Histology and embryology Male genital system Histology and embryology

Development Development of gonads Development of genital ducts Development of external genital

Origin Gonads – intermedial mesoderm of mesonephros Primordial germ cells – endoderm of yolk sac External genitalia – ectoderm and mesoderm

Indiferent stage Both sexes has same first stage coelomic epithelium primary germ cords primordial germ cells mesonephric duct (Wollfian) and tubules paramesonephric duct

Male gonads Y – chromosome if produced -> development of testis SRY -> TDF (testes determining factor) if produced -> development of testis usually from 7th week if not produced -> development of ovarium usually from 12th week „waiting period“

Development of testis TDF stimulates proliferation of primary germ cord -> medullary cords origin of seminiferous tubules and rete testis origin of Sertoli cells intermedial mesenchyme origin of Leydig cells rest of coelomic epithelium changed to tunica albuginea

Seminiferous tubules spermatogonia – from primordial germ cells Sertoli cells – surrounds spermatogonia secrete AMH – anti-müllerian hormone inhibition of paramesonephric duct (Müllerian) interstitial Leydig cells produce testosteron from 8th week no lumen till puberty

Descensus of the testis from thoracolumbal area to scrotum AMH, testicular growth, elongation of body gubernaculum – connective cord between testis and scrotum from 26th week mark of fetal maturity cryptorchism vs. ectopic testis

Genital ducts Connected medullar cords Mesonephric tubules rete testis Mesonephric tubules Efferent ducts Mesonephric duct (Wollfian) Epididymal duct, ductus deferens, vesicular glands, ductus ejaculatorius (ureter, pelvis, calices, collecting duct and tubules) Paramesonephric duct (Müllerian) disappear

External genitalia indiferent stage genital tubercle urogenital folds labioscrotal folds male genital penis spongious urethra scrotum

Testis Ducts Accesory glands Histology Testis Ducts Accesory glands

Testis Tunica albuginea Lobuli testis dense connective tissue - collagenous Lobuli testis Seminiferous tubules Interstitium

Seminiferous tubules Stages of spermatogonia surrounded by Sertoli cells hemato-testicular barrier – occluding junctions between medial part of Sertoli cells nutrition, support earlier stages are on the periphery of tubule production of AMH, inhibin regulated by follicle stimulating hormone

Spermatogenesis development of sperm from spermatogonia multiple division – two times meiotic spermiogenesis – maturation of spermatid into sperm

Sperm Head Middle piece Principal piece maturation is 64 days long (from first division of spermatogonia A) Head Acrosome (enzymes), nucleus Connecting piece - pair of centrioles Middle piece mitochondrial sheet, outer dense fibers (9), axonema Principal piece ribs of the fibrous sheet, outer dense fibers (7), axonema

Testicular interstitium Blood vessels Lymphatic vessel Leydig cells production of testosteron stimulation of spermatogenesis, maintanance of sex glands, sebaceous glands ... regulated by luteinizing hormon of hypophisis

Testis (M1)

Sperm maturity and transport pathway Tubuli recti et rete testis Epididymis Ductus deferens Ejaculatory duct

Tubuli recti et rete testis cuboideal Sertoliho cells no spermatogenic cells surrounded by lymphatic channels, blood vessels and Leydig cells

Epididymis Ductuli efferentes - in head columnar epitheluim with stereocilia and cilia non-motile sperm scalloped outline smooth muscle layer

Epididymis Ductus epididymidis - in body & tail function highly coiled one tubule - 4-6 m long pseudostratified columnar epi with stereocilia two layers of smooth muscle - thicker function maturation storage transport

Epididymis HE (M2)

Spermatic cord Vessels, muscles, lymphatic vessels, nerves Ductus defernes (Vas deferens) pseudostratified columnar epi lamina propria 3 layers of smooth muscle (L, C, L)

Spermatic cord HE (M3)

Ejaculatory duct + Ampulla pseudostratified columnar epi lamina propria muscular layer only in ampulla

Accesory Genital glands Seminal vesicles Prostate Bulbourethral glands

Seminal vesicles (Glandulae vesiculosae) cuboidela-to-pseudostratified epi folded mucosa smooth muscle layer (C+L) adventitia + serosa on apex ! function: 50-70% of seminal fluid fructose

Seminal vesicles HE (M4)

Prostate 30-50 tuboalveolar glands in fibromuscular stroma 3 regions of glands periurethral mucosal gl. periurethral submucosal gl. peripheral main gl.

Prostate simple-to-pseudostratified epi prostatic concrements (corpora amylacea) protein rich material, calcifications function: enrich the semen fluid, fibrinolysin, amylase, PSA

Prostate HE (M5)

Prostate WvG (M6)

Bulbourethral glands mucus secreting glands +galactose lubrication function

Penis three masses of erectil tissue 2x corpora cavernosa 1x corpus spongiosum communicating blood spaces (sinuses) surrounded by connective tissue artery -> sinus -> vein dilatation of artery (NO) compress vein, sinuses fill with blood -> erection occurs

Penis HE (M7)