REPRODUCTIONS SYSTEM

Do you know about reproductions system? Well, reproduction system is something what should you to know because it’s very important for us specially for the teens. Most species have two sexes: male and female. Each sex has its own unique reproductive system. They are different in shape and structure, but both are specifically designed to produce, nourish, and transport either the egg or sperm.

First, I will explain about the reproductions of male. In the reproduction of male there are:

• Two Testicles or testes = produce and store millions of tiny sperm cells. The testicles are oval-shaped and grow to be about 2 inches (5 centimeters) in length and 1 inch (3 centimeters) in diameter.
• Epididymis = a set of coiled tubes (one for each testicle) that connects to the vas deferens.
• vas deferens = a muscular tube that passes upward alongside the testicles and transports the sperm-containing fluid (semen)
• Scrotum = This bag of skin helps to regulate the temperature of testicles, which need to be kept cooler than body temperature to produce sperm.
• Seminal Vesicles = the vas deferens to the side of the bladder and provide fluids that lubricate the duct system and nourish the sperm.
• Prostate Gland, which produces some of the parts of semen, surrounds the ejaculatory ducts at the base of the urethra just below the bladder.
• Urethra = the channel that carries the semen to the outside of the body through the penis. The urethra is also part of the urinary system because it is also the channel through which urine passes as it leaves the bladder and exits the body.
• Penis = actually made up of two parts: the shaft and the glans . The shaft is the main part of the penis and the glans is the tip (sometimes called the head). At the end of the glans is a small slit or opening, which is where semen and urine exit the body through the urethra. The inside of the penis is made of a spongy tissue that can expand and contract.

When puberty begins, usually between the ages of 10 and 14, the pituitary gland (which is located near the brain) secretes hormones that stimulate the testicles to produce testosterone. The production of testosterone brings about many physical changes. Although the timing of these changes is different for every guy, the stages of puberty generally follow a set sequence.

• During the first stage of male puberty, the scrotum and testes grow larger.
• Next, the penis becomes longer, and the seminal vesicles and prostate gland grow.
• Hair begins to appear in the pubic area and later it grows on the face and underarms. During this time, a male’s voice also deepens.
• Boys also undergo a growth spurt during puberty as they reach their adult height and weight.

Second, I will explain about the reproductions of female. In the reproductions of female there are:

• Vulva = Located between the legs, the vulva covers the opening to the vagina and other reproductive organs located inside the body.
• Mons pubis = The fleshy area located just above the top of the vaginal opening.
• Labia = Two pairs of skin flaps surround the vaginal opening
• Clitoris = a small sensory organ, is located toward the front of the vulva where the folds of the labia join
• Urethra = between the labia (the canal that carries urine from the bladder to the outside of the body)
• Vagina = a muscular, hollow tube that extends from the vaginal opening to the uterus. The vagina is about 3 to 5 inches (8 to 12 centimeters) long in a grown woman. Because it has muscular walls it can expand and contract.
• Hymen = A thin sheet of tissue with one or more holes in it vagina.
• Uterus = The vagina connects with the cervix.
• Cervix = shaped like an upside-down pear, with a thick lining and muscular walls. In fact, the uterus contains some of the strongest muscles in the female body.
• Fallopian tubes = Connect the Cervix to the ovaries. The fallopian tubes are about 4 inches (10 centimeters) long and about as wide as a piece of spaghetti. Within each tube is a tiny passageway no wider than a sewing needle.
• Ovaries = are two oval-shaped organs that lie to the upper right and left of the uterus. They produce, store, and release eggs into the fallopian tubes in the process called ovulation

Toward the end of puberty, girls begin to release eggs as part of a monthly period called the menstrual cycle. Approximately once a month, during ovulation, an ovary sends a tiny egg into one of the fallopian tubes. Unless the egg is fertilized by a sperm while in the fallopian tube, the egg dries up and leaves the body about 2 weeks later through the uterus. This process is called menstruation. Blood and tissues from the inner lining of the uterus combine to form the menstrual flow, which in most girls lasts from 3 to 5 days.

Third, I will tell you about how the way of baby was born. When our parents was married and have a sex, they have plan to make a baby. If a female and male have sex within several days of the female’s ovulation (egg release), fertilization can occur. When the male ejaculates (which is when semen leaves a man’s penis), between 0.05 and 0.2 fluid ounces (1.5 to 6.0 milliliters) of semen

is deposited into the vagina. Between 75 and 900 million sperm are in this small amount of semen, and they “swim” up from the vagina through the cervix and uterus to meet the egg in the fallopian tube. It takes only one sperm to fertilize the egg.

About a week after the sperm fertilizes the egg, the fertilized egg (zygote) has become a multi-celled blastocyst . A blastocyst is about the size of a pinhead, and it’s a hollow ball of cells with fluid inside. The blastocyst burrows itself into the lining of the uterus, called the endometrium . The hormone estrogen causes the endometrium to become thick and rich with blood. Progesterone, another hormone released by the ovaries, keeps the endometrium thick with blood so that the blastocyst can attach to the uterus and absorb nutrients from it. This process is called implantation.

As cells from the blastocyst take in nourishment, another stage of development, the embryonic stage, begins. The inner cells form a flattened circular shape called the embryonic disk, which will develop into a baby. The outer cells become thin membranes that form around the baby. The cells multiply thousands of times and move to new positions to eventually become the embryo. After approximately 8 weeks, the embryo is about the size of an adult’s thumb, but almost all of its parts — the brain and nerves, the heart and blood, the stomach and intestines, and the muscles and skin — have formed.

During the fetal stage, which lasts from 9 weeks after fertilization to birth, development continues as cells multiply, move, and change. The fetus floats in amniotic fluid inside the amniotic sac. The fetus receives oxygen and nourishment from the mother’s blood via the placenta,  a disk-like structure that sticks to the inner lining of the uterus and connects to the fetus via the umbilical cord. The amniotic fluid and membrane cushion the fetus against bumps and jolts to the mother’s body.

Pregnancy lasts an average of 280 days — about 9 months. When the baby is ready for birth, its head presses on the cervix, which begins to relax and widen to get ready for the baby to pass into and through the vagina. The mucus that has formed a plug in the cervix loosens, and with amniotic fluid, comes out through the vagina when the mother’s water breaks.

When the contractions of labor begin, the walls of the uterus contract as they are stimulated by the pituitary hormone oxytocin. The contractions cause the cervix to widen and begin to open. After several hours of this widening, the cervix is dilated (opened) enough for the baby to come through. The baby is pushed out of the uterus, through the cervix, and along the birth canal. The baby’s head usually comes first; the umbilical cord comes out with the baby and is cut after the baby is delivered.

The last stage of the birth process involves the delivery of the placenta, which is now called the afterbirth. After it has separated from the inner lining of the uterus, contractions of the uterus push it out, along with its membranes and fluids.