A presentation explaining the production and control of rate of spermatogenesis in human males.

1. Spermatozoa-
immature sperm
cells
Leydig cells (between tubules, in
connective tissue) - Leutinising
Hormone (LH) stimulates these
cells to synthesise and secrete
testosterone. This testosterone
can then stimulate the Sertoli
cells to initiate spermatogenesis.
Topic 1: The regulation of testosterone production and rate of spermatogenesis through hormones
and negative feedback.
Connective tissue
capsule
Capillary
The diagram shows a
cross section
through a single
seminiferous tubule.
Blood-testis barrier (dotted line)
Sertoli cell nuclei (within
tubule). The
hypothalamus secretes
Gonadotropin Releasing
Hormone (GnRH) which
stimulates both
Luteinising Hormone (LH)
and Follicle Stimulating
Hormone (FSH) to be
synthesised and secreted
by the gonadotropic cells
of the anterior pituitary
gland. FSH binds to Sertoli
cells and stimulates
spermatogenesis.
Fibroblast
Luminal compartment –
where spermatogenesis
occurs.

2. Topic 1:
Male reproductive hormones regulate testosterone levels and spermatogenesis.
The diagram shows a
cross section
through a single
seminiferous tubule.
Furthermore, with the release
of inhibin, testosterone is not
stimulated to be produced by
Leydig cells which brings down
blood level of testosterone. This
means Sertoli cells regulate rate
of spermatogenesis using
negative feedback control.
Both the release of
inhibin by Sertoli cells
when sperm count is too
high and too much
testosterone acting on
the hypothalamus and
pituitary gland inhibits
the release of GnRH, FSH
and LH. This means less
spermatogenesis occurs.
Lower sperm count will
cease the secretion of
inhibin so levels of GnRH,
FSH and LH increase, so
spermatogenesis and
levels of testosterone
increase.

3. References
Sofikitis, N., Giotitsas, N., Tsounapi, P., Baltogiannis, D., Giannakis, D., &
Pardalidis, N. (2008). Hormonal regulation of spermatogenesis and
spermiogenesis. The Journal of steroid biochemistry and molecular
biology, 109(3-5), 323–330.
https://doi.org/10.1016/j.jsbmb.2008.03.004
• Tortora, G. J. (2013). Principles of Anatomy and Physiology 14e with
Atlas of the Skeleton Set(14th ed.). Wiley.
https://r1.vlereader.com/Reader?ean=9781118808511