4- The male reproductive system.

4.1. The male reproductive organs

Most male reproductive organs are located on the outside of the body.

The male reproductive system produces and transports sperm cells. A sperm cell has an oval shape and a tail. The tail allows it to move up the female’s fallopian tubes and fertilise the ovum. Men produce millions of sperm every day.

1)The testicles produce and store sperm.

2)The vasa deferentia are two tubes that connect the testicles to the seminal vesicles. Sperm travels through them.

3) The seminal vesicles produce a liquid that forms part of semen.

4)The prostate produces a liquid that also forms part of semen. Semen carries the sperm and gives it nutrients.

5)The penis contains the urethra. The sperm travels through the urethra to the outside of the body. The urethra also expels urine.

     

4.2. The Puberty in boys.

When boys reach puberty, the brain secretes hormones which activate the testicles to produce testosterone. This hormone brings about many physical changes: pubic hair begins to grow, boys become taller and heavier, the voice deepens, and hair starts to grow under the arms and on the face, the skin develop acne...