How does Pregnancy Happen?

A girl is born with a hollow organ in her lower abdomen (Pelvis) called the Uterus. Two tubes extend from its sides (Fallopian tube) and each end with an oval organ called the ovary. A girl is born with a number of eggs in each ovary which reaches one million at birth, some die and only 400,000 eggs are left at puberty.

The egg consists of an ovum surrounded with layers of cells. At the beginning of each month the pituitary gland releases F.S.H hormone which to chooses some eggs in the each ovary to prepare them for fertilization by increasing their size. The growing eggs release ESTROGEN which prepares the endometrial cavity of the uterus and the cervical secretions. Usually one egg reaches the optimal size for fertilization, followed by release of L.H hormone from the pituitary which starts the maturation and ovulation process where the ovum breaks from its cover of cells and is released outside the ovary to be picked by the fimbrial ends of the fallopian tubes, this occurs at the middle of the month approximately. The egg leaves behind the layers of cells (Sac) which used to surround it (Yellow body now); this sac releases PROGESTERONE which supports pregnancy if it happens.

The man is born with his organs outside his body. On the outside it consists of a penis and scrotum which contains the testis, while inside it consists of the prostate and the seminal vesicles. The L.H hormone from the pituitary helps in production of TESTESTERONE hormone. F.S.H and TESTESTERONE together help in production of sperms from the testes. The prostate and seminal vesicles release the seminal fluid which offers nutrients for the sperms. The sperms move towards the spermatic cord where it mixes with the seminal fluid and is ejaculated outside from the penis during intercourse.

Pregnancy happens after the ability of the male to produce healthy sperms and the female healthy eggs, Release of the ovum to be picked by the tubes, Ability of the sperms to move from the vagina through the secretions of the cervix and continues its way through the uterus to the tubes till it meets the egg and fertilizes it. Cell cleavage happens while moving towards the uterine cavity. Two cells after 30 hours, 4 cells in 48 hours, 8 cells in 72 hours then the morula and blastocyst at 5 days. The blastocyst starts to implant into the endometrial cavity on the sixth or seventh day.