1. Male Reproductive System
Nestor T. Hilvano, M.D., M.P.H.

2. Learning Objectives
Describe the components of the male reproductive system and state their functions.
Describe the anatomy of the testes, scrotum, and penis.
Explain the roles played by the male reproductive tract and accessory glands in maturation, nourishment, storage and transport of spermatozoa.
Outline the process of spermatogenesis and describe the role of sertoli cells.
Describe a sperm cell and trace the pathway taken by a sperm cell from its formation to its ejaculation.
State the normal composition of semen.
Discuss the hormonal control that regulate male reproductive functions.
Discuss BPH and prostatic cancer.

3. Components and Functions of Male Reproductive System
_______ – produce gametes and hormones
- testes
_______ - receive and transmit gametes
- epididymis, ejaculatory duct, urethra
_______ - secrete fluids
- seminal vesicles, prostate gland, bulbo-urehtral glands
_______ - perineal structures
- scrotum, penis
a. genital ducts b. accessory glands c. gonads d. external genitalia

4. Testes Male gonads, found in pouch called the scrotal sac.
Descent of testes (2 to 7 months)
- Gubernaculum testis (C.T.) shortens
- Essential for ________
What is cryptorchidism?

5. Spermatic Cord Extend bet. Abdominopelvic cavity and testes
Consist of layers of fascia and muscle
What structures are contained in spermatic cord?
Pass through inguinal canal, descend into scrotum
_______ - protrusion of visceral tissues into inguinal canal
a. femoral hernia b. hiatal hernia c. inguinale hernia d. all

6. Testes Tunica vaginalis Tunica albuginea
Septa divide testes into compartments containing seminiferous tubules
Sperm cells
Sustentacular (nurse/sertoli) cells
Interstitial (Leydig) cells produce _____.
Estrogen b. Testosterone
c. FSH d. LH

7. Spermatogenesis
Spermatogenesis- differentiation from spermatogonium to spermatozoas (sperm cells)
Stages of spermatogenesis:
Mitosis = Spermatogonia - type A produce more daughter cells (type A); some forms type B
Growth = type B differentiate into primary spermatocytes
Meiosis
- MI  primary spermatocytes to secondary spermatocytes
- MII  secondary spermatocytes to spermatids
4. Spermiogenesis= transformation of spermatids to
spermatozoas (sperm cells)

8. Spermatic Ducts Efferent ductules Epididymis (head, body and tail)
collecting sperm from semineferous tubules
Epididymis (head, body and tail)
coiled duct adhering to posterior of testis
Function _____________
Ductus deferens
muscular tube 45 cm long
Ejaculatory duct
formed from union of _____________ and duct of _____________.

9. Male Urethra ___Prostatic ___Membranous ___Penile
Middle and shortest segment
Traverses the corpus spongiosum; longest segment
First segment

10. Accessory Glands Seminal vesicles posterior to bladder
Secretion ___________
Prostate gland
below bladder, surrounds urethra and ejaculatory duct
Bulbourethral glands
near bulb of penis; lubricating fluid
Mucus and alkaline b. acid phosphatase
c. Fructose d. lactose

11. Penis Root, shaft, and glans skin over shaft loosely attached
prepuce (foreskin)
3 cylindrical bodies of erectile tissue
corpus spongiosum
encloses ____________
corpora cavernosa

12. Hormonal Control Hypothalamus produces GnRH
Stimulates anterior pituitary to secrete LH
stimulates interstitial cells to produce testosterone
FSH
stimulates sustentacular cells to secrete androgen-binding protein that interacts with testosterone to stimulate spermatogenesis

13. Effects of Testosterone
Enlargement of secondary sexual organs
During adulthood, testosterone sustains libido, spermatogenesis and reproductive tract

14. Semen or Seminal Fluid 2-5 mL of fluid Other components of semen
60% seminal vesicle fluid, 30% prostatic
normal sperm count million/mL
Other components of semen
fructose - energy for sperm motility
fibrinolysin liquefies semen within 30 minutes
prostaglandins stimulate female peristaltic contractions
spermine is a base stabilizing sperm pH at 7.2 to 7.6

15. Excitement and Ejaculation
Erection of penis
- parasympathetic triggering of nitric oxide
secretion
Ejaculation
- sympathetic nervous system propels
sperm through ducts
Resolution
- sympathetic signals constrict internal
pudendal artery and reduce blood flow to
penis

16. Homework (Self-Review)
Define terms: spermatogenesis, dartos muscle, cremasteric muscle, vasectomy, spermiogenesis, ejaculatory duct, inguinale hernia, & cryptorchidism.
Trace the pathway of sperm from its formation to ejaculation.
Give function(s) of the following: sertoli cell, testosterone, testes, epididymis, seminal vesicle, prostate gland, cowper’s gland, vas deferens, & male urethra.
Describe the spermatic cord.