STRUCTURE and FUNCTION of MALE REPRODUCTIVE REPRODUCTIVE SYSTEM STRUCTURE and FUNCTION of MALE REPRODUCTIVE

See Figure 21-14 on pg. 460

TESTES AND epididymis Testes Found in scrotum Size of small egg Made up of 250 lobules, each with coiled seminiferous tubules Epididymis Collection of tubes above the testes Connect the testes with the vas deferens See Figure 21-15 on pg. 460

Vas deferens and scrotum Runs from epididymis to ejaculatory duct Seminal vesicles connect to vas deferens Ejaculatory duct connects vas deferens with urethra Scrotum Sac of skin that contains testes

Penis, prostate gland, and bulbourethral glands Contains erectile tissue End covered by foreskin – loose fitting skin Prostate Gland Surrounds beginning of urethra Size and shape of chestnut Bulbourethral glands Located on either size of prostate below prostate

TESTES Produce male gametes (spermatozoa) Produce male sex hormone – testosterone Inside, each lobule contains coiled seminiferous tubules where sperm develop In embryo, testes formed in the abdomen and during the last 3 months, migrate into scrotum

Epididymis – where sperm are stored Vas Deferens – serves as a passageway for sperm from epididymis to ejaculatory duct Scrotum – serves as container for testes

PENIS Contains erectile tissue Organ of copulation Tip of penis covered with foreskin, which is often removed during circumcision

Prostate Gland – secretes a fluid that enhances sperm motility and adds fluid to semen Bulbourethral glands – add alkaline secretion to semen that helps sperm live longer Infertility – lack of conception due to fallopian tube damage, low sperm count, hormone imbalance, and other disorders

ERECTION AND EJACULATION Urethra has dual role: excretion of urine and to expel semen Erection caused when erectile tissue fills with blood Ejaculation expels semen Impotence – unable to copulate (hold an erection)