Male genital system

Male genital system Male genital system

Histology and embryologyHistology and embryology

DevelopmentDevelopment

Development of gonadsDevelopment of gonads Development of genital ductsDevelopment of genital ducts Development of external genitalDevelopment of external genital

OriginOrigin

Gonads – intermedial mesoderm of Gonads – intermedial mesoderm of mesonephrosmesonephros

Primordial germ cells – endoderm of Primordial germ cells – endoderm of yolk sacyolk sac

External genitalia – ectoderm and External genitalia – ectoderm and mesodermmesoderm

Indiferent stageIndiferent stage

Both sexes has same first stageBoth sexes has same first stage

• coelomic epitheliumcoelomic epithelium– primary germ cordsprimary germ cords

• primordial germ cellsprimordial germ cells• mesonephric duct (Wollfian) and mesonephric duct (Wollfian) and

tubulestubules• paramesonephric ductparamesonephric duct

Male gonads Male gonads

Y – chromosomeY – chromosome• SRY ->SRY -> TDF (testes determining factor) TDF (testes determining factor)

if produced -> development of testisif produced -> development of testis• usually from 7th weekusually from 7th week

if not produced -> development of if not produced -> development of ovariumovarium• usually from 12th weekusually from 12th week• „„waiting period“waiting period“

Development of testisDevelopment of testis

TDF stimulates proliferation of primary TDF stimulates proliferation of primary germ cord -> medullary cordsgerm cord -> medullary cords• origin of seminiferous tubules and rete origin of seminiferous tubules and rete

testistestis• origin of Sertoli cellsorigin of Sertoli cells

intermedial mesenchymeintermedial mesenchyme• origin of Leydig cellsorigin of Leydig cells

rest of coelomic epithelium changed to rest of coelomic epithelium changed to tunica albugineatunica albuginea

Seminiferous tubulesSeminiferous tubules

spermatogonia – from primordial germ spermatogonia – from primordial germ cellscells

Sertoli cells – surrounds spermatogoniaSertoli cells – surrounds spermatogonia• secrete AMH – anti-müllerian hormonesecrete AMH – anti-müllerian hormone

– inhibition of paramesonephric duct (Müllerian)inhibition of paramesonephric duct (Müllerian) interstitial Leydig cellsinterstitial Leydig cells

• produce testosteron from 8th weekproduce testosteron from 8th week

no lumen till pubertyno lumen till puberty

Descensus of the testisDescensus of the testis

from thoracolumbal area to scrotumfrom thoracolumbal area to scrotum• AMH, testicular growth, elongation of bodyAMH, testicular growth, elongation of body• gubernaculum – connective cord between gubernaculum – connective cord between

testis and scrotumtestis and scrotum from 26th weekfrom 26th week mark of fetal maturitymark of fetal maturity

cryptorchism vs. ectopic testiscryptorchism vs. ectopic testis

Genital ductsGenital ducts Connected medullar cordsConnected medullar cords

• rete testisrete testis Mesonephric tubulesMesonephric tubules

• Efferent ducts Efferent ducts Mesonephric duct (Wollfian)Mesonephric duct (Wollfian)

• Epididymal duct, ductus deferens, vesicular Epididymal duct, ductus deferens, vesicular glands, ductus ejaculatoriusglands, ductus ejaculatorius

• (ureter, pelvis, calices, collecting duct and (ureter, pelvis, calices, collecting duct and tubules)tubules)

Paramesonephric duct (Müllerian) Paramesonephric duct (Müllerian) disappeardisappear

External genitaliaExternal genitalia

indiferent stageindiferent stage

genital tuberclegenital tubercle urogenital foldsurogenital folds labioscrotal foldslabioscrotal folds

male genitalmale genital

penispenis spongious urethraspongious urethra scrotumscrotum

HistologyHistology

TestisTestis

DuctsDucts

Accesory glandsAccesory glands

PenisPenis

TestisTestis

Tunica albugineaTunica albuginea• dense connective tissue - collagenousdense connective tissue - collagenous

Lobuli testisLobuli testis• Seminiferous tubulesSeminiferous tubules• InterstitiumInterstitium

Seminiferous tubulesSeminiferous tubules

Stages of spermatogonia surrounded by Sertoli cellsStages of spermatogonia surrounded by Sertoli cells• hemato-testicular barrier – occluding junctions between hemato-testicular barrier – occluding junctions between

medial part of Sertoli cellsmedial part of Sertoli cells• nutrition, supportnutrition, support• earlier stages are on the periphery of tubuleearlier stages are on the periphery of tubule• production of AMH, inhibinproduction of AMH, inhibin• regulated by follicle stimulating hormoneregulated by follicle stimulating hormone

SpermatogenesisSpermatogenesis

development of sperm from development of sperm from spermatogoniaspermatogonia

multiple division – two times multiple division – two times meioticmeiotic

spermiogenesis – maturation of spermiogenesis – maturation of spermatid into spermspermatid into sperm

SpermSperm

• maturation is 64 days long (from first division of maturation is 64 days long (from first division of spermatogonia A)spermatogonia A)

HeadHead• Acrosome (enzymes), nucleusAcrosome (enzymes), nucleus• Connecting piece - pair of centriolesConnecting piece - pair of centrioles

Middle pieceMiddle piece• mitochondrial sheet, outer dense fibers (9), mitochondrial sheet, outer dense fibers (9),

axonemaaxonema Principal piecePrincipal piece

• ribs of the fibrous sheet, outer dense fibers (7), ribs of the fibrous sheet, outer dense fibers (7), axonemaaxonema

Testicular interstitiumTesticular interstitium

Blood vesselsBlood vessels Lymphatic vesselLymphatic vessel Leydig cellsLeydig cells

• production of testosteronproduction of testosteron– stimulation of spermatogenesis, stimulation of spermatogenesis,

maintanance of sex glands, sebaceous maintanance of sex glands, sebaceous glands ...glands ...

– regulated by luteinizing hormon of regulated by luteinizing hormon of hypophisishypophisis

Sperm maturity and Sperm maturity and transport pathwaytransport pathway

Tubuli recti et rete testisTubuli recti et rete testis EpididymisEpididymis Ductus deferensDuctus deferens Ejaculatory ductEjaculatory duct

Tubuli recti et rete testisTubuli recti et rete testis

cuboideal Sertoliho cellscuboideal Sertoliho cells no spermatogenic cellsno spermatogenic cells

surrounded by lymphatic channels, surrounded by lymphatic channels, blood vessels and Leydig cellsblood vessels and Leydig cells

EpididymisEpididymis

Ductuli efferentes - in headDuctuli efferentes - in head• columnar epitheluim with stereocilia columnar epitheluim with stereocilia

and ciliaand cilia– non-motile spermnon-motile sperm– scalloped outlinescalloped outline

• smooth muscle layersmooth muscle layer

EpididymisEpididymis

Ductus epididymidis - in body & tailDuctus epididymidis - in body & tail• highly coiled one tubule - 4-6 m longhighly coiled one tubule - 4-6 m long• pseudostratified columnar epi with pseudostratified columnar epi with

stereociliastereocilia• two layers of smooth muscle - thickertwo layers of smooth muscle - thicker

functionfunction• maturationmaturation• storagestorage• transporttransport

Spermatic cordSpermatic cord

Vessels, muscles, lymphatic Vessels, muscles, lymphatic vessels, nervesvessels, nerves

Ductus defernes (Vas deferens)Ductus defernes (Vas deferens)• pseudostratified columnar epipseudostratified columnar epi• lamina proprialamina propria• 3 layers of smooth muscle (L, C, L)3 layers of smooth muscle (L, C, L)

Ejaculatory duct + Ejaculatory duct + AmpullaAmpulla

pseudostratified columnar epipseudostratified columnar epi lamina proprialamina propria muscular layer only in ampullamuscular layer only in ampulla

Accesory Genital glandsAccesory Genital glands

Seminal vesiclesSeminal vesicles ProstateProstate Bulbourethral glandsBulbourethral glands

Seminal vesicles Seminal vesicles (Glandulae vesiculosae)(Glandulae vesiculosae)

cuboidela-to-pseudostratified epicuboidela-to-pseudostratified epi folded mucosafolded mucosa smooth muscle layer (C+L)smooth muscle layer (C+L) adventitia + serosa on apex !adventitia + serosa on apex ! function: 50-70% of seminal fluidfunction: 50-70% of seminal fluid

• fructosefructose

ProstateProstate

30-50 tuboalveolar glands in 30-50 tuboalveolar glands in fibromuscular stromafibromuscular stroma

3 regions of glands3 regions of glands• periurethral mucosal gl.periurethral mucosal gl.• periurethral submucosal gl.periurethral submucosal gl.• peripheral main gl.peripheral main gl.

ProstateProstate

simple-to-pseudostratified episimple-to-pseudostratified epi prostatic concrements (corpora prostatic concrements (corpora

amylacea)amylacea)• protein rich material, calcificationsprotein rich material, calcifications

function: enrich the semen fluid, function: enrich the semen fluid, fibrinolysin, amylase, PSAfibrinolysin, amylase, PSA

Bulbourethral glandsBulbourethral glands

mucus secreting glandsmucus secreting glands +galactose+galactose lubrication functionlubrication function

PenisPenis

three masses of erectil tissuethree masses of erectil tissue• 2x corpora cavernosa2x corpora cavernosa• 1x corpus spongiosum1x corpus spongiosum

communicating blood spaces (sinuses) communicating blood spaces (sinuses) surrounded by connective tissuesurrounded by connective tissue

artery -> sinus -> veinartery -> sinus -> vein dilatation of artery (NO) compress vein, dilatation of artery (NO) compress vein,

sinuses fill with blood -> erection occurssinuses fill with blood -> erection occurs