1 / 33

HISTOLOGY & EMBRYOLOGY Teaching PPT Dept. of Anat., Hist. & Embry. School of Medicine Xi’an Jiaotong University

HISTOLOGY & EMBRYOLOGY Teaching PPT Dept. of Anat., Hist. & Embry. School of Medicine Xi’an Jiaotong University. Male Reproductive System. Qiu Shudong. Introduction. Testes Genital ducts: Epididymis, Ductus deferens, Ejaculatory ducts Urethra Accessory glands:

mulan
Download Presentation

HISTOLOGY & EMBRYOLOGY Teaching PPT Dept. of Anat., Hist. & Embry. School of Medicine Xi’an Jiaotong University

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. HISTOLOGY & EMBRYOLOGY Teaching PPT Dept. of Anat., Hist. & Embry. School of Medicine Xi’an Jiaotong University

  2. Male Reproductive System Qiu Shudong

  3. Introduction Testes Genital ducts: Epididymis, Ductus deferens, Ejaculatory ducts Urethra Accessory glands: Seminal vesicles, Prostate, Bulbourethral gland Penis

  4. TESTES I. General Structure : Tunica vaginalis (mesothelium) Testicular Tunica albuginea & capsule mediastinum testis Tunica vasculosa (l.c.t & Cap.) Septula testis Testicular Seminiferous tubule lobules Straight tubules,rete testis & efferent ductules Interstitial tissue & Leydig cell Function: Produce sperm & sexual hormone

  5. Seminiferous tubule Interstitial tissue Testicular Capsule Straight tubule Testicular lobules

  6. II. Seminiferous Tubules D = 150 - 250um, 30 - 70cm long, Spermatogenic Spermatogenic cells epithelium Sertoli cells Basement membrane Collagenous fibers Limiting membrane Myoid cells

  7. Seminiferous Tubules

  8. Spermatogenic epithelium Limiting m. Sertoli Cell Interstitial tissue & Leydig cell

  9. (l) Spermatogenic cell & Spermatogenesis • At puberty / FSH stimulating • Spermatogenic cells differentiate to spermatozoa • Successive spermatogenic cells : • spermatogonia • primary spermatocyte • secondary spermatocyte • spermatids • spermatozoa. • Spermatogenesis: The process from spermatogonia to spermatozoa. • Including 3 phases:

  10. A. Spermatocytogenesis: spermatogonia primary spermatocytes by mitosis B. Meiosis: Spermatocytes spermatids, through 2 succeesive meiosis w/ reduction by half number of chromosomes & half amount of DNA per cell C. Spermiogenesis: Spermatids spermatozoa by modifying structures & shape (no division).

  11. Spermatocytogenesis primary Meiosis secondary spermatids Spermiogenesis spermatozoa

  12. Spermatogenesis& Spermiogenisis Primary Spermatocyte 1st meiosis 2nd meiosis Secondary Spermatocyte Spermatid Spermatozoon

  13. (2) Spermatogonia & Spermatocytogenesis • Spermatogonium: The most immature spermatogenic cell, on B.M. Round & small (12 um), a round nucleus w/ l-2 nucleoli & finely-granulated chromatin. • Spermatocytogenesis: At sexual maturity, a series of successive mitosesto form: (l) spermatogonia A (stem cells); (2) spermatogonia B, ( primary spermatocyte).

  14. 46 chromasomes & 2n DNA 46 chromasomes & 2n DNA 46 chromasomes & 4n DNA

  15. (3) Primary & 2nd spermatocyte & meiosis: • Primary spermatocyte In middle zone of the epithelium. Easy to seen in section (the first meiosis need 22 days) The largest one (16-18um) , nucleus w/ prominent chromosomes, 46 (44 +XY) & 4N DNA. Primary spermatocyte →→→ Secondary spermatocyte(by 1st meiosis) • Secondary spermatocyte Near lumen. Difficult to observe in section (the second meiosis quickly completed). Round (12 um) & a pale-stained nucleus, 23 ( 22+X or 22+y) & 2N DNA. Secondary spermatocyte →→→ spermatids(by 2nd meiosis)

  16. 46 chromasomes& 2n DNA 46 chromasomes& 4n DNA 23 chromasomes& 2n DNA 23 chromasomes & 1n DNA

  17. (4) Spermatid & spermiogenesis • Spermatid Close to lumen. spherical (6 um). 23 (22+X or 22+Y) & 1N DNA (haploid) • Spermiogenesis A complex process that a round spermatid transforms into a tadpole-like spermatozoon (no further division occurs) . Including:

  18. (a) Golgi apparatus acrosomal granule acrosomal vesicle acrosomal cap acrosome (covers 2/3 of the nucleus anteriorly) (b) Condensation of chromatin a elongated & flattened nucleus. (c) A centriole a flagellum (axoneme) At the posterior pole of the nucleus ( for motility). (d) Mitochondria a sheath of mitochondria. Spiral around initial part of the tail (e) Parts of the cytoplasm cast off as a residual bodies (phagocytized by Sertoli cells). (a) Golgi apparatus acrosomal granule acrosomal vesicle acrosomal cap acrosome (covers 2/3 of the nucleus anteriorly) (b) Condensation of chromatin a elongated & flattened nucleus. (c) A centriole a flagellum (axoneme) At the posterior pole of the nucleus ( for motility). (d) Mitochondria a sheath of mitochondria. Spiral around initial part of the tail (e) unnecessary cytoplasm cast off as a residual bodies (phagocytized by Sertoli cells).

  19. (5) Human Spermatozoon: • 60 um long, consist of a head & a tail. • Head: pear-shaped & flattened w/ a nuclear & a acrosome (contains hydrolytic enzyme important for fertilization). • Tail: 55um in length w/ a microtubular axoneme in the core. Subdivided into 4 segments: (a)The neck, containing a centriole (connect) (b)The middle segment (5-7um), containing a sheath of mitochondria (provide energy). (c)The principal segment (45um), containing a fibrous sheath (support the tail). (d)The end piece (5-7um), containing a microtubular axoneme.

  20. Mis. Egg , I miss you very much! Mr. sperm, Mr. Sperm , I miss you very much too !

  21. The Passage of the Sperm Seminiferous tubules straight tubules rete testis efferent ductules genital ducts

  22. 2. Sertoli cells: Columnar cell rest on B.M., the free surface reaches to lumen. spermatogenic cells locate b/w adjacent cells Features & function: LM: no clear outline, basally-located, ovoid nucleus w/ a distinct nucleolus. EM: (l) abundant sER., Gl., Ly., Mf., & Mt. (2) Tight junctions present b/w adjacent Sertoli cells (isolate spermatogonia from other spermatogenic cells).

  23. S E R T O L I C E L L

  24. C. Function: (l) Support & nourish spermatogenic cells; (2) Secrete fluid to help the sperm moving; (3) Phagocytize & digest the residual bodies (4) Synthesize & secrete ABP (androgen binding protein) which combines androgen in seminiferous tubule to stimulate spermatogenesis; (5) Form the blood-testis barrier: Tight junctlon constitute the main part (rest: B.M. & limiting membrane). Fnction: separates germ cells from immune system & prevents auto-immune reaction. (6) Preventsome physical & chemical factors from damaging germ cells, e.g. radiation, body temperature, infection

  25. III. Interstitial tissue • B/w seminifeious tubules • L.c.t. w/ small b.v. & l. v., nerves & Leydig cells: a. in groups & near b.v.; b. large, round or polygonal, acidophilic, round nucleus w/ prominent nucleolus. c. EM: abundant sER, tubular cristae Mit., lipid droplets; *rod-shaped crystalloids.

  26. Function: secrete testosterone • for proliferation & differentiation of germ cells, • for development of genital system, • for maintenance of male secondary sex characteristics.

  27. IV. Regulation of testicular function: 1. Leydig cells are controlled by interstitial cell stimulating hormone (ICSH); 2. Follicle stimulating hormone (FSH) regulates the function of Sertoli cells 3. ICSH & FSH are secreted by cells in glandular pituitary.

  28. Epididymis I. A head, a body & a tail. II. Consist of a highly coiled ductus epididymis iii. The ductus is lined a pseudostratified columnar epithelium • The principal cells have numerous stereocilia • The base cells may be germinative

  29. IV. Function: • Absorb most of the fluid that leaves the testis • Secrete carnitine, glycerylphosphoryo-choline, sialic acid, etc. • Spermatozoa become mature functionally, acquiring motility & fertilizability when they slowly pass the ductus

  30. prostate • Consist of compound glands around the urethra, c.t. and smooth muscles • Glandular epithelium is columnar, cuboidal or pseudostratified. • Prostatic concretions may be found in the alveoli • Function: The secretion containing acid phosphatase makes up the main part of seminal plasma * Benign hypertrophy of prostate can lead to obstruction of the urethra. ** Prostate cancer developes in main glands

More Related