Spermatogenesis-converted.pdf

spermatogenesis

2. SPERMATOGENESIS
Spermatogenesistheformationof
spermcells.Ittakesplaceinthe
semniferoustubules.

4. Diploidcellsthatbegintheprocessarelocatednearthe
outerwallofthetubules.
Thesecellsmultiplyconstantlybymitosis,andeach
dayabout3millionofthemdifferentiateintoprimary
spermatocytes,thecellsthatwillundergomeiosis
MeiosisIofaprimaryspermatocyteproduces
secondaryspermatocytes,eachwiththehaploid
numberofchromosomes(n=23).
MeiosisIIthenformsfourcells,eachwiththehaploid
numberofsingle-chromatidchromosomes(spermatids).

5. Aspermcelldevelopsby
differentiationofeachof
thesehaploidcellsand
graduallypushedtoward
thecenterofthe
seminiferoustubule.
Fromthere,itpassesinto
theepididymis,whereit
matures,becomesmotile,
andisstoreduntil
ejaculation

8. SPERMSTRUCTURE

9. MALEHORMONES ANDTHEIR
FUNCTIONS

10. CONT..

11. CONT..

12. CONT..

13. HORMONAL CONTROL OF
SPERMATOGENESIS

14. SEMEN
Semenisgreyopalescentfluid,which
consistsofsuspensionofspermatozoa
inseminalplasma.
Itismadeupofthesecretionsofall
accessoryglandsofthemalegenital
tract.

15. SEMEN

16. SEMEN

17. SPERMCOUNT
Itisapprox.20millionsperm/mL(60
millionsperms/ejaculation)
Azoospermia:meansnospermatocytes
(malesterility)
Oligozoospermia:<15millionsperms/mL
Polyzoospermia:>250millionsperms/mL

19. EJACULATION
Ejaculationisthedischargeofsemen
fromthepenis.
Duringorgasm,thesemenisforcefully
expelledfromthebodybystrong
muscularcontractionsofspermducts.

20. CONT..
Duringejaculation,eachofthe
componentsthatmakeupsemenmaybe
dischargedfromtheurethraina
sequence.
Thefirstpartismadeupoftesticular
component ofsemenfollowedby
secretionoftheprostate,lastlythe
secretionofthevesiclesareexpelled.

21. PATHWAY OFSPERM

22. PROCESSOFEJACULATION
Atthepeakofsexualarousal,musclesinthe
epididymis,seminalvesicles,prostategland,andvas
deferenscontract.
Atthesametime,asphinctermuscleatthebaseof
thebladdercontracts,preventingurinefromleaking
intotheurethrafromthebladder.
Anothersphincteralsocontracts,closingoffthe
entranceoftheurethraintothepenis.

23. Inthesecondstageofejaculation,the
expulsionstage,thesphincteratthebaseof
thepenisrelaxes,admittingsemenintothe
penis.
Simultaneously,aseriesofstrongmuscle
contractionsaroundthebaseofthepenis
andalongtheurethraexpelsthesemenfrom
thebody