Male Reproductive Histology Flashcards
What produces sperm and androgen?
Testes
What transports sperm?
epididymis, ductus deferens, ejaculatory duct, urethra
semen production and sperm nutrient source?
seminal vesicle
prostate gland
bulbourethral glands
Testes?
1) responsible for what?
2) where are they located and what holds them there
3) closely associated with what
4) what is it surrounded by, include both layers
5) what can we find inside the testicle itself?
responsible for producing sperm
located in the scrotum which is important for keeping the sperm at an appropriate temperature
it’s closely associated with the epididymis.
it’s surrounded by the tunica albuginea (dense CT capsule)
deep to this in the actual testes are seminiferous tubules, which is where sperm production is going to take place
more superficial to the tunica albuginia is the tunica vaginalis (derived from the peritoneum)
more posteriorly the connective tissue organization changes into the “Rete testis”.. which is part of the way sperm can leave the testes and be transported to the epididymis
Seminiferous Tubules?
how many are there?
what is within each tubule?
what do both of these cells make up?
What surrounds the seminiferous tubules and what do they do?
highly convoluted and one tube in each lobule.
within each tubule you’ll see Somatic Sertoli cells, and Spermatogenic cells
organization of sertoli and spermatogenic make up the seminiferous epithelium.
these tubules are surrounded by peritubular myoid cells.. these are contractile that propel spermatazoa out of the tubules to the rete testis.
What’s found between the seminiferous tubules?
Interstitial cells of Leydig
What do Sertoli cells have?
hallmark?
what can be seen going from Sertoli cell to Sertoli cell?
they have these cytoplasmic pockets that the developing sperm that will embed themselves in, and that helps to aide in sperm development and the changes they undergo as they go from beginning form to sperm.
have a very large nucleus, and in the middle is a “cyclops nucleus”
they make junctional complexes to each other.
what is the sertoli-sertoli complex?
what do they create?
what happens to someone f the developing spermatogonia?
significant amount of tight junctions that are established between Sertoli cells to create a barrier from the basal surface of the epithelium and to separate that from the luminal surface.
so separates the basal and luminal compartment.
some of the developing spermatogonia remain in the basal compartment and be shifted to the luminal compartment
why is the sertoli-sertoli complex important?
what cell type is isolated from systemic circulation?
this creates the “blood testis barrier”
blood flow is on the outside of the tubule in the interstitial area.. in the luminal area there is developing spermatotids.. so it permits the developing spermatocytes to be blocked from any sort of signaling from the vasculature. once the cells move out into the luminal compartment they’re haploid..
so it isolates the haploid germ cells from systemic circulation (i.e. immune system) (secondary spermatocytes, spermatids, sperm)
how do cells move from the basal compartment to the luminal compartment if we have tight junctions?
what’s present in each compartment?
the junctions break and cells get shifted and push out towards that luminal area..
spermatogonia and primary spermatocytes are found in the basal compartment
when the primary spermatocyte is formed it’s pushed through the junctional complexes where it transitions to later stages.
luminal compartment has more mature spermatocytes and early/late spermatids.
What type of “genesis” of the cells happen in the luminal compartment?
meiosis and spermiogenesis
why are Sertoli cells called “nurse cells”?
1) what do they provide for the sperm?
2) what do they do cleaning up the area?
take care of the developing sperm.
the provide nutrients and remove waste..
but also phagocytose residual bodies (spermatogenesis) and spermatogenic cells that fail to differentiate!
what’s to note about spermatogonia as it goes from basement membrane to being more developed?
spotted, speckled chromatin are the primary spermatocytes and spermatogonia
as the cells continue to develop and move to the lumen the nuclei become more uniform = early spermatids
at some point the nuclei become elongated and pushed out.. those are LATE spermatids.
What does the blood testis barrier separate division wise?
haploid from diploid
Interstitial cells?
1) what do they do,
2) where are they found,
3) why are there white granules inside?
cells that are present in the interlobular space very close to the blood supply
these are steroid producing cells that produce 95% or so of the testosterone.
androgens don’t stain very well
what is the spermatogenic cell sequence?
2 types of spermatogonia and what do they do? what kind of division do they do?
what do you get from one of the spermatogonia? what does this now start dividing by?
from 1*, what happens until sperm?
Type A spermatogonia –> those that are truly sperm stem cell.. these divide to produce its own copy of itself and a type B.
Type A remains in the basal compartment as the precursor MITOSIS
Type B move on in their purpose and start to divide to produce primary spermatocytes through MITOSIS
right after that first division they enter meiotic prophase as a primary spermatocyte.. it will then be pushed out!
Spermatocytes divide by meiosis to form primary spermatocytes –> 2ndary spermatocytes (2 of them) –> differentiate to early Spermatids –> late spermatid.
