Hormones are chemical messengers that travel in the blood stream from the place where they are made (called glands) to the place where they do their work. Each hormone has a specific job!

Sex Hormones

An area of the brain known as the hypothalamus activates a hormone called gonadotropin-releasing hormone (GnRH).

GnRH sends a signal to the pituitary gland (a pea-sized gland near the base of the brain) to release hormones that stimulate the ovaries (in girls) or testicles (in boys) to make sex hormones.

This chain reaction and release of hormones brings on the changes of puberty.

The ovaries and testicles produce two sex hormones responsible for changes that occur during puberty.

An area of the brain known as the hypothalamus activates a hormone called gonadotropin-releasing hormone (GnRH).

GnRH sends a signal to the pituitary gland (a pea-sized gland near the base of the brain) to release hormones that stimulate the ovaries (in girls) or testicles (in boys) to make sex hormones.

This chain reaction and release of hormones brings on the changes of puberty.

The ovaries and testicles produce two sex hormones responsible for changes that occur during puberty.

Testosterone

In boys, testosterone is produced by the testes (male sex organs). Testosterone stimulates the development of the penis and testes and causes muscle and pubic hair growth. It's also responsible for lowering the voice.

Women and girls also have testosterone in their body, which is produced in small amounts by the ovaries to help maintain muscle and bone strength.

After puberty you make 200,000 -  400,000 sperm cells a day for the rest of your life

Sperm build up in tubes around the testicles. They travel along some tubes and mix with fluids from glands.

Oestrodiol (oestrogen)

Oestrodiol is the main sex hormone in girls. It's produced by the ovaries and stimulates growth of the breasts and reproductive system, and helps regulate the monthly menstrual cycle.

Boys and men also have oestrodiol in their body. It's produced in small amounts by the brain and testes to help maintain bone density.