1. Male Reproductive System (pg 6)

2. Male Reproductive System (pg 6)
• Functions: Produce and transport sperm,
introduce sperm into female vagina, and
produce hormones responsible for
development of secondary male sex
characteristics

3. Testes
• Produce sperm

4. Testes
• Produce sperm
• Begin development high in abdominal cavity.
Around 2 months before birth, they descend
into the scrotum

5. Testes
• Produce sperm
• Begin development high in abdominal cavity.
Around 2 months before birth, they descend
into the scrotum
• Testes are around 3 degrees cooler than body
temperature. Necessary for production of
viable sperm.

6. Testes
• Produce sperm
• Begin development high in abdominal cavity.
Around 2 months before birth, they descend
into the scrotum
• Testes are around 3 degrees cooler than body
temperature. Necessary for production of
viable sperm.
• Cremaster muscle contracts when cold to
bring the testes closer to the body for warmth

7. Duct system
• Once produced in the testes, sperm move
through a series of ducts to reach the outside
of the body. The ducts are the
epididymis, ductus deferens, ejaculatory
duct, and urethra

8. Epididymis
• Long tube (6 meters). Tightly coiled to form
comma-shaped organ that sits on top of testes

9. Epididymis
• Long tube (6 meters). Tightly coiled to form
comma-shaped organ that sits on top of testes
• When sperm leaves testes, they are unable to
“swim” and incapable of fertilizing an egg

10. Epididymis
• Long tube (6 meters). Tightly coiled to form
comma-shaped organ that sits on top of testes
• When sperm leaves testes, they are unable to
“swim” and incapable of fertilizing an egg
• As sperm slowly move through the
epididymis, they mature and become fertile

11. Ductus deferens (vas deferens)
• Tube that carries sperm from the epididymis
to the ejaculatory duct

12. Ductus deferens (vas deferens)
• Tube that carries sperm from the epididymis
to the ejaculatory duct
• Vasectomy: surgical procedure that severs the
ductus deferens for birth control

13. Ejaculatory duct
• Ductus deferens joins duct from the seminal
vesicle to form a short ejaculatory duct

14. Ejaculatory duct
• Ductus deferens joins duct from the seminal
vesicle to form a short ejaculatory duct
• Passes through the prostate gland and into
the urethra

15. Urethra
• Passageway for urine and semen

16. Urethra
• Passageway for urine and semen
• 3 regions
1. Prostatic urethra: passes through prostate
gland. Receives fluids from ejaculatory duct
and prostate

17. Urethra
• Passageway for urine and semen
• 3 regions
1. Prostatic urethra: passes through prostate
gland. Receives fluids from ejaculatory duct
and prostate
2. Membranous urethra: short region that
passes through the pelvic floor

18. Urethra
• Passageway for urine and semen
• 3 regions
1. Prostatic urethra: passes through prostate
gland. Receives fluids from ejaculatory duct
and prostate
2. Membranous urethra: short region that
passes through the pelvic floor
3. Spongy (penile) urethra: extends the length of
penis and opens to outside

19. Penis
• Male copulatory organ. Transfers sperm to the
vagina

20. Penis
• Male copulatory organ. Transfers sperm to the
vagina
• Parts: Root, shaft, glans (head)

21. Penis
• Male copulatory organ. Transfers sperm to the
vagina
• Parts: Root, shaft, glans (head)
• Contains erectile tissue that can become
engorged with blood and become rigid

22. Accessory Glands: secrete fluids that
enter the urethra

23. Accessory Glands: secrete fluids that
enter the urethra
• Seminal vesicles: glands posterior to urinary
bladder. Produce viscous fluid that contains
fructose, which serves as an energy source for
sperm

24. Accessory Glands: secrete fluids that
enter the urethra
• Seminal vesicles: glands posterior to urinary
bladder. Produce viscous fluid that contains
fructose, which serves as an energy source for
sperm
• Prostate: Walnut sized. Encircles the urethra.
Produces thin, milky, alkaline fluid that
enhances the motility of sperm

25. Accessory Glands:
• Seminal vesicles: glands posterior to urinary
bladder. Produce viscous fluid that contains
fructose, which serves as an energy source for
sperm
• Prostate: Walnut sized. Encircles the urethra.
Produces thin, milky, alkaline fluid that
enhances the motility of sperm
• Bulbourethral gland: pea sized. Produces pre-
ejaculatory fluid, which provides lubrication
and works as a buffer to prevent chemical
reaction between acidic urine and basic
semen

26. Semen
• Slightly alkaline (pH = 7.5)

27. Semen
• Slightly alkaline (pH = 7.5)
• 60% of volume comes from seminal vesicles,
40% from prostate, <1% from sperm and
bulbourethral glands

28. Semen
• Slightly alkaline (pH = 7.5)
• 60% of volume comes from seminal vesicles,
40% from prostate, <1% from sperm and
bulbourethral glands
• Contains 50 – 150 million sperm per mililiter