strong6_ppt_ch04
- 1. Chapter Four Male Sexual Anatomy, Physiology, and Response
- 2. Male Sex Organs: What Are They for? Sex organs serve a reproductive function Also serve other functions: Bringing pleasure to self Giving pleasure to others May serve to attract potential sexual partners Sharing of genital sexuality can play a bonding role in relationships
- 3. External Structures The penis The scrotum
- 4. The Penis Penis: from Latin word for tail organ through which sperm and urine pass Three main sections: Root: attaches penis within the pelvic cavity Shaft: contains 3 parallel columns of erectile tissue Corpora cavernosa: 2 columns along the front surface Corpus spongiosum: runs beneath corpora cavernosa, also forms the glans
- 5. The Penis Glans penis: head of penis; most sensitive Corona: rim at base of the glans Frenulum: on underside of penis; triangle of sensitive skin Foreskin: sleeve-like covering of the glans Circumcision Urethra : a tube that transports urine and semen When penis erect, urinary duct is blocked
- 6. The Penis: Myths Penis size not linked to body size or weight, muscular structure, race or ethnicity or sexual orientation No relationship between penis size and ability to have sexual intercourse or satisfy a partner
- 7. The Scrotum A pouch of skin that holds the two testicles Scrotum skin more heavily pigmented Sparsely covered with hair Divided in the middle by a ridge of skin Testicle temperature control: 93 °F
- 8. Internal Structures Testes: Two major functions: sperm and hormone production Shaped like olives; 1.5” long and 1” diameter. Size and weight decrease as men age Not usually symmetrical in the way they hang Suspended by spermatic cord Within each testicle, there are about 1000 Seminiferous tubules: Production of sperm takes place in these tubes
- 9. Internal Structures Epididymis C shaped structure on the back of the teste Sperm mature in vas deferens Vas Deferens The ducts that carry sperm from testicles to urethra for ejaculation Vas deferens joins the ejaculatory duct within prostate gland
- 10. Internal Structures Seminal vesicles Secrete fluid that makes up 60% of semen Prostate gland Secretes fluid that makes up 30-35% of semen Can be stimulated in anal play Cowper’s (bulbourethral) glands Secrete thick clear mucus prior to ejaculation Urethra
- 11. Other structures Breasts Anus Buttocks Rectum
- 12. Male Sexual Physiology Production of hormones Spermatogenesis
- 13. Male Reproductive Hormones Testosterone Acts on seminiferous tubules to produce sperm Regulates sex drive Is responsible for development of secondary sex characteristics in puberty Influences growth of bones and muscle mass
- 14. Spermatogenesis Ongoing process from puberty onward Sperm produced within seminiferous tubules of testicles (64-72 days) Several 100 million sperm produced daily 20 days for sperm to travel through epididymis During this time they become fertile and motile Upon ejaculation, sperm expelled through urethra by muscular contractions
- 15. Male Sexual Response Erection Blood vessels expand and increase blood in penis Veins that normally carry blood out are compressed, leading to engorgement of penis Secretions from Cowper’s glands appear at tip
- 16. Ejaculation and Orgasm Emission stage Sperm sent into vas deferens Rhythmic contractions begin Feeling of ejaculatory inevitability Expulsion stage Rapid contractions Semen spurts from urethral opening Orgasm Intensely pleasurable physical sensations that usually accompany ejaculation Followed by refractory period
- 17. Summary Male sex organs Sexual physiology Sexual response