Hormones In Human Reproduction Flashcards
Explain how hormones interact in reproduction
- The pituitary gland releases FSH. This stimulates the maturing of an egg in a follicle of the ovaries
- This stimulates the ovaries to secrete oestrogen. Oestrogen causes the uterus lining to grow. It inhibits the secretion of FSH from the pituitary gland and stimulates the secretion of LH
- LH stimulates the release of the mature egg from the follicle (ovulation). Ovulation stimulates the release of progesterone
- Progesterone maintains the thickness of the uterus lining so that the egg can be implanted if it is fertilised. Progesterone inhibits the secretion of FSH and LH, so that no more eggs are matured and released from the ovaries.
- If the egg is not fertilised this decreases levels of rprogesterone, so the uterus lining and egg are released from the uterus and the woman has her period.
- The decrease in progesterone stimulates the secretion of FSH and LH, and the cycle repeats.
What is a disadvantage of oral contraceptives e.g. ‘the pill’?
The pill must be taken everyday- if a woman forgets, this increases the risk of her becoming pregnant
The pill has side effects such as breast cancer and blood clots
The pill does not protect against STI’s e.g HIV
What are the advantages of the oral contraceptive pill?
It can be very effective if taken correctly
What are the disadvantages of using an implant, injection or skin patch?
They have side effects
They do not protect againts STI’s e.g HIV
What are the advantages of using implants, injections or skin patches?
They are long-lasting as opposed to having being taken everyday
What are the disadvantages of using barrier methods e.g. condoms and diaphragm for contraception?
The condom can break or slip off
They aren’t 100% effective in preventing pregnancy
What are the advantages of using barrier methods e.g. condoms or diaphragms?
Highly effective if used properly
Reduce the risk of STI’s e.g. HIV
What are the advantages of using intraterine devices as a use of contraception?
Highly effective
Long lasting
Do not have many side effects
What are the disadvantages of using intrauterine devices?
They don’t protect against STI’s e.g. HIV
Name an intrauterine device
The coil
Name the six methods of contraception
Barrier methods
Intrauterine devices
Oral contraceptives
Progecting (implants,skin patches,inj.)
Abstinence
Sterilisation
What are the disadvantages of abstinence?
It is difficult to detect when a woman has ovulated
They don’t protect againts STI’s e.g. HIV
What is sterilisation?
The surgical methods of contraception
What does sterilisation do in women?
Prevents the egg from leaving the uterus
What does sterilisation do in men
Prevents the sperm from leaving the penis
What are the advantages of sterilisation?
It is highly effective
What are the disadvantages of sterilisation?
It is difficult to reverse so the person has to be very sure that they don’t want to have children
Doesn’t protect against STI’s e.g. HIV
What are the advantages of abstinence?
No side effects
Which hormones are found in the ‘fertility drug’?
FSH and LH
What do the hormones in the fertility drug do to help with infertility?
FSH stimulates eggs in the ovaries to be matured
LH stimulates the ovulation of more eggs than usual- this increases the woman’s chances of becoming pregnant through sexual intercourse
What happens when the fertility drug does not work?
A woman may undergo IVF treatment
Describe the process of IVF treatment
- The hormone FSH is given to the woman. FSH stimulates eggs in the ovaries to become mature in follicles
- The mature eggs are then removed from the follicles and collected.
- Sperm from the father is then injected into the eggs in a lab using modern technology
- Then the fertilised eggs are incubated and they grow into embryos
- Once the embryos are mature, 1-3 of them are transferred and implanted into the woman and can grow in the woman’s uterus like in a normal pregnancy.
What are the advantages of IVF treatment
- The woman can finally have a baby
- The eggs can be stored for later use- this is normally done with cancer patients as it means that they can still have children after their cancer treatment
- The remaining eggs can be used in research
What are the disadvantages of IVF treatment?
- It is physically and mentally draining on the parents
- Expensive
- Can lead to multiple births which is dangerous for the mother and the babies
- Not all embryos are transferred to the woman- they may be destroyed, this is seen as unethical by some people.
Which hormone controls secondary sex characteristics?
Oestrogen
