Sperm

So we know about the male reproductive organ and how a sperm is created, so how does it reach the female? Well, firstly, let us look at how the sperm looks like.

So let's begin, the main function of the sperm is to carry the 18,000 male genes to the female’s egg. These genes represent the male's contribution to the DNA make-up of the hoped-for baby. The sperms that have been stored will be ejaculated through semen through the penis and into the vulva when the male is having sex. Then sperms compete to be the first that reaches the egg, so how do they reach it?
They reach it through features in their structure, namely the acrosome, the energy source and the tail. The acrosome also has a surface feature in its membrane which allows it to burrow through the shell of the woman's egg. Using the enzymes that are built into its surface, the sperm cell digests its way through the outer eggshell called the zona pellucida. The sperm cell is then able to enter into the main part of the egg, the ooplasm, achieving successful fertilization.
The second component of the sperm cell is the energy source, its sole purpose is to convert nutrients into energy. Without this, the propulsion system would not have the energy to take the cell up the female genital track.
The third and final component of the sperm cell is the propulsion system. It is the whip-like structure of the sperm tail. It serves the important function of propelling the sperm cell forward with a snake-like motion. It is critical that sperm move forward and not laterally or in circles. The failure of sperm to move forward is described as an abnormality of sperm motility.
I thank www.proceptin.com/phc/sperm-cell.php for the information

Sperm production

This is a video on the production of sperms. The process is known as Spermatogenesis. Spermatogenesis is the process by which male gametogonia develop into mature spermatozoa, the mature male gametes, in many sexually reproducing organisms. In mammals it occurs in the male testes and epididymis in a stepwise fashion, and for humans takes approximately 64 days. Spermatogenesis starts at puberty and usually continues uninterrupted until death, although a slight decrease can be discerned in the quantity of produced sperm with increase in age. The entire process can be broken up into several distinct stages, each corresponding to a particular type of cell. These stages include mitosis (which divides germ cells into spermatocytes), meiosis (which divides spermatocytes into spermatids), spermiogenesis (which matures the spermatids) before being released from the protective Sertoli cells into the lumen of the seminiferous tubule where they are stored.

However, science has brought man far and now there are aritificial sperms being created. In 2006, scientists have fertilised mouse eggs with sperm grown from embryonic stem (ES) cells to produce seven pups, proving that working sperms can be made in the laboratory. This means that in the future, infertile men can also have children as their sperms can be artificially created

start of biojournal

Ok, I think it is time I started on this 20% of my marks. Right, to make this experience fun and interesting, I think I will choose two rather interesting topics - sexual reproduction and issues on sex. Also, as I was not there during the briefing of the journal guidelines, I hope you excuse me should I write off-topic.

First, let us dwelve into the rough definition of sexual reproduction. According to http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/Sexual_Reproduction.html, it is the formation of a new individual (animal or plant) following the union of two gametes. These two gametes differ in structure and are contributed by both parents. Ultimately, these two gametes need to unite and to have nutrients to develop. In humans, the gametes are the sperm and the egg.
Without further a do, let's start on my first question dealing with how reproduction in humans actually occurs. To do this, we must first discover the main anatomy of the male reproductive system.

The two testicles are organs that produce and store millions of sperms. The testicles also produce hormones, like testosterone, which is the hormone that causes guys to develop deeper voices, bigger muscles, and body and facial hair, and it stimulates the production of sperm.

The epididymis and the vas deferens, which make up the duct system of the male reproductive organs. The vas deferens is a muscular tube that passes upward alongside the testicles and transports the sperm-containing fluid called semen. The epididymis is a set of coiled tubes that connects to the vas deferens.

The scrotum. is a pouch-like structure outside the pelvis which contains the testicles This bag of skin helps to regulate the temperature of testicles through contraction and expansion, which need to be kept cooler than body temperature to produce sperm. During puberty, pubic hair grows on the scrotum

The accessory glands, including the seminal vesicles and the prostate gland, provide fluids that lubricate the duct system and nourish the sperm. The seminal vesicles are sac-like structures attached to the vas deferens to the side of the bladder. The prostate gland, which produces some of the parts of semen, surrounds the ejaculatory ducts at the base of the urethra, just below the bladder. The urethra is the channel that carries the semen and urine to the outside of the body through the penis.

The penis is 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. At the end of the glans is a small opening, which is where semen and urine exit the body. The inside of the penis is made of a spongy tissue that can expand and contract.

Having roughly explained the purpoes of every part of the organ, I'll move on to deal with how semen is created and its purpose in reproduction in my next post. I would like to acknowledge http://kidshealth.org/teen/sexual_health/changing_body/male_repro.html for their information and http://static.howstuffworks.com/gif/male-reproductive-system-1.jpg.