1. MALE REPRODUCTIVE SYSTEM
testis-03

2. MALE REPRODUCTIVE SYSTEM
 TESTES
 EPIDIDYMIS
 VAS DEFERENS
 SEMINAL VESICLES
 PROSTATE
testes within scrotum; temperature 2-3 degrees C below body temperature which is essential for sperm production
descent of testes during development (tunica vaginalis)
 BULBOURETHRAL GLANDS
 URETHRA

3. TESTIS H&E
SEMINIFEROUS TUBULES
testis-01

4. INTERSTITIAL CONN. TISSUE
TESTIS H&E
SEMINIFEROUS TUBULES
SEMINIFEROUS TUBULES
INTERSTITIAL CONN. TISSUE
testis-02

5. INTERSTITIAL CONN. TISSUE
TESTIS H&E
SEMINIFEROUS TUBULES
SEMINIFEROUS TUBULES
testis-03
INTERSTITIAL CONN. TISSUE

6. MALE REPRODUCTIVE SYSTEM
 SPERMATOGENESIS
SPERMATOGONIA
1º SPERMATOCYTE
2º SPERMATOCYTE
SPERMATIDS
SPERMATIDS
2º SPERMATOCYTE
tight junctions of lateral processes may temporarily open to permit the passage of spermatogenic cells toward the lumen
1º SPERMATOCYTE
SERTOLI CELLS:
- columnar with adjoining lateral processes
- extend from basal lamina to lumen
- Sertoli-Sertoli junctions divide seminiferous tubules into basal and adluminal compartments
SERTOLI CELLS
SPERMATOGONIA

7. MALE REPRODUCTIVE SYSTEM
SEMINIFEROUS TUBULES
 SPERMATOGENESIS
THREE PHASES:
(1) Spermatogonial Phase (Mitosis)
- spermatogonia proliferate by mitotic divisions to provide stem cells and cells which will proceed through spermatogenesis (1º spermatocytes)
(2) Spermatocyte Phase (Meiosis)
- diploid cells (2n) created in spermatogonial phase give rise to haploid cells (1n)
- Meiosis I (reduction division) & Meiosis II (equatorial division)
- 1º spermatocytes enter Meiosis I to form 2º spermatocytes which then enter Meiosis II and result in spermatids 5
exchange of genetic material in MI via crossing over
(3) Spermatid Phase (Spermiogenesis)
- spermatid differentiation into spermatazoa

8. MALE REPRODUCTIVE SYSTEM
 HORMONAL REGULATION OF MALE REPRODUCTIVE FUNCTION
HYPOTHALAMUS REGULATES ACTIVITY OF ANTERIOR PITUITARY (ADENOHYPOPHYSIS)
ADENOHYPOPHYSIS SYNTHESIZES HORMONES (LH and FSH) THAT MODULATE ACTIVITY OF SERTOLI AND LEYDIG CELLS
Luteinizing Hormone (LH): stimulates testosterone production by Leydig cells
Follicle Stimulating Hormone (FSH): stimulates production of sperm in conjunction with testosterone by regulating activity of Sertoli cells
SERTOLI CELLS STIMULATED BY FSH AND TESTOSTERONE RELEASE ANDROGEN BINDING PROTEIN WHICH BINDS TESTOSTERONE; THEREBY INCREASING TESTOSTERONE CONCENTRATION WITHIN THE SEMINIFEROUS TUBULES AND STIMULATING SPERMATOGENESIS

9. EFFERENT DUCTULES
EPIDIDYMIS
epididymus-07

10. epididymus-08
EPIDIDYMIS

11. Functions of Leydig Cells
Production of High Levels of Testosterone ( 5mg/day in adults )
Direct Production of Estradiol
Production of Dihydrotestosterone (DHT)
Production of dehydroepiandrosterone (DHEA) and androstenedione
Production of Progesterone and 17a -prog.
LKS

12. Functions of Sertoli Cells
Support Production of Spermatozoa
Production of Androgen-Binding Protein Intratesticularly (TeBG)
Form Blood-Testes Barrier
Produce Inhibin
Produce Seminiferous tubule fluid (bathing medium, nutrients, capacitation, motility)
LKS

13. End product: special structures

14. Spermatozoa Structure and Functions in Review
Head
Acrosome:
Nucleus:
Midpiece
Centrioles:
Mitochondria:
Tail: flagellum
Microtubules:
Figure 26-10: Sperm structure

16. Regulation of Spermatogenesis
GnRH  LH  Leydig cells  testosterone  sex charact.
GnRH  FSH  Sertoli cells  spermatoctye maturation
Inhibin feedback – FSH, testosterone – short & long loops