Dr. Ruth K. Westheimer - Sex For Dummies

When a germ cell undergoes meiosis, it forms two new cells, each of them having only half of the DNA code: 23 bits of genetic material (called chromosomes ) instead of the normal 46.

When a sperm teams up with a female egg, which also only has 23 chromosomes, their genetic materials intertwine, and the resulting baby ends up with a package containing a total of 46 chromosomes that is a mixture of both the mother’s and the father’s genetic material.

When the male germ cells divide, the sex chromosomes divide also. The male has one X and one Y chromosome; the female has two X chromosomes.

Whether the sperm that reaches the egg first has an X (female) or Y (male) chromosome determines whether the baby will be a girl or a boy.

All of you macho men out there may appreciate knowing one more thing about a spermatozoon (a single, fully developed sperm; spermatozoa is the plural): Not only can sperm move around on their own outside the body, but they’re also fully armed, like little guided missiles. Over the head of the sperm lies the acrosome , which is full of enzymes that help the sperm penetrate an egg if it should be so lucky as to meet one on its journey.

When they’re ready, the sperm leave the testes (another name for testicles) and enter the epididymis , which is a series of tiny tubes that lie on top of the testes. (For those of you into amazing statistics: If unfurled, these tubes would reach 60 feet in length.) During their journey through the epididymis, sperm learn to swim. They enter the epididymis with useless tails and leave it as little speed demons. (See the advice that practice makes perfect lies at the very heart of human life.)

If you go back to Figure 2-5, you see that the sperm’s next stop on their voyage is the vas deferens , a tube that ejects the sperm into the urethra , through which semen and urine pass. In the urethra, the sperm are mixed with fluids from the seminal vesicles and the prostate (which I discuss in more detail later in the “ The Prostate Gland” section); then they make their way out into the world through ejaculation.

The combination of these fluids and the sperm is called semen . The amount of semen ejaculated during orgasm is generally around a teaspoonful, though it varies depending on when the man last ejaculated. The semen is whitish in color, has a distinctive smell, and is thick when it first comes out. Sperm only comprise about 5 to 10 percent of the volume, but they are the only part of the semen that can cause pregnancy.

Just because your testicles look normal doesn’t mean that they are fully functioning. If a couple tries to conceive but can’t seem to do it, one of the first things that doctors look for is a problem with the man’s sperm. The most common problems are a low sperm count (which means that the man isn’t producing enough sperm) or the sperm he is producing lack sufficient motility, the ability to swim to the egg. The basis for the problems may be abnormal sperm production, which can be difficult to treat or can be as simple as changing from tighty whities to boxers because heat is known to decrease sperm count. Another cause can be a blockage somewhere along the line, which may be corrected through surgery.

Interestingly enough, most semen analysis is done by gynecologists , specialists in the female reproductive system. A gynecologist is usually the first person a woman consults when she has problems getting pregnant. Commonly, the gynecologist asks that the man’s sperm be analyzed. If the tests reveal a problem with the sperm, the man is sent to a urologist for further evaluation.

Despite the fact that some men adopt a tough-guy, macho image, the heart of their maleness, the testicles, is highly sensitive. The testicles are so sensitive that men may experience some pain down there just by thinking about the pain that occurs when their testicles are struck by an object.

If a boy has never had the sensations caused by a blow to the scrotum, then he may not see the need to wear a cup over his groin area when playing rough sports. But no man who has suffered this agony would hesitate for a minute to protect himself with a cup, especially because cups can prevent injury to the testes that may cause fertility problems later on. (For some odd reason, football players, who wear padding everywhere else, avoid taking any protective measures down there. That’s about the only factor you won’t hear discussed during all the coverage prior to the Super Bowl!)

Even though the testicles are easily accessible, most men don’t pay all that much attention to them (apart from trying to protect them from getting kicked — something fathers of toddlers who love slamming into Dad are well aware of). That can prove unfortunate, because testicular cancer can be deadly if you don’t find it in time. Although rare, testicular cancer most often appears in men from ages 15 to 35. In fact, it is the most common form of cancer in men in their 20s and 30s. Luckily, the disease is also easily curable — if a man finds it in time.

Because the testicles are outside the body and can be examined, men can easily feel testicular cancer if it is present. And the best news is that because the testicles are so accessible, men can spare themselves the trouble of going to a doctor for the examination (as we women must do with cervical cancer) by examining their testicles themselves.

Testicular cancer usually begins as a painless lump. The sooner you find such a lump, the better your chances of having it treated without any serious medical consequences. Begin checking for lumps in your teen years.

The best time to perform a self-exam is after a hot shower or bath because the warm water allows the scrotum to relax and the testicles to drop down. You can do the check while you’re sitting, standing, or lying down.

To check for lumps:

1 Gently take each testicle and roll it between your thumb and forefinger to see if you detect anything different about how it feels compared with last time.Your testicle should feel smooth and firm with a slight softness, a lot like a hard-boiled egg without the shell.

2 As a guide, compare your two testicles to each other.Remember, it’s normal for one testicle to be slightly larger than the other and/or one to hang lower than the other.

3 If you do find something that feels different, pick up the phone right away and make an appointment to see a urologist.

4 Do this test around the same time each month to get into the habit.

Remember that the epididymis sits on top of the testicle. Some men examining themselves for testicular cancer mistake it for a strange lump. They get a real fright before a doctor explains to them what it is. So what you need to have clear in your mind is that you are checking your testicle — the hard-boiled egg. The lumpy epididymis, which lies on top of the testicle, belongs there and is supposed to be lumpy but not tender.

Testicular cancer can hit any man, but men who had one or both undescended testicles at birth (see “ Making the descent” earlier in the chapter) are at higher risk. So if either or both of your testicles had not descended when you were born, make doubly sure that you perform this exam every month.