The Human Reproductive System Essay Example for Free

The Human Reproductive System Essay The human reproductive system requires both the female and male to procreate. Although the reproductive organs will function separately, they will not create another human being without each other. The Male Sperm   Ã‚  Ã‚  Ã‚   The male reproductive system is more external than the female. Sperm must be created to fertilize the female’s egg and this is done in the testes or testicles of the male. Sperm are mobile cells that contain the male’s chromosomes, to be passed on the offspring. There are hundreds of thousands of sperm produced during a male’s lifetime, all of which have the potential to fertilize an egg. Sperm die off and are recreated at the rate of 1% day and sperm that are released from the body live only a few hours. Scrotum The testes are contained in a fleshy pouch known as the scrotum, which hangs outside the male body in the groin area. The testes themselves are actually over 850 feet of tiny tubing, curled into two balls inside the scrotum. It is in these tubes that the sperm are formed. The scrotum is a highly sensitive area. Normal body temperature will kill the sperm due to their sensitivity to high temperatures; this is why the scrotum lies outside the body rather than internally. In cold weather, the scrotum will pull the testicles closer to the body to maintain the proper temperature. Once formed the sperm must pass through into the epidiymis, which is a larger tube that stores the sperm and lets them mature until it is time to be ejaculated into the female. The epidiymis is encased in the scrotum along with the testes. Ducts   Ã‚  Ã‚  Ã‚   When the sperm is ready to be ejaculated it leaves the epidiymis and travels through the vasa deferentia. The vasa deferentia extend from the epidymis and go around the bladder in many different directions. The ends of the vasa deferentia are called ejaculatory ducts. These ducts are located behind the bladder and empty into the urethra. Before the sperm reach the urethra they must also travel through the seminal vesicles, which are also located behind the bladder. Accessory Glands   Ã‚  Ã‚  Ã‚   The seminal vesicles are part of a group of accessory glands. The seminal vesicles add the semen that coats the sperm during ejaculation. The seminal fluid â€Å"contains mucus, amino acids, fructose as the main energy source for the sperm, and prostaglandins to stimulate female uterine contractions to move the semen up into the uterus.† (biology.clc.uc.ed, 2007)   Ã‚  Ã‚  Ã‚   Inside the body, at the beginning of the urethra, is the prostate gland. The prostate gland is considered an accessory gland and is the largest of these glands. It secretes directly into the urethra and mixes with the seminal fluid. The secretions of the prostate gland are high in alkaline. Alkaline neutralizes the acid left by urine and produced by the female body. It protects the sperm as they make their way through the female to the egg.   Ã‚  Ã‚  Ã‚  Ã‚   Hanging from the front of the abdominal cavity on the outside of the body, in front of the scrotum, is the penis. It is made from several cylinders of spongy, erectile tissue. When the male becomes sexually excited, the spongy tissue becomes filled with arterial blood and the veins, which allow this blood to drain off to other areas, seal off. This causes an erection, which is required for ejaculation. The erection is also required to be able to enter the female’s vagina and fertilize the egg. Running through the center of the penis is a hollow tube called the urethra. It allows semen or urine to be released from the body. The male reproductive system  Ã‚  Ã‚  Ã‚   http://emc.maricopa.edu/faculty/farabee/biobk/BioBookREPROD.html The Female   Ã‚  Ã‚  Ã‚  Ã‚   The female reproductive organs are internal and produce eggs rather than sperm. The eggs are produced in the ovaries, which are located on either side of the abdominal cavity. The â€Å"eggs† are not like chicken or other animal eggs but more like a collection of special cells. While a female has almost a half million eggs at birth, only about 500 will be released from the ovaries during the time that she is fertile and able to reproduce. Eggs   Ã‚  Ã‚  Ã‚   The eggs are formed with a process known as â€Å"meiosis†. This means that the egg only has half of the chromosomes needed to complete a new being. The process known as fertilization provides the other half of the needed chromosomes, thus giving the offspring half from each contributing parent. Of the hundreds of thousands of eggs a female is born with, only about 300 of these are ever released to be fertilized. Ovaries   Ã‚  Ã‚  Ã‚   The ovaries, located on either side of the abdominal wall, create the eggs that are released for fertilization. The ovaries are connected to the fallopian tubes and store the unused eggs as well.   Ovaries also produce the female hormone estrogen, which affects mood, weight and other aspects of the body. Fallopian Tubes From the ovaries are the fallopian tubes, which extend from the ovaries on each side and down into the females uterus. The fallopian tubes lead into the uterus where the fertilized egg will remain as it gestates. In the female human, hormones contribute to the egg being released into the fallopian tubes. This is normally limited to one egg per cycle. Ovulation   Ã‚  Ã‚  Ã‚   Ovulation is the period when an egg matures and is released into the fallopian tubes. This is â€Å"due to the stimulation of leutenizing hormone (LH), which then stimulates the remaining follicle cells to turn into a corpus luteum which then secretes progesterone to prepare the uterus for possible implantation. If an egg is not fertilized and does not implant, the corpus luteum disintegrates and when it stops producing progesterone, the lining of the uterus breaks down and is shed.† (biology.clc.uc.ed, 2007) Uterus   Ã‚  Ã‚   The uterus is located in the female abdominal cavity. It is lined with millions of cilia. These are tiny follicles that both attach the egg to the wall of the uterus and sweep the lining out when the egg disintegrates. At the end of the uterus is the cervix. The cervix has thick walls and a tiny opening leading into the vaginal canal. The cervix will open to pass the baby through when it is time for it to be born. Vaginal Canal   Ã‚  Ã‚  Ã‚   The vaginal canal extends from the cervix to the outside opening of the female vagina. It allows the penis to be inserted to fertilize the egg, pass menstrual blood out of the body and allow a baby to pass from the body. The walls are highly elastic and will stretch to accommodate the baby’s head. The Vagina   Ã‚  Ã‚  Ã‚   The vagina is the outer area of the female reproductive system. It contains the opening leading to the vaginal canal and a tiny opening located right above it. This is the urethra and it allows urine to pass from the body. Directly above the urethra is the clitoris. This is the female counterpart to the male penis and is also highly sensitive. Covering the openings is the vulva. This consists of inner and outer labia, which are folds of skin. The vulva becomes covered with body hair when the female matures. Fertilization   Ã‚  Ã‚  Ã‚   Fertilization of the egg occurs when the sperm meet the egg at the far end of the fallopian tube. The sperm fertilize the egg, the egg implants itself into the lining of the uterus and a new human is created. The female reproductive system  Ã‚  Ã‚  Ã‚   http://emc.maricopa.edu/faculty/farabee/biobk/BioBookREPROD.html References http://emc.maricopa.edu/faculty/farabee/biobk/BioBookREPROD.html http://biology.clc.uc.edu/courses/bio105/reproduc.htm http://www.kidshealth.org/parent/general/body_basics/female_reproductive_system.html