Male Reproductive System

1. Male Reproductive System • Components : • testis : product sperm • epididymis : sperm maturation • genital ducts : sperm transport • accessory reproductive glands : • seminal vesicles, prostate, bulbourethral glands • penis :

2. Testis • Sperm production : spermatogenesis • be maintained below normal body temperature (2-3oC) • Androgen production : testosterone • embryo : male fetus differentiation • puberty : • initiation of sperm production • accessory sex glands secretion • development of secondary sex characteristics • adult : sperm production maintenance

3. Testis Structures • Tunica albuginea : fibrous connective tissue • mediastinum : • septa : • Tunica vasculosa : loose connective tissue • Lobule : 250 • seminiferous tubules : 1-4 • interstitial (Leydig) cells : • Rete restis :

4. Seminiferous Tubules • Seminiferous epitheliul : stratified epithelium • spermatogenic cells : • spermatogonia : • spermatids : • Sertoli cells : supporting or sustentacular cells • Tunica propria : lamina propria • myoid cells (peritubular contractile cells) : • rhythmic contraction

5. Leydig Cells • Hormone secretion : androgen (testosterone) • activation for early differentiation of male fetus • inactivity after 5 months of fetus life • stimulation by gonadotropic at puberty • Structures : • elaborate smooth endoplasmic reticulum • motichormria with tubulovesicular cristae • acidophilic cells with crystals of Reinke

6. Spermatogenesis (I) • Spermatogonial phase : • type A dark (Ad) spermatogonia : • the stem cells of the seminiferous epithelium • type A pale (Ap) spermatogonia : • committed to differentiation • type B spermatogonia : • differentiated from type A spermatogonia • the last event in the spermatogonial phase

7. Spermatogenesis (II) • Spermatocyte phase : meiosis • primary spermatocyte : 4n • produced by type B spermatogonia • first meiotic division • homologous chromosomes crossing-over • give rise to secondary spermatocyte • secondary spermatocyte : 2n • second meiotic division • give rise to spermatid

8. Spermatid Phase (Spermiogenesis) • Golgi phase : • proacrosomal granules-acrosomal vesicle • axonemal complex : sperm tail • cap phase : acrosomal cap • acrosome phase : • manchette (flagellum develpoment), nucleus condense • maturation phase : • residual body is pinched off and phagocytized by Sertoli cells

9. Structure of Mature Sperm • Head : • acrosomal cap : • acrosin : acrosome reaction • nucleus : • Tail : • neck : centrioles • middle piece : mitochondria • principal piece : fibrous sheath and axonemal complex • end piece : only axonemal complex

10. Sperm Passway • Seminiferous tubules : • Straight tubules : • Rete testis (mediastinum) : • Efferent ductules : • Ductus epididymis : acquire motility • Female tract : acquire fertilization ability • capacitation : removal and replacement glycocalyx components on the sperm membrane

11. Seminferous Tubule • Cycle of the seminiferous epithelium : • synchronous mitotic meiotic divisions • 6 stages in man • 4.6 cycle from sperm release (16 days per cycle) • Waves of the seminiferous epithelium : • in rodents and other mammals • no waves in human seminferous tubule

12. Sertoli Cells • Serve as supporting cells : columnar epithelium • Sertoli-Sertoli junctional complex : • blood-testis barrier : physiologic compartmentalization • Sertoli-spermatid junctional complex : • no tight junction • Exocrine function : androgen-binding protein (ABP) • Endocrine function : inhibin

13. Intratesticular Ducts • Tubuli recti (straight tubules) : • proximal portion : lined by Sertoli cell • distal portion : simple cuboidal epithelium • Rete testis : • simple cuboidal to low columnar epithelium • single apical cilium • few apical microvilli

14. Efferent Ductules • Coni vasculosi • Pseudostratified columnar epithelium : • sawtooth appearance • Functions : • fluid reabsorption : • sperm transport : • ciliary action : • fibromuscular (muscular coat) contraction :

15. Ductus Epididymis • Sperm capacitation : glycocalyx modify • Pseudostratified columnar epithelium : • principal cells : stereocilia • basal cells : • halo cell : lymphocyte • Functions : • absorption and secretion • phagocytosis

16. Ductus Deferens • Pseudostratified columnar epithelium : • long microvilli • deep longitudinal folds • Ampulla : • branched mucosal folds • secretory function • Ejaculatory duct : no muscularis layer

17. Seminal vesicles • Mucosa : • primary, secondary, tertiary folds • pseudostratified columnar epithelium • secretion : under the control of testosterone • fructose, simple sugars, amino acids, ascorbic acid, prostaglandin • Smooth muscle coat : • Fibrous coat :

18. Prostate Gland and Bulbourethral Gland • Prostate Gland : • mucosal layer : • dependent on testosterone • cuboidal, squamous, columnar, pseudostratified • secretes protein enzymes : acid phosphatase, fibrinolysin, citric acid • prostatic concretion (corpora amylacea) : • submucosal layer : • peripheral layer : • Bulbourethral gland : Cowper’s gland • compound tubuloalveolar gland : mucus secretory gland

19. Semen • Fluid : • product from : • epididymis, vas deferens, prostate, seminal vesicles, bulbourethral gland • functions : • neutralize acid environment of urethra and vigina • prostaglandin : • Sperm : 3ml per ejaculate • 100 million per ml • 20% abnormal • 25% immotile

20. Penis • Erectile tissue : • corpora cavernosa : • corpus spongiosum : • Helicine arteries : • Tunica albuginea : fibroelastic layer • Glans : no adipose tissue • Prepuce : skin fold • Innervation : spinal, sympathetic and parasympathetic nerves