulation, although some women can achieve orgasm through vaginal penetration alone. The clitoris has a high concentration of nerve endings, making it a critical structure for female sexual pleasure.

Male Orgasm and Ejaculation

The male orgasm is typically accompanied by ejaculation, where semen is expelled through the urethra. Ejaculation is controlled by the sympathetic nervous system and involves rhythmic contractions of the pelvic muscles.

Sexual Positions

Various sexual positions can be employed during penile-vaginal intercourse, each offering different angles and depths of penetration. Some positions may also facilitate enhanced clitoral or G-spot stimulation.

Common Positions

Missionary Position: The male partner lies on top of the female partner.
Cowgirl Position: The female partner sits or kneels on top of the male partner.
Doggy Style: The male partner penetrates the female partner from behind.