1. Biology 322 Human Anatomy I
Male Reproductive System

2. Human Reproductive System:
- Begins developing in 4th week of embryonic development.
- Remains “sexually indifferent” until 7th week in male
8th week in female

3. Male Female
7th & 8th Testes, penis, Clitoris, labia begin
weeks scrotum begin development
development
Both sexes: Gonads (ovaries & testes) remain inactive until puberty, when anterior pituitary stimulates maturation

4. Reproductive System of Adult Male - Midsagittal

5. Reproductive System of Adult Male – Coronal from back

6. Spermatic Cord Vas Deferens Testicular Nerve, Artery & Vein Plexus
containing
Vas Deferens
Testicular
Nerve,
Artery &
Vein Plexus
Cremaster
Muscle
(part of external
oblique muscle)
Epididymis
Scrotum
Testis

7. Testis or Testicle ~ 4 cm x 2 cm x 2 cm
Surrounded by dense irregular connective tissue: Tunica Albuginea
outside of which is
pouch of peritoneum
“dragged” into scrotum:
Tunica Vaginalis

8. Testis or Testicle Each testis divided into approximately 250
Lobules separated by connective tissue septa
Each lobule contains
one to four coiled
Seminiferous Tubules
where
Sperm are produced

9. Testis or Testicle
One Seminiferous Tubule

10. Seminiferous Tubule

11. Testis or Testicle Sustentacular Cells Spermatogonia
Primary Spermatocytes
Secondary Spermatocytes
Spermatids
Sperm

13. Testis or Testicle
Cells between
seminiferous =
tubules
groups of Interstitial
cells
which
secrete testosterone

14. Testis or Testicle
Sperm pass from seminiferous tubule into
tubulus rectus

15. Testis or Testicle
Sperm pass from seminiferous tubule into
tubulus rectus
then into rete testis

16. Sperm pass from seminiferous tubule into
tubulus rectus
then into rete testis
through efferent ductules

17. Sperm pass from seminiferous tubule into
tubulus rectus
then into rete testis
through efferent ductules
to epididymis

18. Epididymis
Long, coiled tube
In scrotum
Posterior to testis
Sperm take weeks to pass through epididymis where they mature:
become fertile
become motile
Debris also removed in epididymis

19. Sperm from epididymis pass into vas deferens or ductus deferens
which enters spermatic cord

20. Spermatic cord:
Passes through inguinal canal into abdomen

21. Within abdomen, vas deferens passes to posterolateral side of bladder
View

22. Within abdomen, vas deferens passes to posterolateral side of bladder where it ends as an enlarged ampulla
Posterior
View

23. Within abdomen are two accessory glands:
the seminal vesicles and the prostate
Posterior
View

24. Seminal Vesicles
Paired, posterior to bladder

25. Seminal Vesicles
Paired, posterior to bladder
Join with ampulla of vas deferens to form ejaculatory duct

26. Seminal Vesicles
Paired, posterior to bladder
Join with ampulla of vas deferens to form ejaculatory duct
Produces ~60% of fluid in semen
Contains nutrients for sperm
chemicals to decrease viscosity of cervical mucous
& stimulate peristalsis of uterus

27. Prostate
Inferior to bladder
Surrounds ejaculatory ducts and proximal part of urethra

28. Prostate
Inferior to bladder
Surrounds ejaculatory ducts and proximal part of urethra
Produces ~30% of fluid in semen
Contains chemicals to enhance sperm motility
& clot & then liquify semen
& neutralize acidity of vagina

29. Semen = mixture of sperm from vas deferens
seminal vesicle fluid
prostate fluid
enters urethra which passes through the penis

30. Penis
Three erectile bodies
Two corpora cavernosa
One corpus spongiosum
surrounding urethra

31. Penis:
Shaft
Bulb
or Root
Glans
Prepuce (foreskin)

32. Erection:

33. External
Urethral
Orifice
(through Corpus Spongiousum)
Urethra
(through Prostate)
Only at ejaculation
Ejaculatory Duct
Seminal Vesicles
Ductus Deferens
Constant
Epididymis
Efferent
Ductules
Rete
Testis
Tubulus
Rectus
Seminiferous
tubules

34. Semen:
Mixture of spermatozoa
seminal vesicle fluid
prostatic fluid
Normal ejaculate:
4 – 6 ml
50 – 100 million sperm per ml
Greatest in adolescence & young adults
Decrease with age

35. Your assignment for tonight:
Identify scrotum & testicles
Identify location of epididymis, vas deferens,
inguinal canal, prostate,
seminal vesicles, urethra
Identify corpora cavernosum & corpus spongeosum in
both bulb and shaft of erect penis
Observe clotting & liquification of freshly ejaculated semen