MALE PHYSIOLOGY
Whether or not you ever become a father, the male reproductive system is designed to help you do just that. Your male sex organs produce, store and deliver millions of tadpole-shaped spermatozoa (‘sperm’), each primed to fertilise a female’s egg after sex.
Many of the most dramatic physical and emotional changes you experience as you become an adult are driven by chemicals that your glands and other tissues produce, called male sex hormones or androgens. Your hypothalamus and your pituitary gland, at the base of your brain, control the release and levels of these hormones. Testosterone, which is mostly produced in the testes, is the most potent androgen in men.
PubertyPuberty, the transition from child to sexually mature adult, usually takes between about 2 to 5 years. A growth spurt that could kick in between the ages of 10 and 16 may be the first outward sign for boys. Testosterone secretion surges, stimulating the growth of the beard, body hair, bone, muscle and prostate gland (your prostate produces some of the fluid that mixes with sperm when you ejaculate). Testosterone also fuels powerful emotional urges, most notably your sex drive and aggression. Sperm journeyTestosterone also fosters the development of your sex organs, including your testes, where sperm is produced. From the testes, sperm move through the epididymis, which is five metres of tightly coiled tubing tucked up behind your testes. In the epididymis, sperm develop the essential ability to move or swim (become ‘motile’). They are stored in the epididymis until you have an erection. In very simple terms, when you have an orgasm, muscle contractions move the sperm along a series of ducts where they collect fluids that mingle to become semen. The sperm-bearing semen is pushed out through the penis during ejaculation.
More changesDuring puberty, as your glands become active, pumping out more hormones, you may grow:– more muscular– taller, broad-shouldered and heavier – a deeper voice – pubic hair, underarm hair and chest hair– more sweaty– oilier skin and pimples.
Along with the rest of your body, your penis and testes grow bigger and you get erections – your penis gets hard, sometimes when you least expect it. With puberty, as your sperm production begins you might ejaculate when you get an erection, releasing semen. Sometimes this happens while you sleep; it’s called a ‘wet dream’. It’s a normal sign that the plumbing in your reproductive system works.
After age 40, male testosterone levels fall very gradually. In some older men, testosterone levels get too low, causing health problems. Older men are also more likely to suffer from conditions such as prostate disease and erectile dysfunction. Erectile dysfunction can affect young men too, but usually due to different causes.
