00:00
I show you this slide to illustrate
two points. Firstly, what is dominant in this
slide is the diagram. It shows you a mature
spermatozoon. It has got a head, a body,
and a tail. And it’s a reason from the whole
process of spermatogenesis that I’ve just
described. That process takes about 74 days.
One other point I want to emphasize before
we move on, and that is that when the spermatogonia
go through successive phases of mitotic division
coming from the very early stem cell I first
mentioned, when they divide, they don’t
entirely separate structurely. There is continuity
with their cytoplasm all the way through division,
and then all the way through the process of
the meiotic divisions I've described as well.
01:11
So the spermatogonia, dividing into a primary
spermatocyte, then a secondary spermatocyte,
and then going into this spermatid phase,
those spermatogenesis, all those cells, derived
from one particular spermatogonia, actually
are linked together. And so often when you look
at sections through the seminiferous tubule,
you’ll see regions of the tubule where you’ll
see one cell type predominantly, and that’s
because of this linking together of cells
going through various phases of spermatogenesis.