male reproductive system consists of the testes, penis, ducts that
connect them, and accessory glands or prostate gland. The two testes
are oval shaped organs that hang between the legs in the scrotum.
The testes produce sperms which are capable of swimming in order to
look for the egg they have to fertilize.
The testes since are present in the scrotum have a temperature lower
than the body's by about 5 degree F or 3degree C. this is optimal
for sperm production. Daily several million sperms are produced
puberty onwards. The production and maturation of each sperm takes
about 2 months. Each second millions of sperms are made in the
seminiferous tubules, from where they pass to the epididymis to
mature. The production is controlled by- luteinizing and follicle
stimulating hormones (LH and FSH). The penis is a tube shaped organ
that facilitates the tranfer of sperm into the female vagina during
intercourse.. the penis has three layers of spongy tissue that
enables it to become erect. The urethra present in the penis carries
both the urine and semen to the outside.
Vas deferens carries the mature sperm
from the epididymis to the urethra, which it joins just below the
bladder. Emptying into each vas deferens, just behind the bladder,
is a seminal vesicle. Seminal vesicle and prostate gland, which
surrounds the urethra where it leaves the bladder, produce
secretions that mix to form semen. Semen acts as a fuel provider and
as a carrier for the sperms.
Erection process: The penis needs to become erect so
that it can be inserted in the vagina. Erection makes the penis
stiff and increases its length considerably. The erection is a
reflex action controlled by the Autonomic Nervous System. During
sexual arousal, arterioles supplying the penis get wider, resulting
in increased blood flow. This fills the spaces in the spongy
cylinders inside the shaft and the glans penis, making the penis
expand and become stiff.
Ejaculation process: Ejaculation is also a reflex action
controlled by the Autonomic Nervous System. It is triggered when the
sexual act reaches a critical level of excitement. It has two
phases- in the first, the vas deferens contract to squeeze the sperm
towards the base of the penis, and the prostate gland seminal
vesicles release their secretions to make semen. At this stage the
ejaculation is unstoppable. In the second, muscles at the base of
penis cotract every 0.8 seconds and force the semen out of the penis
in upto 5 spurts. Almost 5 ml of semen is released.
Did you know?-----
There are about 300 million sperms in each ejaculate i.e. about 5 ml
of semen and only one sperm is enough to fertilize the egg.