00:01
So what exactly does testosterone
affect?
First testosterone is synthesized
from cholesterol
and is transformed
at certain target cells.
00:13
There it is converted to DHT or
dihydrotestosterone in the prostate,
and also to estradiol
in the brain neurons.
00:24
It also prompts spermatogenesis
and targets all accessory organs.
00:30
These include the ducts,
the glands,
and also the penis,
causing them to grow to adult size
and adult function.
00:41
The testosterone also has
multiple anabolic effects
throughout the body
by targeting specific genes
that will produce certain proteins
and target cells.
00:54
A deficiency in testosterone leads
to atrophy of accessory organs.
01:00
Also the semen volume will decline
and erection and ejaculation
are impaired.
01:08
Usually this is treated by
testosterone replacement.
01:14
So testosterone
also is going to affect
male secondary sex characteristics.
01:21
These features are induced
in non-reproductive organs
by testosterone.
01:27
These include things like
the appearance of:
pubic, axillary and facial hair.
01:34
Enhance growth of the chest hair,
and the deepening of the male voice.
01:39
The thickening of the skin
and also the skin can sometimes
become more oily,
which usually predisposes a
postpubescent male to acne
and things like that.
01:52
Also, the bones are going to
grow in length
and also increase in density.
01:59
Skeletal muscle will increase
in size and mass.
02:04
Also, testosterone can lead to
a boost in the basal metabolic rate
or your metabolism.
02:13
And also testosterone
can be the basis
of the sex drive or libido in males.
02:21
So as we can see,
testosterone masculinizes
the embryonic brain
and continues to exert
that effect well into adulthood.
02:32
And the testes
are not the only place
where testosterone
is going to be produced.
02:38
For example,
it's also produced
by the adrenal gland.
02:43
But although the adrenal gland
has the ability
to produce androgens
in small amounts,
the production in the adrenal gland
is not sufficient enough
to maintain normal testosterone
mediated functions.