THE QUICK GUIDE TO THE REPRODUCTIVE SYSTEM
Now, let’s take a quick look at the reproductive system:
Sperm and testosterone, the male hormone, are made in the testicles. Testosterone is the substance that makes the prostate grow at puberty; it also stimulates the prostate to manufacture its secretions. Sperm travel from the testicles to the twisting, winding epididymis, a convoluted “greenhouse” where they mature.
The epididymis connects to the vas deferens, a hard, muscular cord that winds all the way from the scrotum into the body and down to the back of the prostate. At this point, the seminal vesicles, which produce 70 percent of the fluid for semen, connect to the vas deferens to form the ejaculatory ducts, which run into the center of the prostate. When a man ejaculates, sperm rocket from the epididymis through the vas deferens and out of the ejaculatory duct, where they’re mixed with the fluids from the prostate and seminal vesicles.
To make sure that the semen doesn’t “back up” into the bladder, a muscular valve slams shut in the bladder neck, forcing the semen out the urethra in the penis. Soon after ejaculation, the semen coagulates. A substance called prostate-specific antigen (PSA), which is made by the prostate, then acts on the semen, causing it to become liquid again.
To understand what can go wrong with the prostate, it will probably help to study the illustrations in this chapter and the rest of the book (the illustration in the Glossary shows the male urinary and reproductive systems together). The prostate encircles the urethra like a fist holding a straw—therefore, when its transition zone enlarges, in benign prostatic hyperplasia (BPH), this compresses the urethra and causes urinary problems. Finally, by understanding how PSA is secreted from ducts in the prostate, you’ll be able to see why PSA levels increase when these ducts become obstructed, as they do in prostate cancer.
*18\201\8*
Related Posts:
Tags: Erectile Dysfunction, Men’s Health