1. Male Reproductive System
Chapter 8
Male Reproductive System

2. Contents Introduction Histology and Spermatogenesis Androgen
Diseases and disorders

3. Section I
INTRODUCTION

4. Male and female reproductive systems
Function together to produce offspring
Female reproductive system nurtures developing offspring
Produce important hormones

5. Similarities and differences between males and females, but same goal: new life
Primary sex organs: gonads
Testes in males
Ovaries in females
produce the gametes (sex cells)
Sperm in males
Ovum (egg) in females
Endocrine function: secretion of hormones
Accessory sex organs
Internal glands and ducts
External genitalia

6. Male Reproductive System: Hormones
Hypothalamus
Gonadotropin-releasing hormone (GnRH)
Stimulates anterior pituitary to release FSH and LH
Pituitary
Follicle-stimulating hormone (FSH) – initiates spermatogenesis
Luteinizing hormone (LH) – stimulates interstitial cells in the testes to produce testosterone
Testis
Testosterone
Secondary sex characteristics
Maturation of male reproductive organs
Inhibin and avtivin

7. Case: Unexpected Fracture 1
John Smith, 25 year old man
Tripped while crossing the road and fallen awkwardly
Had severe chest pain over the site of the impact
History
lived with his wife and worked as a chef
Had bee attempting to have a baby for 2 years, with no success
Nothing else is special

8. Case: Unexpected Fracture 2
Physical Examination
Tall with long arms and legs
Swelling of breast tissue
Lower ribs was very tender and was bruising over the skin
Scanty body, pubic and axillary hair
Testes were very small

9. Case: Unexpected Fracture 3
Chest Radiography
Several fracture in the right lower ribs because of a trivial fall
The doctor concerned about
The finding on clinical examination
Severity of the fracture despite the relatively trivial fall.

10. Case: Unexpected Fracture 4
Blood Test LH
35 U/L (normal < 10 U/L)
FSH
65 U/L (normal < 10 U/L)
Testosterone
4 nmol/L (normal 9-41 nmol/L)
Sperm count
Very low

11. HISTOLOGY AND SPERMATOGENESIS
Section 2
HISTOLOGY AND SPERMATOGENESIS

12. Histology and Spermatogenesis
Histology of the testis
Spermatogenesis

13. Anatomy of the Testis 鞘膜 白膜

14. Seminiferous Tubules （细精管）

15. Transverse Section of Seminiferous Tubules
支持细胞

16. Spermatogenesis (精子发生）
65 – 70 days in human
Three stages
12-21 days for the transportation of sperms in ducts
epididymis - deferent duct - ejaculatory

17. 1st stage: formation of spermatocytes
Spermatogonia （精原细胞）are stem cells
Least differentiated
Lie in basal lamina （基底层）
Divide continuously by mitosis (result 2n or diploid): daughter cells A (remains a stem cell) or B (goes on)
When start to undergo meiosis are called spermatocytes （精母细胞）

18. Blood-testis Barrier

19. Blood-testis barrier
Sperm surrounded by Sertoli* (sustenacular) cells: tight junctions
Prevents escape of unique antigens seen as foreign
These would activate the immune system
Autoimmune response would cause sterility
Sertoli cell (sustentacular cell)
Tight junction

20. The barriers may be disrupted, result in the exposure of sperms to the immune system.
And thus the production of antibody

21. 2nd stage: meiosis I
Each primary spermatocytes (2n) undergoes meiosis I to become 2 secondary spermatocytes:
Each secondary spermatocyte undergoes meiosis II to become 2 spermatids
4 total spermatids from each spermatogonium

22. 3rd stage: spermiogenesis (精子形成）
Head contains
Nucleus with chromatid (genetic material)
Acrosome（顶体） with enzymes for penetrating egg
Midpiece: mitochondria spiraled around the core of the tail
Tail is an elaborate flagellum (allows sperm to swim)

23. Epididymis （附睾）
Efferent ductules (输出小管）
Duct of the epididymis (附睾管）

24. Ｅfferent Ｄuctules At the head of epididymus
Lined by simple columnar epithelium
Cilia and smooth muscle in wall help move sperm along
Empty sperm into duct of the epididymus

25. Duct of epididymis Pseudostratified （假复层） columnar epithelium
Highly coiled 6m long duct
Pseudostratified （假复层） columnar epithelium
Sperm mature (20 days)
Sperm gain ability to swim
Sperm stored in the tail of the epididymis in preparation for ejaculation.
Maximal: for several months
Pseudostratified columnar epithelium

26. Ducts Deferens （输精管） 45 cm Thick layers of smooth muscle
Stores and transports sperm during ejaculation
固有层

27. Prostate （前列腺） Size & shape of a chestnut （栗子）
Encircles 1st part of urethra （尿道）
3 types of glands
Secrete citric acid （柠檬酸） and acid phosphatase
Contribute to semen （精液）(milky fluid and enzymes)
PSA measured as indicator of prostate cancer (“prostate specific antigen”)
Fibromuscular stroma

28. Ejaculatory duct （射精管）
The Sperm Pathway
Sperm Pathway
Ducts Deferens （输精管）
Seminal vesicles （精囊）
Testes
Ejaculatory duct （射精管）
Sperm
Prostate gland
Epididymis （附睾）
Urethra
Expulsion
from the body

29. Sperm

30. Sperm A Health Man Produces
From puberty to old age
200 million every day
Several trillion over a lifetime

31. Seman Analysis （精液检查） Sperm "Count"
Sperm Morphology (Size, Shape, Appearance)
Sperm Motility
Chemical and Biochemical Semen Characteristics (pH, Color and Turbidity, Liquefaction, Viscosity.)
Sperm Penetration Assays
Post Coital Tests and Sperm-Cervical Mucus Interaction
Antisperm Antibodies (Sperm "Allergy")

32. Section 3
HORMONAL REGULATION

33. Hormones Secreted by the Hypothalamus and Their Effects on Anterior Pituitary

34. Endocrine Cells in Testes
Leydig Cell
Testosterone
Sertoli Cell
Inhibin （抑制素）
Activin （激活素）

35. Metabolism of Testosterone
芳香化酶

36. Physiology Effect of Testosterone

37. Hypothalamus-Pituitary-Testes Axis

38. The Relationship between GnRH and Testosterone in Lifetime in Male

39. Testosterone Production Throughout the Life in Male

40. DISEASES AND DISORDERS
Section 4
DISEASES AND DISORDERS

41. Content Hypogonadism Therapeutic and abuse uses of androgens
Primary
Secondary
Tertiary
Therapeutic and abuse uses of androgens
Declining sperm counts

42. Hypogonadism Primary Hypogonadism Secondary Hypogonadism
Caused by the disorder of testicular function itself
Secondary Hypogonadism
Caused by the pituitary gland
Tertiary Hypogonadism
Failure of GnRH secretion from hypothalamus
Kallmann’s syndrome （卡尔曼综合征）

43. Primary Hypogonadism Disease Treatment Klinefelter’s syndrome
Chromosomal abnormality that result in small testes and failure of secondary sex characteristics
Mumps orchites (腮腺炎性睾丸炎）
Cryptorchidism (隐睾症）
Testicular damage from radiation or chemotherapy
Treatment
Steroid replacement
To maintain secondary sex characteristics and sexual function
The infertility is not reversible

44. Case: Unexpected Fracture 1
John Smith, 25 year old man
Tripped while crossing the road and fallen awkwardly
Had severe chest pain over the site of the impact
History:
lived with his wife and worked as a chef
Had bee attempting to have a baby for 2 years, with no success
Nothing else is special

45. Case: Unexpected Fracture 2
Physiological Examination
Tall with long arms and legs
Swelling of breast tissue
Lower ribs was very tender （osteoporosis，骨质疏松症)
Scanty body, pubic and axillary hair
Testes were very small
Chest Radiography
Several fracture in the right lower ribs because of a trivial fall

46. Case: Unexpected Fracture 3
Blood Test
Lutinizeing hormone (LH)
35 U/L (normal < 10 U/L)
Follicle stimulating hormone (FSH)
65 U/L (normal < 10 U/L)
Testosterone
4nmol/L (normal 9-41 nmol/L)
Sperm count
Very low

47. Therapeutic and Abuse Uses of Androgens
Therapeutic use
Treat the symptoms of hypogonadism
Abuse
Teenagers: Improve the body image
body-builders: Improve body mass
Athlete
improve muscle mass
enhance aggression
improve endurance
faster recovery from injury

48. Side-effect of Abuse Uses of Androgens
Men: Infertility -
the testes will shrink and stop producing testosterone and sperm
Women
Virilization (女性男性化） , amenorrhoea （闭经）and liver cancer
海蒂•格里克
安得利斯
1997 -

49. Declining Sperm Counts
Feminization （雌性化） of male wildlife populations caused by
Chemicals in the environment that have oestrogenic effect, Including
pesticides
Various organochlorides
Excreted oestrogens in sewage effluent
For human?