Capacitation means physiological changes or special activation of spermatozoa

Capacitation means physiological changes or special
activation of spermatozoa, which occurs with them in female sex way. It is the process by which enzymatic
secretions of the uterus and uterine tube of the female genital tract strips
glycoproteins from sperm cell membrane. Cholesterol of sperm plasma membrane is
removed during capacitation, which results in the increased fluidity of the
membrane that is required for the fusion of acrosomal membrane with the sperm
cell membrane. Only after such changes they begin to move toward. Capacitation
lasts about 7 hours.

Taxis – active
passage of spermatozoa. Chemotaxis (chemotropism)
– movement toward to the oocyte, which produces special chemical substances –
gamones. Reotaxis – is the sperm ability for advance against the current
of fluid secreting by the epithelium, which lines the cervix, uterus and
uterine tube (against the mucus flow in the uterine tube). Stigmotaxis – against the peristaltic contractions
of Fallopian tube.

Distant
interaction of germ cells is regulated by prostaglandins, fertilizing proteins
(androgamones, hynogamones), progesterone and pH.

Seminal
fluid of semen contains prostaglandins, which have pharmacodynamic action on
the smooth muscle of the uterus and uterine tube.

Prostaglandins
stimulate uterine contractions, rhyth mic contractions of uterine tube muscles
and smooth muscles at all. Thanks to these peristaltic contractions the ovum is
transported along the Fallopian tube to the uterine space.

Oocyte and
spermatozoa are moving from the opposite sites of female genital tract.
Spermatozoa are much rapid, however, to be counted for by their intrinsic
motility.

Prostaglandins
assist in spermatozoa movement through the uterus and tubes to the site of
fertilization in ampullar portion of the Fallopian (uterine) tube.

Fertilizing proteins promote chemotaxis. The chemical substances, which are
produced by the ovum and sperms, are known as gamones.

The oocyte
secretes 2 types of hynogamones: the first one
stimulates spermatozoa in opposite to second one, which agglutinates them.

Androgamones are produced by spermatozoa.
Androgamones of firs type blocks the movement of male germ cells and
androgamone II lyses the oocyte membrane.

Progesterone
is secreted by the corpus luteum of the ovary after ovulation and stimulates
the secretion of nutrient-rich fluid by mucosal epithelium of female
reproductive tract (glandular epithelium of uterine tube and cervix, and
uterine glands - crypts).

PH of surrounding environment has grait influence on the process of fertiluization. The
matter is, the average speed of spermatozoa in female body is at about 2-3 mm
per minute but it varies very much with different pH.

Sperms
move slowly in the acidic environment of the vagina, but move rapidly in the
alkaline medium of the uterus.

It was found that few motile spermatozoa may appear
in the ampulla of the uterine tube 5 minutes after their deposition near the
external uterine os,
however, it took up to 45 minutes to other spermatozoa to complete the journey.
Only about 200-500 sperms usually reach the site of fertilization. Most of them
degenerate and are resorbed by the female genital tract.