1. Male Reproductive System

2. 1. Components: ---testis: produce the male germ cells- gametes(sperm) produce androgen-testosterone ---gernital ducts: store and conduct the sperm epididymis ductus deferens ejaculatory duct ---accessory gland: their secretion join into semen seminal vesicle prostate bulbourethral gland penis

3. 2. Testis 1) General structure: ① Capsule: a. tunica vaginalis: visceral layer-serosa b. tunica albuginea: thick, DCT /mediastinum testis: albuginea became thicker at posterior aspect /septum: thin septa extend radiately from mediastinum testis to divided the parenchyma into lobule

4. ② Lobule a. seminiferous tubule: /highly coiled /30-70cm long, 150-250 mm in D /begin as free blind end →run to posterior →become into straight tubule(tubules rectus) →enter mediastinum testis→rete testis→efferent duct→connect with epididymal duct b. testicular interstitial tissue: LCT between seminiferous tubule

5. 2) Seminiferous tubule: 30-70cm long, 150- 250um in D ---specific stratified epithelium: spermatogenic epi.(seminiferous epi) spermatogenic cells Sertoli or supporting cell myoid cell: under basal lamina

6. ① Spermatogenic cell: ---5-8 layers ---4 types of cells

7. a. spermatogonium ---outerest layer, one layer ---structure: /round, ellipsoid cell /12um /round N, deep stained

8. ---classification: type A: -dark type A(Ad): ovoid, deep-stained N, stem cell -Pale type A(Ap): ovoid, pale-stained N, differentiate into type B type B: round N, chromatin granules are distributed under nucleus membrane, division and differentiate into primary spermatocyte

9. b. primary spermatocytes ---diploid(2n)cell →duplicate DNA → tetraploid cell(4n) →division ---structure: round cell, become largest, 18 um, left the basal layer N: large, round, on different stage of division(the prophase of meiotic division up to 22 days) ---through first meiosis divides into two secondary spermatocyte(2n, 23X or 23Y)

10. c. secondary spermatocyte: ---nearer the lumen ---structure: round cell, 12um N: round deep-stained hard to see- short lived(divide quickly) ---through secondary meiosis divides into two spermatid(1n, 23X or 23Y)

12. d. spermatid ---structure: smallest cell, 8um located at innerest layer ---through spermiogenesis: spermatid become into spermatozoa

13. e. spermatozoa: ---structure of spermatozoa: 60 um length head: -pear-shaped -flattened -nucleus -acrosome tail: flagallum (centriole) -neck -middle segment: mitochondria sheath -principal segment -end segment

14. ---the processes of spermiogenesis i. condensation and elongation of N ii. formation of the acrosome -cover the anterior and lateral portion of N -contain hydrolytic enzymes for fertilization iii. formation of flagellum: for motility iv. formation of mitochondria sheath v. discharge of useless organelle and cytoplasm

15. ② Sertoli cell ---structure: LM: /columnar or pyramidal cell /rest on basal lamina /extending into lumen /no clear boundary /elongated N: triangular, ovoid, paler-stained, with prominent nucleolus

16. EM: /SER(more), RER(some), Golgi /mito, lysosome /MT, MF, /glycogen, lipid droplet /tight junction: basal compartment and abluminal compartment

17. ---function: a. support, protect, nourish, regulate and release germinal cell b. secret androgen-binding protein; bind to androgen, maintain the level of androgen concentration of lumen c. phagocytose degenerated cell and spermiogenic residual bodies d. constitute the blood-testis barrier

18. a. blood-testis barrier /components: endothelium basal lamina of endothelium CT basal lamina of seminiferous tubule tight junction of sertoli cell /function: protect the seminiferous cells from auto- immune reaction resistant to most harmful factors( radiation, body temperature, infection)

19. 3) interstitial tissue: ---LCT ---Leydig cell: structure: LM: -in groups -large, polygonal-shaped cell, with round N -acidophilic cytoplasm EM: steroid-hormone secreting cell ’ feature function: secrete testosterone- androgen

20. 4) tubule rectus and rete testis ---tubule rectus: simple cuboidal or low columnar epi. ---rete testis: simple cuboidal epi.