Accessory Male Organs Add the Semen

The semen is a thick, milky, sugar-rich, very basic fluid that suspends (floats or holds up) the spermatozoa and gives them nutrition. When the male has an orgasm (OR-gaz-um), he is literally ''swollen and excited.'' He ejaculates spermatozoa suspended in a fluid of semen. The stored spermatozoa are actively sucked out of the epididymis by strong peristalsis (ringlike muscular contractions) of the walls of the vas (VAHS) deferens (DEF-er-enz).

The vas deferens is named for its function as a ''carrying away'' (deferens) ''vessel'' (vas). However, the vas deferens is not really a blood vessel at all. It is alternately called the ductus (DUCK-tus) deferens or ''carrying away duct.'' During male orgasm, the walls of the ductus deferens powerfully and rhythmically constrict or narrow. This negative pressure (suction) event draws the stored spermatozoa out of the epididymis, carrying them over the top of the urinary bladder, and down into the ejaculatory (ee-JACK-you-lah-tor-ee) duct. This ejaculatory duct is just a short, elbow-curved linkage to the urethra. The urethra goes all the way through the penis, and ends at the same hole where a man urinates - the external urethral orifice.

Semen is added to the spermatozoa from a number of accessory male reproductive organs. These organs include the two seminal (SEM-ih-nal) vesicles, the two bulbourethral (BUL-boh-you-REE-thral) glands, and the single prostate (PRAH-state) gland. The seminal vesicles store the ''semen'' (semin). The bulbourethral glands (Figure 15.4) are like two tiny ''bulbs'' attached to the sides of the ''urethra.'' And the prostate gland is a large, walnut-shaped body that ''stands'' (stat) just ''before'' (pro-) the urethra.

0 0

Post a comment