Bonjour!
Assalamualaikum wr wb,
Our summary for todays topic about Hormones in my IGCSE class..
Puberty
Puberty 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.
Changes occur at puberty because of hormones:
testosterone - produced by the testes - controls the development of male secondary sexual characteristics
oestrogen - produced by the ovaries - controls the development of female secondary sexual characteristics
Changes 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
|
The menstrual cycle
The menstrual cycle is a recurring process which takes around 28 days. During the process, the lining of the uterus is prepared for pregnancy. If pregnancy does not happen, the lining is then shed. This is known as menstruation.
Hormones that control the menstrual cycle
- they are involved in controlling the release of an egg each month from an ovary, and changing the thickness of the uterus lining.
Hormone
|
Produced
|
Role
|
FSH
(follicle stimulating hormone)
|
Pituitary
gland
|
Causes
an egg to mature in an ovary. Stimulates the ovaries to release oestrogen
|
Oestrogen
|
Ovaries
|
Stops
FSH being produced (so that only one egg matures in a cycle). Repairs and
thickens the uterus lining. Stimulates the pituitary gland to release LH.
|
LH
(luteinising hormone)
|
Pituitary
gland
|
Triggers
ovulation (the release of a mature egg)
|
Progesterone
|
Ovaries
|
Maintains
the lining of the uterus during the middle part of the menstrual cycle and
during pregnancy.
|
Hormone levels during the menstrual cycle
If a woman becomes pregnant, the placenta produces progesterone. This maintains the lining of the uterus during pregnancy and means that menstruation does not happen.
Credit : BBC bitesize