Male reproductive system

1. Male reproductive system LECTURE FOR MEDICAL STUDENTS DEPARTMENT OF HISTOLOGY, CYTOLOGY AND EMBRYOLOGY KhNMU 2012

2. The internal male genitalia: • the testes • the epididymis, • the vas deferens • the accessory sex glands - the seminal vesicles, the prostrate and the bulbourethral glands

3. Functions: • Reproductive --- produce the male gametes or spermatozoa, and • Endocrine --- produce male sexual hormone(testosterone)

4. Testes

5. The structure ofTestes Connective tissue • athickcapsule - thetunicaalbuginea • themediastinumtestis, projectsintothetestis and give septae • Septae – divide testes on 200-250 lobules

6. Each Lobule consist of: • Connective tissue -- Interstitium -- with Leidig cell • Seminiferous tubules (1-4 per lobule)

7. Leydig cells (15-20 µm) • synthesise and secrete testosterone.

9. The Convoluted Seminiferous Tubules Consists of two types of cells: • spermatogenic cells • Sertoli cells.

10. Spermatogenic cells • Spermatogonia- Type A spermatogonia - Type B spermatogonia • Primary spermatocytes • Secondary spermatocytes • Spermatids • Spermatozoa

11. Spermatogenesis • Type A spermatogonia are stem cells • which divide to form new generations of spermatogonia.

12. Spermatogenesis • Type B spermatogonia --- their final mitosis always results in the formation of Primary spermatocytes

13. Primary spermatocytes appear larger than spermatogonia. • They immediately enter the prophase of the first meiotic division, which is extremely prolonged (about 22 days!).

14. The completion of the first meiotic division results in the formation of Secondary spermatocytes

15. Secondary spermatocytes, are smaller than primary spermatocytes. • They rapidly enter and complete the second meiotic division.

16. Their division results in the formation of Spermatids, which lie in the luminal part of the seminiferous epithelium.

17. The terminal phase of spermatogenesis is called spermiogenesis • and consists of the differentiation of the newly formed spermatids into Spermatozoa

19. Spermatogenesis Cell divisions are incomplete. The cells remain connected by bridges of cytoplasm.

20. Structure of spermatozoa

21. Sertolicells • - provide mechanical support for the spermatogenic cells. • -- provide blood-testis barrier. • --- have a nutritive function.

23. Eccurrent ducts • MRS consists of DUCTS

24. epididymis - anatomy • The head of the epididymis receives the efferent ductules.   • The tail of the epididymis leads into the vas deferens.  

25. efferentductules

26. Epididymis ductus epididymidis It is lined by a very tall pseudostratified columnar epithelium: • principal cells, (have long stereocilia) • basal cells

27. ductusepididymis • The epididymal duct is extremely long (4 to 5 meters) but is highly convoluted • It is surrounded by smooth muscle and embedded within a loose, vascular stroma.

28. Male Accessory Reproductive Glands Seminal Vesicles

29. Seminal Vesicles functions: • the formation of the sperm coagulum, • the regulation of sperm motility and

30. Male Accessory Reproductive Glands

31. Prostate • is the largest accessory sex gland in men (about 2 x 3 x 4 cm). • The secretion contains citric acid, the enzyme fibrinolysin , acid phosphatase, a number of other enzymes and lipids.

32. Male Accessory Reproductive Glands • It contains 30 - 50 tubuloalveolar glands, which empty into 15 - 25 independent excretory ducts. These ducts open into the urethra.

33. the peripheral zone contains large, so-called main glands, whose ducts run posteriorly to open into the urethra. • the internal zone consists of the so-called submucosal glands, whereas • the innermost zone contains mucosal glands.

34. Male Accessory Reproductive Glands • The glands are embedded into a fibromuscular stroma, which consists of smooth muscle and connective tissue rich in collagenous and elastic fibres.

35. Male Accessory Reproductive Glands Prostate • The epithelium is cuboidal or columnar.