1. MALE REPRODUCTIVE SYSTEM dr sikander khan

3. Reproduction is the production of offsprings.
‘Re’ is Latin word. It means ‘again’.
Reproductive system is the system responsible for the formation of progeny .

4. In male, reproductive system includes:
Two testes, right and left.
Two epididymis, right and left.
Two deferent ducts, right and left.
Two ejaculatory ducts, right and left.
Two seminal vesicles, right and left.
One prostate gland.
One penis.
Two bulbo-urethral glands, right and left.

6. Testes are the primary sex organs. Here the male gametes are formed.
Epididymis, deferent ducts and ejaculatory ducts transport mature male gametes (sperms) to the organ of copulation.
Penis is the organ of copulation.
Seminal vesicles, prostate gland and bulbo-urethral glands are associated accessory glandular structures.

8. Testes These are primary reproductive organs.
They are homologous to ovaries in female.
They are ellipsoidal shaped structures.
They are not in pelvis, different to ovaries.
They are included in external genitalia and suspended in the scrotum.
Left testis is usually about 1 cm lower than the right.

9. Each testis is compressed laterally, having upper and lower poles, medial and lateral surfaces and anterior and posterior borders. The anterior border is convex and posterior border is nearly straight.
Average testicular dimensions are 4-5 cm in length, 2.5 cm breadth and 3 cm antero-posterior diameter.
Their weight varies from g.

12. COVERINGS OF TESTIS
Tunica Vaginalis is like peritoneum. It covers the whole testis except posterior border.
Tunica albuginea is a dense irregular connective tissue. It forms the true capsule of testis.
Tunica Vasculosa is present internal to tunica albuginea.

13. Microscopic picture of testis showing three coats of testis.

14. MICROSCOPIC STRUCTURE
There are lobules in each testis.
Each lobule contains 1-3 horseshoe shaped highly convoluted seminiferous tubules embedded in loose connective tissue.
This loose connective tissue contains groups of interstitial cells of Leydig outside the seminiferous tubules.

15. SEMINIFEROUS TUBULES
Highly convoluted tubules. About 0.2mm in diameter and 50cm in length. Horseshoe shaped. The ends are straight. Here they are given the name straight tubules. The straight tubules open into the rete testis.
Each seminiferous tubule is lined by complex stratified epithelium called seminiferous epithelium. The epithelium rests on a thin basal lamina, which is covered by connective tissue containing fibroblasts, numerous fibers and myoid cells.

17. Sustentacular Cells of Sertoli.
Spermatogenic Cells

19. Sustentacular Cells of Sertoli
These are tall columnar cells resting on basal lamina of seminiferous tubules. The cell outline is very irregular and indistinct. They have invaginations on their basal surfaces, their sidewalls and their luminal surfaces.
The nucleus is towards the base. It is located some distance above the base of the cell. It is pale and ovoid. It contains a nucleolus.

21. The adjacent surfaces show complex occluding junctions.
These junctions are near the bases and constitute blood-testis barrier.

23. Spermatogenic Cells These are germ cells.
They form a stratified layer of epithelium consisting of four to eight cell types.

24. Spermatogonia:
Until puberty these are the only germ cell type present. They occupy a space present between the basal lamina and sertoli cells. They contain 46 chromosomes.
Three basic types of spermatogonia are:
Type A dark spermatogonia
Type A pale spermatogonia
Type B spermatogonia
Spermatogonia multiply by mitosis.

25. Primary Spermatocytes:
Some of the spermatogonia cells enlarge and differentiate into primary spermatocytes. They are the largest germ cells seen within seminiferous tubules. Initially they are in the basal compartment of seminiferous tubule. Then they cross blood-testis barrier and lie between the adjacent Sertoli cells. Here they are in the invaginations present in the lateral walls of Sertoli cells
Each cell is spherical or ovoid in outline. They contain 46 chromosomes.

26. Secondary Spermatocytes:
Primary spermatocytes undergo first meiotic division and form secondary spermatocytes.
These are about half the size of primary spermatocytes.
They lie in the invaginations in the lateral walls of Sertoli cells near the lumen of the seminiferous tubules.
They contain 23 chromosomes.

27. Spermatids:
Secondary spermatocytes undergo second meiotic division and form spermatids. These are about the size of secondary spermatocytes and contain 23 chromosomes.
They migrate to the luminal surface of Sertoli cell and lie in the invaginations there.
Here they transform into spermatozoa by a process called spermiogenesis.

28. Spermatozoa:
Each spermatozoon is 60 µm in length
It consists of head, neck, middle piece and tail.
Head is 4 µm in length, 3 µm in width and 1 µm in thickness
It has
a nucleus
with a cap called acrosome
surrounded by cell membrane

29. Middle piece is separated from head by a narrow neck.
It is 7 µm in length and 1 µm in diameter
It contains
Axoneme
a core of longitudinal filaments
2+9 arrangement
surrounded by nine dense fibers
surrounded by a sheath of mitochondria
Surrounded by cell membrane

30. Tail has two parts Principle piece is 40 µm in length. It consists of
Axoneme. It has two central and nine peripheral double filaments
Seven outer dense fibers
Fibrous sheath
Cell membrane
End piece (8 µm in length) has axoneme and cell membrane only

31. Heads are embedded in the invaginations on luminal surfaces of Sertoli cells
and tails float in the lumen of seminiferous tubules.

34. Sperms:
When the spermatozoa become detached from Sertoli cell and free in the lumen of seminiferous tubules they are called sperms.

35. The interstitial tissue, within the lobules is loose connective tissue containing.
Cells. Fibroblasts, macrophages, mast cells, undifferentiated mesenchymal cells and interstitial cells of Leydig.
Collagen fibers.
Blood and lymph vessels.
Nerves.

36. The specific interstitial cells of Leydig are a marked feature of this tissue.
They lie in groups.
They are large rounded cells contain central rounded nucleus.
The nucleus contains course chromatin granules and a distinct nucleolus.
Under electron microscopy my dear students you will observe abundant smooth endoplasmic reticulum.
Interstitial cells of Leydig secrete testosterone.

37. Smooth endoplasmic reticulum is concerned with synthesis of steroid hormone.
Rough endoplasmic reticulum is concerned with synthesis of proteins.

38. Spermatogenic Cells Spermatogonia: 46 Mitosis
Primary Spermatocytes: Meiosis I
Secondary Spermatocytes: Meiosis II
Spermatids: Spermeogenesis
Spermatozoa: Attached
Sperms: Free

40. Sertoli or sustentacular cells
Spermatogenic cells
Begin sperm production at puberty
Sertoli or sustentacular cells
Junctions form blood-testis barrier
Nourish spermatogenic cells
Carry out phagocytosis
Control spermatogenic movement
Produce fluid for transport
Secrete hormone inhibin
Leydig (interstitial) cells
Secrete testosterone

41. Thanks