The role of hormones

accreditation
The main function of any hormone is to carry chemical messages from one tissue or organ to another tissue or organ in the body. Regarding the sex hormones of the ovaries and their control by higher centres in the brain, this message system is responsible for the reproductive cycle to function in a proper manner and also take the blame for heavy mood swings.

During the reproductive years, ovaries produce oestrogen and progesterone. These two are the major female sex hormones which are controlled by the pituitary gland in the brain. This gland produces a follicle stimulating hormone (FSH) which goes via the bloodstream to the ovaries and causes the follicles (containing the eggs) in the ovaries, to mature and to produce oestrogen.

At the time of ovulation, a luteinising hormone (LH) is secreted, also by the pituitary gland when oestrogen reaches a certain level. The most advanced follicle of one of the ovaries releases an egg which enters the Fallopian tube and is available for fertilisation. The follicle changes by becoming a yellow cyst (corpus luteum), which starts producing progesterone as well as oestrogen.

Oestrogen and progesterone
Oestrogen and progesterone play an important part in building up the endometrium (lining of the uterus), which is prepared every month for a possible pregnancy. If the egg is not fertilised, hormone production declines. When the progesterone drops below a certain level, the endometrium sheds over a few days – this is called menstruation.

As the oestrogen and progesterone levels drop, the production of FSH is set into motion again, thereby starting the whole cycle over again. When women grow older, the eggs in their ovaries diminish, there are less follicles available and hormone levels begin to fluctuate. When this starts happening, it is usually the start of menopause.

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Voting Booth
Gauteng DA leader Solly Msimanga says the party's voters want it to explore conditional coalition talks with the ANC. 
Please select an option Oops! Something went wrong, please try again later.
Results
It's a step in the right direction. An ANC-DA coalition would be the most stable option for SA
33% - 2859 votes
The DA should focus on working with all opposition parties, including the EFF, to unseat the ANC
15% - 1268 votes
The DA should rather remain in opposition than form a coalition with the ANC or the EFF
52% - 4536 votes
Vote
Rand - Dollar
17.09
-0.4%
Rand - Pound
20.66
-0.0%
Rand - Euro
17.80
-0.0%
Rand - Aus dollar
11.54
-0.0%
Rand - Yen
0.12
-0.0%
Gold
1,754.60
0.0%
Silver
21.61
0.0%
Palladium
1,856.61
0.0%
Platinum
984.00
0.0%
Brent Crude
83.63
-2.0%
Top 40
66,754
-0.0%
All Share
73,151
+0.0%
Resource 10
71,441
-0.1%
Industrial 25
87,347
-0.2%
Financial 15
16,370
+0.4%
All JSE data delayed by at least 15 minutes Iress logo
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.

LEARN MORE