Female Reproductive System
When a girl reaches the age of 13-15, she begins to ovulate or starts her period. This is the age of her sexual maturity, the age of sexual maturity in both male and female is called puberty. The female reproductive system is a complex and important system. The system serves three main functions: to store ova, to produce ova, and to keep a fertilized egg until it is ready to live on its own. What happens in this age? Puberty is marked by changes in the body for example, in the female the breasts start developing, pubic hairs also grow and you become way more moody.
The first menstruation in the life of a girl is called menarche. In the female, the internal genitals are the ovaries, the fallopian tubes, the uterus and the vagina. The ovary it is a paired organ. Each ovary of the adult female is an oval body and weight 2-8 grams. The ovum drops into the body cavity. The process is called ovulation; the ovum which is released in to abdominal cavity is pushed towards the oval funnel. The ovum finally enters the funnel and starts coming down the duct. The ovum is very small the size of a pinhead.
The ovary releases one ovum every 28 days. Next comes the uterus or womb, it is a hollow, pear-shaped muscular structure. Its upper broader portion is called the corpus uteri and the narrow portion is the cervix. The cavity of the womb is 7-8 centimeter long. The external genital parts of the female include the outer and the inner lips and the clitoris. The outer and inner lips close the openings of the vaginal tube, the vestibule. The clitoris is found in the pubic cleft. In menstruation eggs will never be implanted in the uterus in the unfertilized state.
After about two weeks of ovulation the uterus begins to contract. This sign is of undoing the preparations it had made to receive to have a baby. Upon the contraction of uterus, the blood capillaries rupture, and the blood flows out through the vagina. The blood along with tissue debris is called menses. Menstruation lasts for 3-4 days. Menstruation takes place 14 days after the ovulation. Again 14 days after menstruation, there is fresh ovulation. Both these processes stop once pregnancy had set in. There are post-fertilization changes like, mplantation after fertilization the reproductive organs are directed towards a different set of activities. As the fertilized egg goes down the oviduct, it going through mitotic cell division, it is a nonstop process, but for our convenience we divide the post-fertilization events in to a number of stages. When the cell forms a mass of cells there is no space within the group, it’s called the morula stage. The cells of morula rearrange in a manner to leave some space. This stage is called blastula; therefore it is blastula which is embedded in the uterus. This process is called implantation.
The wall of the uterus is thick and its wall has muscles, glands and blood capillaries. As the fertilized egg erodes into the uterine wall, there is some erosion of blood capillary. As a result the blood comes out and the blastula gets nutrition from that blood. This will develop in to fetus and finally a baby. When the blastula implanted in the uterus of the mother, it continues to grow by cell division. There important layers of cells develop. These are the germ layers. Membranes are developed and the outermost membrane of the embryo is formed and now called chorion.
The second covering of the embryo is amnion, which immediately surrounds the fetus and protects it. Within this covering there is an amniotic fluid which protects the embryo from shocks as well as any major trauma. There is an intimate contact between the blood vessels of the uterus and that of the fetus through the placenta. Umbilical cord serves as a link between the fetus and maternal circulation. When the embryonic development is completed, the baby is born. The baby is pushed out by the contraction of the uterine muscles; this is called birth.
Somewhere between 45-55 years the ovary stops releasing the egg. We can say that the ovary has become nonfunctional. Menopause is a normal part of a woman’s aging process. The ovaries stop releasing eggs, and menstrual periods stop. Most women experience menopause around age 50. Before to menopause, menstrual cycles often become off. The ovaries are less active to stimulating hormone and luteinizing hormone. To try to make up for the decreased response, the body produces MORE of these hormones. The level of these hormones will decrease.
The hormones produced by the ovaries include the different forms of estrogen, progesterone, and prolactin. The ovaries continue to produce small amounts of testosterone and some estrogen. The hormones produced by the pituitary gland are also decreased. Because hormone levels fall, changes occur in the entire reproductive system. The vaginal walls become less elastic, thinner, and less rigid. The vagina becomes smaller and shorter. When menstruation stops in a woman, it is taken for granted that she will not be able to have a child any more. Ending of menstruation is called menopause.