The role of the sex organs in fertilization starts with the reproductive organs. First the sperm cells are created within a man's testicles and a woman's egg is matured and produced by her ovary. All of our cells have 46 chromosomes, but sperm and egg cells have 23 each. When they meet and fertilize, you will have combined 46 chromosomes. Each sperm and egg cell carries different genetic info, therefore producing different individuals. Each has their own unique DNA, which is why a person looks different from their siblings, etc. When sperm is deposited into the vagina, it swims to the woman's reproductive tract to the fallopian tubes and awaits the release of her egg. Once the egg is released (ovulation) the sperm cells try to fertilize it and only one succeeds. The fertilized egg then travels down to the uterus and implants into the uterine lining. Once implantation happens, a woman's body produces a hormone known as HCG, implicating she is pregnant.
The function of each of the male and female internal and external sex organs in relation to the sperm and the egg start from the outside, the male has two visible sex organs, the testes and penis. The testes are the primary male sexual organs in that they make sperm and produce testosterone. The sperm cell is the male sex cell gamete. Testosterone is the hormone that causes male secondary sex characteristics such as facial and pubic hair, thickened vocal cords and developed muscles. While in the process the sperm travel from each testis to a coiled tube on the outer surface of each testis called the epididymis, where they mature in about 20 days. The sperm exit the body through the penis.
During sexual intercourse, smooth muscles contract and propel mature sperm from the end portions of the epididymis through a long tube inside the body. From there, the sperm get mixed with nutrient-rich fluids from the seminal vesicles and a milky secretion from the prostate gland. This combination of sperm and fluids is called semen. Once the semen is made, it passes through urethra within the penis, exiting the body through the opening of the penis.
All of the female's sexual organs are located within her body except the vulva. The two ovaries are the major female sex organs, the counterpart of the male testes. The ovaries make the eggs, which are the female gametes, and produce estrogen, the female sex hormone. Estrogen causes female secondary sexual characteristics such as pubic hair, breast development, widening of the pelvis and deposition of body fat in hips and thighs. The ovaries are located in the abdomen. Eggs develop inside the ovary and are released upon ovulation into a tube lined with fingerlike projections. The egg travels through the Fallopian tube, where fertilization can take place, to a muscular chamber called the uterus. The uterus is where the baby develops is made of smooth muscle and is usually about the size and shape of a small pear turned upside down. The cervix leads into a smooth-muscle-walled tube called the vagina, or birth canal.
The vagina connects the uterus to the outside of the body, and its opening is covered by the labia. The vagina receives the male's penis during sexual intercourse and delivers the baby during childbirth.
Once the semen is deposited at the base of the uterus, the sperm begin a long journey to fertilization. The long journey to fertilization must be completed within 12 to 48 hours, before the sperm die. They must first cross the barrier of the cervix, which will be easier completed if the woman has just ovulated. Fewer than 1,000 sperm out of the millions in the semen actually reach the Fallopian tubes.
Many sperm surround the egg in the Fallopian tube. The head of each sperm releases enzymes that begin to break down the outer, jelly-like layer of the egg's membrane, trying to infiltrate the egg. Once a single sperm has penetrated, the cell membrane of the egg changes its electrical characteristics. This electrical signal causes small sacs just beneath the membrane to unload their insides into the space surrounding the egg. The other sperm die within 48 hours. The cortical reaction ensures that only one sperm fertilizes the egg.
Hi. My name is Speedy. I began life as a spermatocyte. I have 46 chromosomes, combined from an X and Y sex genetic material. I was created in male human’s testicles and traveled to his epidiymis, which is just a glorified name for the coiled tube on the outer surface of each testis. When I grew up to my teenage years I split into two and became a spermatid with 23 chromosomes. Now that I am all grown up, 20 days old, I am now sperm. My companions and I are waiting for our voyage to begin. Our mission is to find the glorious egg and break in her outer shell. We all know that she will only be letting one of us will make it in, so I will have to swim hard and fast to succeed.