Male Reproductive System Flashcards
What is the thick capsule of dense irregular CT covering each testis?
Tunica Albuginea
What two components does the testicular lobules consist of?
seminiferous tubules
interstitial tissue
Where is the site of spermatogenesis?
Seminiferous Tubules
What 2 cells are within the stratified germinal epithelium of the seminiferous tubules?
Spermatogenic cells
Sertoli cells
What is the function of Myoid cells?
contractile properties that help move spermatozoa and testicular fluid through seminiferous tubules
What does spermatogenesis require?
Testosterone
What are spermatogonia and what are the different types?
Diploid sperm that begin dividing by mitosis at puberty
- -Type A–continue dividing to produce stem cells/progenitor cells
- -Type B– progenitor cells that divide into primary spermatocytes
What are primary spermatocytes?
Generated from type B spermatogonia
–enter prophase of first meiotic division and remain for 22days–most primaries will be in prophase
Ultimately each will produce 4 haploid gametes
What are secondary spermatocytes and how are they formed?
generated through reduction division–meiotic division of primary spermatocytes
Short lived–so can’t find on section
Undergo second meiotic division–sister chromatids separate into the resulting 2 spermatids
What are spermatids and what do they differentiate into?
Haploid sperm that differentiate into spermatozoa via spermiogenesis
What are the changes that occur during spermiogenesis and what are the spermatids physically attached to during this process?
Spermatids are physically attached to Sertoli cell plasma membrane
Acrosome formation– cap which contains hydrolytic enzymes that dissociate cells of the corona radiate and digest the zone pellucid of the oocyte
Flagellum formation– Centrioles–initiate microtubule assembly then mitochondria aggregate
Nuclear changes–condenses/elongates/moves anteriorly
Change in orientation– Reorients so head points toward basal lamina and flagellum extends into lumen
Later changes- excess cytoplasm (residual body) phagocytosed by Sertoli cells—spermiation–spermatids released as spermatozoa
Describe Acrosome formation?
cap which contains hydrolytic enzymes that dissociate cells of the corona radiate and digest the zone pellucid of the oocyte
Describe Flagellum formation?
Centrioles–initiate microtubule assembly then mitochondria aggregate
Describe nuclear changes?
condenses/elongates/moves anteriorly
What changes in orientation occur spermiogenesis?
Reorients so head points toward basal lamina and flagellum extends into lumen
What is residual body and how is it taken care of?
Excess cytoplasm–phagocytosed by Sertoli cells
What is spermiation?
Spermatids released from Sertoli cells and from each other into lumen as spermatozoa
What are the functions of Sertoli cells?
- -Support/protection/nutrition to developing spermatozoa
- -Phagocytosis–of residual bodies and degenerating spermatogenic cells that failed to differentiate completely
- -Secretion–for sperm transport also androgen binding protein and hormones (inhibin) that regulate release of FSH
- -Blood-Testis barrier–created by tight junctions btwn Sertoli cells
What are Leydig cells and what do they do?
Steroid producing cells that become apparent during puberty
Produce 95% of testosterone in males
Stimulated to produce testosterone by LH
What concentrates testosterone in seminiferous tubules?
Androgen binding protein secreted by Sertoli cells
What is cryptorchidism and what does it affect?
failure of one or both testes to descend into the scrotum
Affects spermatogenesis
What are straight tubules?
Join seminiferous tubules to rete testis
lined with epithelium consisting of only Sertoli cells or simple cuboidal cells
What are Rete Testis?
connects straight tubules to efferent ductules
lined with simple epithelium–varies from squamous to low columnar
Produces some testicular fluid for sperm transport
What are Efferent ductules?
connects rete testis to ductus epididymis
lined with simple epithelium that appears scalloped due to non-ciliated cuboidal cells and ciliated tall columnar cells(contain ONLY true cilia in the male reproductive system)
