Information about The Mestrual Cycle/Ovulation, Spermatogenesis and

Fertilization

Menstrual cycle

Definitions Menstruation Definition: The monthly cycle of changes

in the ovaries and the lining of the uterus (endometrium), starting with the preparation of an egg for fertilization.

When the follicle of the prepared egg in the ovary breaks, it is released for fertilization and ovulation occurs. Unless pregnancy occurs, the cycle ends with the shedding of part of the endometrium, which is menstruation (“bleeding”). Although it is actually the end of the physical cycle, the first day of menstrual bleeding is designated as "day 1" of the menstrual cycle.

This is a picture of a close-up of the egg, or ovum (female sex cell), just before ovulation

Ovulation Definition: The release of the ripe

egg from the ovary. The egg is released when the cavity surrounding it (the follicle) breaks open in response to a hormonal signal. Ovulation occurs around fourteen or fifteen days from the first day of the woman's last menstrual cycle. When ovulation occurs, the ovum moves into the fallopian tube and becomes available for fertilization.

This is a picture of Semen containing millions of sperm swimming towards the opening of the cervix

Menstruation is mostly a 28 days cycle of changes in the ovaries and the lining of the uterus (endometrium), starting with the preparation of an egg for fertilization. When the follicle of the prepared egg in the ovary breaks. The egg releases for fertilization and ovulation occurs. Unless women pregnancy occurs, the cycle ends with the shedding of part of the endometrium, which is menstrua-tion (“bleeding”).

Although it is actually the end of the physical cycle, the first day of the menstrual bleeding is designated as “day 1” of the cycle. It is basically the cycle that women lay the egg to have the baby

The Cycle

• A mature egg gets released from the ovary• The mature egg goes down to uterus(it takes

about 12 to 24 hrs to go to fallopian tube)• If the egg is not fertilized by a sperm and begins to dissolve.

Here is a video on ovulation

Spermatogenisis

Definition

• The process occurring in the male gonad of sexually reproducing organism where in the undifferentiated male germ cells develop into spermatocytes, which then transform into spermatozoa.

Production of sperm begins at a male’s puberty, around the age of 13. Once a male reached puberty, he would produce millions and millions of sperm cells each day. A male will be signed to be physically mature is when they can reproduce.

The sign of reproduction is the erection with an ejaculation. Males that were physically mature would also experience nocturnal emission (wet dream). It means an ejaculation is released during sleeping. It takes a sperm about 70 days to fully grow.

Do you want to know how a sperm actually grow? At the beginning, sperm stays in the testicles, then travels through the epididymis. The sperm push themselves into the epididymis with their tails, that is when they complete their development. Sperm are stored in the testicles until an ejaculation. It takes sperm about 4 to 6 weeks to travel through the epididymis. Then the sperm will move to the vas deferens.

This is a picture of a close-up of one sperm cell being stored in the epididymis. Here the sperm grow tails (mature) and become capable of propulsion. From here the

billions of sperm will travel through the Vas deferens to the seminal vesicles where they will be engulfed in a nourishing fluid called semen

The seminal vesicles and prostate gland produce a whitish fluid called seminal fluid. It mixed sperm into the form of semen. Semen is pushed out of the male's body through his urethra during an ejaculation process. Each time a male ejaculates, this fluid (semen) contains up to 500 million sperm cells.

Fertilization

Definition

Fertilization Definition: Fertilization is the

process of combining the male gamete, or "sperm," with the female gamete, or "ovum." The product of this combination is a cell called a zygote.

Fertilized sperm can get the egg ready in the

the fallopian tube during a 6 to 12 hour period. When a sperm enters the egg (conception) and the embryo starts to form that is when fertilization happens. Two cells divide and become four, the four cells divide and become eight, and so on to form the structure of the eventual human body.

This is a picture of the successful sperm. Behold, the moment of conception

When the cluster of cells reaches the uterus and settle down into the lining of the uterus, it means it has become an embryo. When the cluster of cells reaches the uterus and SETTLE DOWN it is called implantation. It takes about seven days from fertilization to implantation.

This is a picture of the fertilized egg, now called an embryo,

embeds itself into the uterine wall where it

will grow for the duration of the

pregnancy. Here it is protected and

nourished.

From now on, the female body concentrates on the growth of the embryo and stops the cycle a few weeks after the baby is born. That is the reason why women cannot conceive again while they are pregnant. A woman can only have one pregnancy at a time, but this does not exclude the possibility of having more than one embryo or fetus at a time, e.g. twins. 8-10 days after ovulation a pregnancy test can be positive.

This is a picture of a fetus at 20 weeks

Bibliograpyh

Video - (Youtube)http://www.youtube.com/watch?v=nLmg4wSHdxQ&feature=player_embedded

Pictures - (http://deerparkhpe.wikispaces.com)http://deerparkhpe.wikispaces.com/7-1+HEALTH+2010-11

Info - (http://deerparkhpe.wikispaces.com)http://deerparkhpe.wikispaces.com/7-1+HEALTH+2010-11

By: Anja

Jin

Angela