Part Three: Male Sexual Anatomy, Sexual Response, and Changes in Sexual Function in Middle Age

◇A Guide to Caring for Your Husband's Health as a Good Wife◇

Previous articleBAO JIAN ZHI SHI

Health knowledge

Male sexual anatomy and sexual response

The male internal genitalia include the testes, epididymis, vas deferens, ejaculatory ducts, seminal vesicles, prostate gland, and bulbourethral glands. The testes are the male reproductive glands; the epididymis, vas deferens, and ejaculatory ducts are the conduits for transporting reproductive cells; the seminal vesicles, prostate gland, and bulbourethral glands are accessory glands, and the fluids they secrete contribute to the composition of semen. The external genitalia include the seminal vesicles and penis.

The penis is the primary sexual organ for adult men during sexual intercourse. It consists mainly of two corpora cavernosa on the dorsal side, beneath which lies the corpus spongiosum, through which the urethra passes. The glans penis (bald head) has an extremely rich nerve supply and is highly sensitive, serving as the center of pleasure during sexual intercourse and a key site for male sexual response. The skin of the penis is thin, with loose connective tissue beneath, exhibiting significant elasticity. The skin covering the glans penis is called the foreskin.

The corpora cavernosa of the penis is composed of an irregular network of cavernous blood vessels. During sexual arousal, these vessels become engorged with blood, causing the penis to thicken, lengthen, and harden-a phenomenon known as penile erection. An erection is maintained when the rate of arterial blood inflow equals the rate of venous return. If venous outflow exceeds arterial inflow, the erection subsides, and the penis returns to its natural resting state. The vascular factors contributing to erection are controlled by nerve impulses, which in turn are controlled by the brain's consciousness. Therefore, neuropsychological factors, as well as vascular and nerve factors, all affect penile erectile function. If the foreskin remains completely covered by the glans penis during erection and cannot be retracted, this is called phimosis. Phimosis can lead to the accumulation of a dense layer of smegma, which can cause penile cancer in men and cervical cancer in women; therefore, phimosis requires surgical treatment. If, during erection, the foreskin completely covers the glans penis but can be retracted, this is called redundant foreskin. If regular cleaning is maintained, surgery may not be necessary.

The scrotum is a skin sac that houses the testicles. The scrotal skin is elastic and capable of regulating its internal temperature. The temperature inside the scrotum can generally be maintained below 37°C, which is beneficial for sperm development. Wearing tight pants for extended periods or prolonged hot sitz baths can cause the scrotum to overheat, which is detrimental to sperm growth. The testicles are composed of two main types of functional cells: interstitial cells, which produce androgens (mainly testosterone), promoting libido and sexual function; and spermatogonia, which develop into sperm. Mature sperm will be released spontaneously, even without sexual intercourse, through nocturnal emissions. Semen consists of prostatic fluid, seminal vesicle fluid, and sperm.

Male sexual arousal is often triggered by erotic stimulation, especially visual stimulation (seeing female genitalia, naked women, or sexual intercourse). Males are more sensitive to visual stimulation than women. Initially, this manifests as an increased penis size and girth, accompanied by erection. This is the first stage of arousal. As it progresses, the glans penis enlarges and darkens in color, and the testicles increase in size by approximately 50% due to engorgement. Contraction of the cremaster muscle elevates the testicles, and a few drops of clear mucus are secreted from the urethral opening for lubrication. This is the second stage, the sustained engorgement stage. Once the threshold for orgasm is reached or exceeded, two reflexes occur. First, the prostate, vas deferens, and seminal vesicles contract, creating an uncontrollable preparation for ejaculation. Then, the corpus spongiosum, the muscles at the base of the penis, and the perineal muscles rhythmically contract, expelling semen from the urethra. This is typically marked by 3-4 contractions, each lasting 0.8 seconds. The contractions then weaken, and the intervals increase, simultaneously producing extreme pleasure. This is the third stage, the orgasmic ecstasy stage. After the orgasm, penile erection gradually subsides within 5-10 seconds, fully returning to the pre-coital state in about 30 minutes, followed by a refractory period of varying length. This is the fourth stage, the resolution phase.

What changes occur in the sexual function of middle-aged men?

◎Prolonged penile erection time: Middle-aged men's penises no longer erect as easily as young men's. Only after receiving sufficiently effective sexual stimulation can a middle-aged man's penis achieve an erection, which requires increasing foreplay before intercourse.

◎Reduced penile erection hardness: Middle-aged men's penile erection is not as good as that of young men, but they can still successfully insert their penis into the vagina to complete sexual intercourse.

◎Weakened ejaculation force: Due to decreased nerve reflexes and muscle contraction, middle-aged men have weaker ejaculation force than younger men, meaning the ejaculation distance is shorter, and sometimes the semen seems to flow out of the urethra.

◎Prolonged intercourse duration: Middle-aged men tend to have longer intercourse durations, which is an advantage in their sex life, making it easier for them to reach orgasm simultaneously with their partners.

◎Rapid penile flaccidity: After orgasm, the penis flaccidizes relatively quickly, but this does not affect sexual intercourse.

◎Prolonged refractory period: This refers to a prolonged interval between penile erections during two sexual encounters.

◎Monotonous Sexual Life: A monotonous and dull sexual life leads to a loss of interest in intercourse. After years of living together, both partners become intimately familiar with each other, and the wife may have lost her stimulating effect on the middle-aged man. Meanwhile, middle-aged women may be preoccupied with housework or social activities and may not show sexual interest or attention to their husbands. This obvious rejection can be particularly hurtful to the middle-aged man's psyche.

◎The effects of fatigue: Fatigue is a significant factor in decreased male libido. Both mental and physical fatigue can reduce male sexual tension, but the former is more pronounced.

◎Focus on career: Middle age is the peak of a man's career. Excessive dedication to his career or setbacks in his career can reduce his interest in sex.

◎Impact on the body and disease: Middle-aged and elderly people are like machines that have been running for a long time, and are more prone to problems than young people.

◎Fear of sexual aging: When middle-aged and elderly people experience sexual dysfunction, some simply ignore it, believing it to be an inevitable result of aging.

◎Overeating and excessive drinking: Overeating and excessive drinking in middle-aged and elderly people tend to cause inhibitory tension.