Essay Sample about Reproductive System

The Male Reproductive System The release of FSH and LH stimulates cells in the testes to produce testosterone. FSH and testosterone stimulate the development of sperm. Once large numbers of sperm have been produced in the testes, the developmental process of puberty is completed. The reproductive system Is now functional, meaning that the male can produce and release active sperm. The main function of the male reproductive system is to produce and deliver sperm.

The Female Reproductive System The primary reproducuve organs In the female are the ovaries.The ovaries are located in the abdominal cavity. The main function of the female reproductive system Is to produce ova. In addition, the female reproductive system prepares the female's body to nourish a developing embryo. In contrast to the millions of sperm produced each day In the male reproductive system, the ovaries usually produce only one mature ovum, or egg, each month. Sperm Cell Head- which contains a highly condensed nucleus.

At the tip of the head is a small cap that contains an enzyme vital to the process of fertilization. Mldplece- which Is packed with energy-releasing mitochondria.Tail- which contains the flagellum, propels the cell forward. Puberty Puberty Is a period of rapid growth and sexual maturation during which the reproductive system becomes fully functional. At the end of puberty, the male and female reproductive organs are fully developed.

The start of puberty varies for everyone. It usually occurs any time between the ages of 9 and 15, and, on average, begins about one year earlier in females than in males. Puberty begins when the hypothalamus signals the pituitary to produce Increased levels of two hormones that affect the gonads.The two hormones are follicle-stimulating hormone (FSH) and luteinizing hormone (LH) which stimulate the testes or ovaries which begins puberty. Fertilization During the menstrual cycle, an egg develops and is released from an ovary.

Eggs develop within their follicles. Although a female Is born with thousands of Immature uterus is prepared to receive a fertilized egg. If the egg is fertilized, it is implanted in the uterus and embryonic development begins. If an egg is not fertilized, it is discharged, along with the lining of the uterus.Stages of the Menstrual Cycle Follicular Phase- The follicular phase begins when the level of estrogen in the blood is relatively low.

The hypothalamus reacts to low estrogen levels by producing a releasing hormone that stimulates the anterior pituitary to secrete FSH and LH. These two hormones travel through the circulatory system to the ovaries, where they cause a follicle to develop to maturity. As the follicle develops, the cells surrounding the egg enlarge and begin to produce increased amounts of estrogen. As the follicle produces more and more of the hormone, the estrogen level in the blood rises ramatically.Estrogen causes the lining of the uterus to thicken in preparation for receiving a fertilized egg. The development of an egg in this stage of the cycle takes about 10 days.

Ovulation- This phase is the shortest in the cycle. It occurs about midway through the cycle and lasts three to four days. During this phase, the hypothalamus sends a large amount of releasing hormone to the pituitary gland. This causes the pituitary gland to produce FSH and LH. The release of these hormones has a dramatic effect on the follicle: It ruptures, and a mature egg is released into one of he Fallopian tubes.

Luteal Phase- The luteal phase begins after the egg is released. As the egg moves through the Fallopian tube, the cells of the ruptured follicle undergo a change. The follicle turns yellow and is now known as the corpus luteum. The corpus luteum continues to release estrogen but also begins to release progesterone.

During the first 14 days of the cycle, rising estrogen levels stimulate cell growth and tissue development in the lining of the uterus. Progesterone adds the finishing touches by stimulating the growth and development of the blood supply and surrounding tissue.During the first two days of the luteal phase the chances that an egg will be fertilized are the greatest. This is usually from 10 to 14 days after the last menstrual cycle.

If an egg is fertilized by a sperm, the fertilized egg will start to divide by the process of cell division known as mitosis. After several divisions, a ball of cells will form and implant itself in the lining of the uterus. The embryo continues to grow by repeated mitotic divisions. Within a few days of implantation, the uterus and the growing embryo will release hormones that keep the corpus luteum functioning for several weeks.This allows the lining of the uterus to nourish and protect the developing embryo.

Menstruation- Within two to three days of ovulation, the egg will pass through the uterus without implantation. The corpus luteum will begin to disintegrate. As the old follicle breaks down, it releases less estrogen and less progesterone. The result is a decrease in the level of these hormones in the blood.

When the level of estrogen falls below a certain point, the lining of the uterus begins to detach from the uterine wall. This tissue, along with blood and the unfertilized egg, are discharged through the vagina.This phase of the cycle is called menstruation. Menstruation lasts about three to seven days on average.

A new cycle begins with the first day of menstruation. A few days after stimulate the hypothalamus. The hypothalamus produces a releasing hormone that acts on the pituitary gland, which then starts to secrete FSH and LH, and the cycle begins again. Sexually Transmitted Diseases STD's are diseases spread from one person to another during sexual intercourse. STD's can be caused by bacteria or viruses. Chlamydia and syphilis are caused by bacteria.

Chlamydia is the most common STD. Over three million cases occur every year. Chlamydia spreads by a bacteria that is passed from person to person during sexual contact. Syphilis is spread by sexual intercourse and can be a fatal disease. Both diseases can cause infertility and damage to sexual organs. Hepatitis B and AIDS are caused by viruses.

Unlike the bacterial STD's these diseases cannot be treated with antibiotics. The safest way to avoid STD's are through abstinence, the next best way is to use a latex condom.