Anatomy and Physiology of Farm Animals. Lecture Six. Anatomy and Physiology of Male Reproductive System II

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1 Anatomy and Physiology of Farm Animals Lecture Six Anatomy and Physiology of Male Reproductive System II 1

2 The male reproductive system Two testes Scrotum Spermatic cords Accessory glands Penis Prepuce The male duct system vasa efferentia vas deferens urethra external 2

3 The size of testes Bull length: cm width: cm weight: g Boar similar size as bull Ram, buck and stallion smaller size 3

4 Testes Tunica vaginalis 鞘膜 - cover testes - an extension of the peritoneum Tunica albuginea testis 白膜 - a thin white membrane of elastic connective tissue - numberous blood vessels are under surface Parenchyma - the functional layer of the testes 4

5 Testicles from the bull CM: Cremaster muscle DD: Ductus deferens EB: Epididymal body ET: Epididymal tail PTV: Parietal tunica vaginalis T: Testis Pathways to Pregnancy and Parturition, 1st ed.,1997 5

6 Testicles from the bull PTV: Parietal tunica vaginalis T: Testis TA: Tunica albuginea VTV: Visceral tunica vaginalis 6 Pathways to Pregnancy and Parturition, 1st ed.,1997

7 A bull testis. The outer layer of the testis is referred to as the tunica albuginea. A.Caput epididymis B.Corpus epididymis C.Cauda epididymis Applied Animal Reproduction, 6th ed.,

8 Parenchyma Divided into segments by incomplete septa of connective tissue 8

9 Testicles from the bull EH: Epididymal head ET: Epididymal tail M: Mediastinum PP: papiniform plexus TP: Testicular parenchyma Pathways to Pregnancy and Parturition, 1st ed.,1997 9

10 Sagittal section of testis illustrating segments of parenchymal tissue. Applied Animal Reproduction, 6th ed.,

11 Sagittal section of testis illustrating segments of parenchymal tissue. 11 Pathways to Pregnancy and Parturition, 1st ed.,1997

12 Seminiferous tubules - located within the segments m in diameter - the site of spermatozoa production Germ cells spermatogonia Nurse cells Sertoli cells - Larger and less numerous than germ cells - Their tight junction at the basement membrane forms the blood-testis barrier 12

13 (Sertoli cells) (Tangle of tails) (Spermatocyte) (Spermatid) (Spermatogonium) Scanning electron micrograph of a cross section of a seminiferous tubule. Applied Animal Reproduction, 6th ed.,

14 spermatogonia 精原細胞 (A1) 精原細胞 (A2) 精子生成 spermatogenesis 精母細胞生成 spermatocytogenesis 精原細胞 (A3) 精原細胞 (A4) 精原細胞 (I) 精原細胞 (B) 減數分裂 meiosis 初級精母細胞 spermatocyte 次級精母細胞精細胞生成精細胞變形 spermiogenesis 圓形精細胞 spermatids 成熟精細胞 spermatozoa 14

15 細胞核高爾基氏體粒線體 a. 頂體泡頂體顆粒 b. 頸部近端中心粒遠端中心粒鞭毛軸絲 c. 核後帽中片 d. 15

16 Head Tail Post nuclear cap Mid-piece endpiece Main-piece Acrosome Nucleus Implantation region, containing proximal centriole Structural diagram of spermatozoa 16

17 A portion of a seminiferous tubule showing the relationship of the germ cells to the adjacent Sertoli cells. Spermatids Primary spermatocyte Sertoli cell Spermatogonium Leydig cell 17 Pathways to Pregnancy and Parturition, 1st ed.,1997

18 Sertoli cells FSH * Androgen-binding protein * Inhibin Leydig cells LH * Testosterone * Other androgens 18

19 Testosterone Development of secondary sex characteristics Normal mating behavior The Function of the accessory glands Production of spermatozoa Maintenance of the male duct system 19

20 The male reproductive system Two testes Scrotum Spermatic cords Accessory glands Penis Prepuce The male duct system vasa efferentia vas deferens urethra external 20

21 The pendulous scrotum of the ram which houses the testes. Applied Animal Reproduction, 6th ed.,

22 The composition of scrotum The outer layer: thick skin - Connective tissue - Numerous large sweat and sebaceous glands The middle layer: tunica dartos - Smooth muscle interspersed fibers with connective tissue 22

23 Schematic illustration of a cross section of the spermatic cord. 23 Pathways to Pregnancy and Parturition, 1st ed.,1997

24 The composition of spermatic cord Muscle fibers Connective tissue A portion of the vas deferens 24

25 The functions of the spermatic cords * Provide vascular, lymphatic and neural connection to the body * Provide a heat exchanger (pampiniform plexus) * House the cremaster muscle 25

26 The functions of the scrotum and spermatic cords * Provide the physical support of the testes * Regulate the temperature of the testes 26

27 Temperature control of testes Drawing the testes - The tunica dartos (the smooth muscle lining the scrotum) Testosterone - The external cremaster (a striated muscle around the spermatic cord) Cooling mechanisms - Evaporation: sweat and sebaceous glands on the skin of the scrotum - Heat exchange: pampiniform venous plexus 27

28 Proposed pathway for scrotal sweating and thermal polypnea in the ram. Pathways to Pregnancy and Parturition, 1st ed.,

29 Cooling of the testis by heat exchange through the circulatory system. Applied Animal Reproduction, 6th ed.,

30 The pampiniform plexus as a countercurrent heat exchanger and testosterone exchanger. Pathways to Pregnancy and Parturition, 1st ed.,

31 The male reproductive system Two testes Scrotum Spermatic cords Accessory glands Penis Prepuce The male duct system vasa efferentia vas deferens urethra external 31

32 The accessory glands The vesicular glands The prostate gland The bulbourethral glands * The fluid volume of semen * Solution of buffers * Nutrients * Substances needed to assure optimal motility and fertility of semen 32

33 Table Sources and relative contribution (volume % ) to semen sources Epididymides and vasdeferentia Vesicular glands Prostate gland Bulbourethral glands Bull Boar

34 Table Average chemical composition of semen from different species (mg/100ml) Constitutent Bull Ram Boar Stallion Fructose Sorbitol Glycerylphos phorylcholine Inositol Citric acid Ergothionine Plasmalogen Sodium Potassium Chlorine Calcium Magnesium

35 Accessory glands of the bull, boar, ram and stallion showing their relationship to the ampula and urethra. 35 Applied Animal Reproduction, 6th ed., 2004

36 The male reproductive system Two testes Scrotum Spermatic cords Accessory glands Penis Prepuce The male duct system vasa efferentia vas deferens urethra external 36

37 Comparative diagram showing the shape of the glans penis of the bull, boar, ram and stallion. 37 Applied Animal Reproduction, 6th ed., 2004

38 Glans penis Free end of penis Distal end of bull penis Pathways to Pregnancy and Parturition, 1st ed.,

39 Glans penis Free end of penis Urethral process Preputial fold Distal end of ram penis Pathways to Pregnancy and Parturition, 1st ed.,

40 Cross section of bull penis CC: Corpus cavernosum CS: Corpus spongiosum DEC: Dorsal erection canals TA: Tunica albuginea U: Urethra Pathways to Pregnancy and Parturition, 1st ed.,

41 Characteristics of semen from farm animals Cattle Dairy Beef Sheep Swine Horse Volume (ml) * 60* Sperm conc. (billion/ml) Total sperm (billion) Motile sperm (%) Morphologically normal sperm (%) ph * Gel free portion 41

42 The male reproductive system Two testes Scrotum Spermatic cords Accessory glands Penis Prepuce The male duct system vasa efferentia vas deferens urethra external 42

43 The male reproductive system Two testes Scrotum Spermatic cords Accessory glands Penis Prepuce The male duct system vasa efferentia vas deferens urethra external 43

44 The structure of epididymus and external ducts outer layer : tunica serosa middle layer: smooth muscle innermost layer: epithelial layer 44

45 The function of epididymus Transportation Concentration Storage Maturation 45

46 The male reproductive tract Applied Animal Reproduction, 6th ed.,

ESUR SCROTAL AND PENILE IMAGING WORKING GROUP MULTIMODALITY IMAGING APPROACH TO SCROTAL AND PENILE PATHOLOGIES 2ND ESUR TEACHING COURSE

ESUR SCROTAL AND PENILE IMAGING WORKING GROUP MULTIMODALITY IMAGING APPROACH TO SCROTAL AND PENILE PATHOLOGIES 2ND ESUR TEACHING COURSE NORMAL ANATOMY OF THE SCROTUM MICHAEL NOMIKOS M.D. F.E.B.U. UROLOGICAL