1. The Male Reproductive System

2. The Reproductive System
Gonads—primary sex organs
Testes in males
Ovaries in females
Gonads produce gametes (sex cells) and secrete hormones
Sperm—male gametes (Spermatogenesis)
Ova (eggs)—female gametes
(Oogenesis)

3. Functions
1. Produces, nurtures and transports gametes (ova/sperm)
2. Secrets hormones
3. Provide a means for fertilization

4. Divisions of the Male Reproductive System
Testes
Duct System
Accessory Glands
External Genitalia
We will discuss each of these in more detail

5. A. Testes
Each testis is surrounded by a membrane. This membrane extends into each testis forming partitions that divide the testis into approximately 250 compartments, or lobules.

6. Seminiferous tubules 1-4 found in each lobule tightly coiled
sperm-forming factories

7. Rete testis
*May or may not be considered an actual part of the duct system depending on the reference being used
Network of ducts (channels)
Take immature sperm cells from seminiferous tubules to epididymus

8. 2 Types of Cells within the testis
Interstitial cells: produce androgens (male hormones) such as testosterone
Spermatogenic: sperm-producing cells

9. B. Duct System Epididymis Ductus (vas) deferens Ejaculatory Duct
Urethra

10. 1. Epididymis Comma-shaped, tightly coiled tube (20 ft)
Found on the superior part of the testis along the posterior lateral side
Functions to mature and store sperm cells (at least 20 days)
Muscles in the epididymis walls move sperm to the vas deferens

11. 2. Ductus Deferens (Vas Deferens)
Carries sperm from the epididymis to the ejaculatory duct
Passes over the bladder
Moves sperm by peristalsis

12. Vasectomy
cutting of the ductus deferens at the level of the testes to prevent transportation of sperm

13. 3. Ejaculatory Duct
Unites the ductus deferen with the urethra

14. 4. Urethra
Extends from the base of the urinary bladder to the tip of the penis
Carries both urine and sperm
Sperm enters from the ejaculatory duct

15. Figure 16.2b

16. C. Accessory Organs 1. Seminal vesicles 2. Prostate
3. Bulbourethral glands (Cowper)

17. 1. Seminal Vesicles Located at the base of the bladder
Produces a thick, yellowish secretion (60% of semen)
Fructose (sugar)
Vitamin C
Prostaglandins (hormones)
Other substances that nourish and activate sperm

18. 2. Prostate Encircles the upper part of the urethra
Secretes a milky fluid
Helps to activate sperm
Enters the urethra through several small ducts

19. 3. Bulbourethral Glands Pea-sized gland inferior to the prostate
Produces a thick, clear mucus
Cleanses the urethra of acidic urine
Serves as a lubricant during sexual intercourse
Secreted into the penile urethra

20. Figure 16.2a

21. Semen Mixture of sperm and accessory gland secretions
Advantages of accessory gland secretions
Fructose provides energy for sperm cells
Alkalinity of semen helps neutralize the acidic environment of vagina
Semen inhibits bacterial growth
Elements of semen enhance sperm motility

22. D. External Genitalia
1. Scrotum
2. Penis

23. 1. Scrotum Divided sac of skin outside the abdomen
Maintains testes at 3°C lower than normal body temperature to protect sperm viability
Muscles move testes up toward body or lower away from body

24. 2. Penis Delivers sperm into the female reproductive tract
Regions of the penis
Shaft
Glans penis (enlarged tip)
Prepuce (foreskin)
Folded cuff of skin around proximal end
Often removed by circumcision
Internally there are three areas of spongy erectile tissue around the urethra
Erections occur when this erectile tissue fills with blood during sexual excitement