Reproductive hormones
A Chemical messenger produced in glands and carried by the blood to specific organs in the body. is a chemical substance produced by a An organ or tissue that makes a substance for release, such as a hormone.. Hormones are carried by the blood around the body but alter the activity of specific The organ with receptor molecules on its cell surfaces which recognise a specific hormone. only.
Different hormones affect different organs or cells.
Puberty
Time during which sexual maturity happens. is the stage in life when a child's body develops into an adult's body. The changes take place gradually, usually between the ages of 10 and 16.
During puberty, reproductive hormones cause secondary sex characteristics to develop:
- Male sex hormone produced in the testes, which is responsible for puberty in boys. - produced by the testes - is the main male reproductive hormone and it stimulates sperm production.
- A female sex hormone produced in the ovaries, which is responsible for puberty in girls and the regulation of the menstrual cycle. - produced by the ovaries - is the main female reproductive hormone. At puberty, eggs begin to mature and one is released approximately every 28 days. This is called ovulation.
Changes during puberty
A variety of changes happen to boys and girls during puberty.
| Boys only | Boys and girls | Girls only |
| Voice breaks | Pubic hair grows | Voice deepens gradually |
| Hair grows on face and body | Underarm hair grows | Hips get wider |
| Body becomes more muscular | Sexual organs grow and develop | Breasts develop |
| Testes start to produce sperm cells | Ovaries start to release egg cells - menstruation starts |
| Boys only | Voice breaks |
|---|---|
| Boys and girls | Pubic hair grows |
| Girls only | Voice deepens gradually |
| Boys only | Hair grows on face and body |
|---|---|
| Boys and girls | Underarm hair grows |
| Girls only | Hips get wider |
| Boys only | Body becomes more muscular |
|---|---|
| Boys and girls | Sexual organs grow and develop |
| Girls only | Breasts develop |
| Boys only | Testes start to produce sperm cells |
|---|---|
| Boys and girls | |
| Girls only | Ovaries start to release egg cells - menstruation starts |
Learn more about hormones and the menstrual cycle with Dr Alex Lathbridge.
Listen to the full series on BBC Sounds.
In this podcast, learn the key facts about hormones and the menstrual cycle. Listen to the full series on BBC Sounds.
