組織學(xué)與胚胎學(xué)15 男性生殖系統(tǒng)

MaleReproductiveSystem男性生殖系統(tǒng)Testes

Genitalducts:生殖管道Epididymis,附睪睪丸

Ductusdeferens,輸精管Ejaculatoryducts射精管Urethra尿道Accessoryglands:附屬腺

Seminalvesicles,精囊Prostate,前列腺Bulbourethralgland尿道球腺PenisIntroduction2TESTESI.GeneralStructure:Tunicavaginalis(mesothelium)漿膜(鞘膜臟層）Tunicaalbuginea白膜&mediastinumtestis

縱隔Testicularlobules睪丸小葉Seminiferoustubule生精小管Straighttubules直精小管retetestis睪丸網(wǎng)Interstitialtissue&LeydigcellFunction:Producesperm&sexualhormone34

spermatogeniccellsSpermatogenicepitheliumsupportingcellsBasementmembraneFewcollagenandmyoidcells:

扁平、肌動蛋白或類肌動蛋白樣物質(zhì)收縮→精子移動分泌多種生長因子→調(diào)節(jié)睪丸的功能

seminiferoustubule

生精小管

D=150-250um,30-70cmlong,生精上皮生精細(xì)胞支持細(xì)胞5SeminiferousTubules6Limitingm.SertoliCellSpermatogenicepitheliumInterstitialtissue&Leydigcell789(l)Spermatogeniccell&Spermatogenesis

生精細(xì)胞和精子的發(fā)生

●Spermatogeniccellsdifferentiatetospermatozoa

●Successivespermatogeniccells:

spermatogoniaprimaryspermatocytesecondaryspermatocytespermatidsspermatozoa.Spermatogenesis:Theprocessfromspermatogoniatospermatozoa.10

Spermatogonium精原細(xì)胞

Themostimmaturespermatogeniccell,onB.M.Round&small(12um),aroundnucleusw/l-2nucleoli&finely-granulatedchromatin.(l)spermatogoniaA(stemcells);(2)spermatogoniaB,primaryspermatocyt初級精母細(xì)胞(Atsexualmaturity,aseriesofsuccessivemitoses)111213Primaryspermatocyte

初級精母細(xì)胞

Inmiddlezoneoftheepithelium.Easytoseeninsection(thefirstmeiosisneed22days)Thelargestone(16-18um),nucleusw/prominentchromosomes,46(44+XY)&4NDNA.

Primaryspermatocyte→→→Secondaryspermatocyte（by1stmeiosis）

1415Secondaryspermatocyte

次級精母細(xì)胞Nearlumen.Difficulttoobserveinsection(thesecondmeiosisquicklycompleted).Round(12um)&apale-stainednucleus,23(22+Xor22+y)&2NDNA.次級精母胞不進(jìn)行DNA復(fù)制，即進(jìn)入第二次成熟分裂，由于次級精母細(xì)胞存在時(shí)間短，故在生精小管切面中不易見到。Secondaryspermatocyte→→→spermatids（by2ndmeiosis）

16Spermatid精子細(xì)胞Closetolumen.spherical(6um).23(22+Xor22+Y)&1NDNA(haploid)17Spermiogenesis精子形成Acomplexprocessthataroundspermatidtransformsintoatadpole-likespermatozoon(nofurtherdivision)occurs).

18(a)Golgiapparatusacrosomalgranuleacrosomalvesicleacrosomalcapacrosome(covers2/3ofthenucleusanteriorly)(b)Condensationofchromatinaelongated&flattenednucleus.(c)Acentrioleaflagellum(axoneme)Attheposteriorpoleofthenucleus(formotility).(d)Mitochondriaasheathofmitochondria.Spiralaroundinitialpartofthetail(e)Partsofthecytoplasmcastoffasaresidualbodies(phagocytizedbySertolicells).(a)Golgiapparatusacrosomalgranuleacrosomalvesicleacrosomalcapacrosome頂體

(covers2/3ofthenucleusanteriorly)(b)Condensationofchromatinaelongated&flattenednucleushead

(c)Acentriole中心粒

aflagellum(axoneme)軸絲

Attheposteriorpoleofthenucleus(formotility).鞭毛（尾部）(d)Mitochondria線粒體

asheathofmitochondria.Spiralaroundinitialpartofthetail(e)unnecessarycytoplasmcastoffasaresidualbodies(phagocytizedbySertolicells).1960umlong,consistofahead&atail.Head:pear-shaped&flattenedw/anuclear&aacrosome(containshydrolyticenzyme).Tail:55uminlength（尾部是精子的運(yùn)動裝置）Subdividedinto4segments:(a)neck,containingacentriole頸段短，其內(nèi)主要是中心粒，由中心粒發(fā)出9＋2排列的微管，構(gòu)成鞭毛中心的軸絲(b)middlesegment(5-7um),containingasheathofmitochondria軸絲外側(cè)有9根縱行外周致密纖維，外側(cè)再包有一圈線粒體鞘，為鞭毛擺動提供能量，使精子得以快速向前運(yùn)動(c)principalsegment(45um),containingafibroussheath(supportthetail).主段最長，軸絲外周無線粒體鞘，代之以纖維鞘

(d)endpiece(5-7um),short,axialfilamentsonly末段短，僅有軸絲

spermatozoon精子202122SpermatocytogenesisMeiosisSpermiogenesisprimarysecondaryspermatidsspermatozoa23Spermatogenesis:

精子發(fā)生

spermatogoniaprimaryspermatocytes

bymitosis

B.Meiosis:

Spermatocytesspermatids,through2succeesivemeiosisw/reductionbyhalfnumberofchromosomes&halfamountofDNApercellC.

Spermiogenesis:精子形成

Spermatidsspermatozoabymodifyingstructures&shape(nodivision).summary24ThePassageoftheSpermSeminiferoustubulesstraighttubulesretetestisefferentductules

genitalducts25(2).Sertolicells:支持細(xì)胞

ColumnarcellrestonB.M.,thefreesurfacereachestolumen.spermatogeniccellslocateb/wadjacentcells

Features&function:LM:

noclearoutline,ovoidnucleusw/adistinctnucleolus.EM:

(l)abundantsER.,Gl.,Ly.,Mf.,&Mt.(2)Tightjunctionspresentb/wadjacentSertolicells(isolatespermatogoniafromotherspermatogeniccells).2627Tightjunctionbasalcompartment（基底室）

abluminalcompartment（近腔室）28Function:

(l)Support&nourishspermatogeniccells;(2)Secretefluidtohelpthespermmoving;(3)Phagocytize吞噬&digesttheresidualbodies(4)Synthesize&secreteABP(androgenbindingprotein雄激素結(jié)合蛋白)whichcombinesandrogeninseminiferoustubuletostimulatespermatogenesis;，以保持生精小管內(nèi)雄激素的水平，促進(jìn)精子發(fā)生

Inhubin（抑制素）→pituitarysecreteFSH(5)Formtheblood-testisbarrier血－睪屏障:Tightjunctlonconstitutethemainpart29blood-testisbarrier

血睪屏障

Endothelialcellandit’sbasementmembraneCTBasementmembraneofspermatogenicepitheliumTightjunctionbetween

sertolicellsFnction:separatesgermcellsfromimmunesystem&preventsauto-immunereaction.可阻止某些物質(zhì)進(jìn)出生精上皮，形成并維持有利于精子發(fā)生的微環(huán)境，防止精子抗原物質(zhì)逸出到生精小管外而發(fā)生自體免疫反應(yīng)。30III.Interstitialtissue睪丸間質(zhì)B/wseminiferoustubulesL.c.t.w/smallb.v.&l.v.,nerves&Intersitialcell

:(間質(zhì)細(xì)胞）

Leydigcella.ingroups&nearb.v.;b.large,roundorpolygonal,acidophilic,roundnucleusw/prominentnucleolus.c.EM:abundantsER,tubularcristaeMit.,lipiddroplets313233Function:secrete

androgen（雄激素）forproliferation&differentiationofgermcells,fordevelopmentofgenitalsystem,formaintenanceofmalesecondarysexcharacteristics.34IV.Regulationoftesticularfunction:1.Intersitialcell

arecontrolledbyinterstitialcellstimulatinghormone(ICSH);2.Folliclestimulatinghormone(FSH)regulatesthefunctionofsupportingcells3.ICSH&FSHaresecretedbycellsinglandularpituitary.35Tubulerectusandretetestis直精小管和睪丸網(wǎng)Tubulerectushortandstaight，thinsimplelowcolumnarnospermatogeniccells。Retetestis：inmediastinumtestislumenlargeandirregularsimplecuboidal3637Epididymis附睪I.Ahead,abody&atail.II.ConsistofEfferentduct輸出小管andEpididymalduct附睪管頭部主要由輸出小管組成，體部和尾部由附睪管組成38Efferentduct輸出小管

IrregularlumenTallciliatedcolumnarcell：高柱狀纖毛細(xì)胞ciliaswingacceleratetransportofspermsecreteLowcolumnarcell：低柱狀細(xì)胞absorbanddigestsubstanceinsidethelumen39Epididymalduct

(附睪管)：Pseudostratifiedcolumnarepithelium，

RegularlumenLargenumbersofsperm。Chifecell主細(xì)胞：

tallcolumnar，stereocilia（靜纖毛）；

—secreteandpynocytosisBasalcell基細(xì)胞：

pyramidal

—pynocytosis40414243

Function:AbsorbmostofthefluidthatleavesthetestisSecretecarnitine肉毒堿,glycerylphosphoryo-choline甘油磷酸膽堿,sialicacid唾液酸