The
Reproductive System of a woman
The
Menstrual Cycle
The
Hormones
The
Reproductive System of a Man
The
Role of Testosterone
The
Sperm's Odyssey in the Female Reproductive Tract
The
Process of Fertilisation
The Role of Testosterone
As already mentioned, the main male
sex hormone is testosterone and this is made by the testicles, starting
at puberty. Testosterone is produced by specialised cells in the testis
called the Leydig cells. These are stimulated to release testosterone in
response to the LH signal from the pituitary. LH is luteinising hormone
- the same hormone found in women.
Note that there are two separate
compartments in the testis - and that the Leydig cells are outside the
spermatogenic tubules where the sperms are manufactured. This explains
why there is no relation between virility (which depends upon testosterone
production) and fertility (which depends upon sperm production).
Testosterone does more than just
allow men to make sperm. It also triggers the growth of facial hair, the
deepening of men's voices, and the development of a male physique - all
the changes which make boys into men. Testosterone is also important in
creating desire for sex - it increases libido.
In addition to the need for testosterone,
the production and maturation of sperm in the seminiferous tubules of the
testis is stimulated by FSH produced by the pituitary gland - and this
FSH is identical to that found in women.
