QUESTIONS-QUESTIONS-QUESTIONS+Year+9

Josephine asked about the nitty gritty of how birth control pills actually act on the body to prevent pregnancy - here is a more comprehensive answer than what I provided today. The birth control pill (also called "the Pill" and the 'Oral Contraceptive Pill) is a daily pill that contains hormones to change the way the body works and prevent pregnancy. As you know from your last Science unit, hormones are chemical substances that control the functioning of the body's organs. In this case, the hormones in the Pill control the ovaries and the uterus. The hormones progesterone and oestrogen are required to be at specific levels for the lining to be suitable for implantation and sustain pregnancy. How do they work?  A woman cannot get pregnant if she doesn't ovulate because there is no egg to be fertilised. Research has shown that NEITHER the progesterone-only pill nor the combine progesterone-oestrogen formulations will always stop ovulation. The combination of these results are a very effective way (but not a 100% effective method) of preventing pregnancy.
 * Part of your class work and home work is to explore the different contraceptives available. You are required to summarise how they prevent pregnancy and also some advantages and disadvantages associated with each type.
 * Most birth control pills are "combination pills" containing a combination of the hormones oestrogen and progesterone to prevent ovulation (the release of an egg during the monthly cycle).
 * The Pill also works by thickening the mucus around the cervix, which makes it difficult for sperm to enter the uterus and reach any eggs that may have been released.
 * The hormones in the Pill can also sometimes affect the lining of the uterus, making it difficult for an egg to attach to the wall of the uterus. Under the influence of the chemicals in the pill, the endometrium (lining of the uterus) doesn't grow to the proper thickness. Periods are often lighter when the pill is being taken. This is because the lining of the uterus has not developed properly. This change also means that the womb is not in the right stage of development to allow a fertilised egg to attach properly (this attachment process is know as implantation).
 * Finally, the pill causes changes to the movement of the fallopian tubes. This effect may reduce the possibility of the ovum being fertilised.

MORE INFORMATION: It was discovered relatively long ago (1930's) that injections of progesterone were effective as a contraceptive in preventing pregnancies. The synthesis of similar but slightly different steroids as mimics to the natural steroids led to the development of the "pill". The "pill" is an oral contraceptive containing synthetic derivatives of the female sex hormones, progesterone and oestrogen. These synthetic hormones prevent ovulation and thus prevent pregnancy. The two synthetic hormones in the "pill" deceive the body into thinking it is pregnant. A high level of progesterone is maintained which inhibits secretions of FSH and LH. The result is that no new egg follicles are developed and no ovulation occurs.


 * Siobhan in 9.4 asked a fantastic question in our 'Crimson Wave' class about Period Pain. What causes it exactly?

My only thoughts were around the contraction of the uterus - I suspected that there was more to the story.

I found some information on a reliable website (we cannot trust everything we read!)

Here is a better answer that I could not provide this afternoon.

When you have your period, tiny molecules called prostaglandins are released by your body to help the muscle of the uterus contract. These contractions occur allowing the uterus to expel its lining (endometrium). This happens as the endometrium would only be needed if an egg was fertilised. The strength of the contractions depends on the amount of prostaglandins your body produces. If your body produces a lot of these molecules, or if you are particularly sensitive to them, you will feel pain.

There is a combination of factors that assist this journey. The combination of muscular contractions within the tube and cilia on the cells within the fallopian tube gradually 'beat' the egg to where it needs to be.
 * Ngoc, also in 9.4, asked about how the fertilised egg (zygote) manages to travel from the oviduct (aka fallopian tube- where fertilisation occurs) to the uterus (where embedding - conception occurs).

=Feel free to add questions to the discussion tab of this page if you have any other areas that you would like to learn more about.=