B5 (2) Flashcards
what are the 4 main hormones of the menstrual cycle?
- FSH
- Oestrogen
- LH
- Progesterone
what is FSH? where is it released from?
a hormone that matures the egg before leaving the ovary
- released by pituitary gland
what is Oestrogen? where is it secreted from?
a hormone that thickens the uterus lining in preparation for an embryo to implant itself
- secreted by ovaries
what is LH? Where is it secreted from?
when LH levels increase, it stimulates the ovaries to release one egg ( this is known as ovulation)
- secreted by pituitary glads
what is Progesterone? where is it secreted from? where is it secreted from>
a hormone that maintains the uterus lining until it is evident that the egg has not been fertilised
- when this happens progesterone levels drop and the uterus lining breaks down, which starts the menstrual cycle
- secreted by the ovaries
what happens on days 1-7 of the menstrual cycle?
menustration (bleeding) occurs
- high concentrations of FSH cause the egg to mature and FSH stimulate oestrogen release
what happens on days 8-13 of the menstrual cycle?
The uterus lining thickens
- this is controlled by oestrogen –> released by the ovaries because the ovaries have been stimulated by the FSH from days 1-7.
Oestrogen concentrations increase and inhibit FSH. Oestrogen stimulates the uterus lining to thicken and for LH to be released
what happens on days 15 -28 of the menstrual cycle?
The uterus lining is maintained by progesterone and oestrogen increases
what happens from day 22 of the menstrual cycle?
if an egg is not fertilised then oestrogen and progesterone levels decrease
- if the egg IS fertilised then the hormone levels remain high so the uterus lining does not break down
what is ovulation?
when an ovary releases an egg
what does inhibit mean?
stops
what is fertility?
the ability for an individual/couple to conceive
what is infertility?
inability to conceive
what are 4 causes of infertility in males?
- Poor quality semen
- Scarring from surgery on reproductive organs
- Low levels of testosterone
- side effects of other medical treatments
How does poor quality semen cause infertility in males?
- there would be low numbers of sperm within the semen
- low mobility of sperm within semen
how does scarring on reproductive organs cause infertility in males?
could cause a blockage in the sperm duct or in the testes
how does low levels of testosterone cause infertility in males?
testosterone is involved in sperm production within the testes
- and is a reproductive organ in males
how does side effects of other medical treatments cause infertility in males?
E.g cancer - chemotherapy treatment impacts on hormone and sperm quality
what are 4 causes of infertility in females?
- Problems during ovulation
- Scarring from surgery on the reproductive organs
- Endometriosis
- side effects from other medical treatments
How does problems during ovulation cause infertility in females?
FSH and LH levels are low so eggs are not maturing or being released from the ovaries
Hows does scarring from surgery on reproductive organs cause infertility in females? (2)
- leads to inability for embryos to implant in the uterus
- or a blockage —> so egg can’t pass from the ovaries along the oviducts to the uterus
what is endometriosis?
a condition where tissues from the uterus grow in other locations (e.g oviducts, ovaries or bowels)
How does endometriosis cause infertility in females??
leads to complications during pregnancy –> can lead to infertility if embryo can’t implant itself into the uterus lining or if it implants itself in the wrong areas (e.g oviducts)
how does side effects of other medical treatments cause infertility in females?
what do fertility drugs do?
increase the chance of pregnancy
what do most fertility drugs contain? (2)
FSH - matures the eggs within the ovaries before they are ready to be released
LH- stimulates ovulation
what is an advantage of fertility drugs?
gives couples opportunity to have a child
what is a disadvantage of fertility drugs?
multiple pregnancies occurring puts a strain on both mothers and embryos in the uterus as they are competing for proteins
what is IVF
In Vitro Fertilisation
in vitro means - outside of the body/organism
what are the steps for IVF?
- mother is given FSH and LH to stimulate egg maturisation and ovulation
- eggs are collected and fertilised by sperm in a petri dish
- 1 or 2 of the developing embryos are inserted back into the mother’s uterus
what makes IVF ‘in vitro’
the petri dish is outside of the body
what are 3 advantages of IVF?
- allows people to have babies of their own
- embryos can be screened for genetic diseases —> so healthy embryo is inserted in uterus and the ones with genetic diseases are destroyed
- unused eggs can be used for other couples
what are 6 disadvantages of IVF?
- has side effects (e.g mood swings and headaches)
- possibility of multiple pregnancies
- physically and emotionally stressful procedure
- low success rate
- expensive - for both NHS and couple (if done privately)
- ethical issues - excess embryos are destroyed
what are ethical issues of IVF
-couples may want to choose the gender of baby and therefore discard embryos of gender they don’t want
- couples may want to choose the characteristics of their baby
what does hormonal contraception involve?
involves artificial hormones being inserted into the body
- inhibits FHS production by releasing oestrogen and/or progesterone –> this stops the egg maturing
what are 3 hormonal contraceptions?
- Oral contraceptive pills
- contraceptive implant, injection or patch
- hormonal intrauterine device
What do contraceptive pills contain?
contains a combination of oestrogen and progesterone
how does contraceptive implant, injection or patch work?
release oestrogen and progesterone to inhibit FSH release and stops the egg maturing from the ovaries
what are 3 advantages of hormonal contraceptions?
- 99% effective if taken correctly
- free from NHS
- contraceptive implant is long lasting
what are 5 disadvantages of hormonal contraceptions?
- No STI/STD protection
- side effects of modified hormone levels
- oral contraceptive pill: side effects of headaches
- people may forget to take pill
- contraceptive implant, injection, patch: causes spotting, continuous bleeding from the uterus
what are 4 non-hormonal contraceptions?
- copper intrauterine device
- spermicidal agents
- abstaining from sexual intercourse when an egg may be in the oviduct/ during most fertile days of the month [day 14 (ovulation) and day 22]
- surgical method of sterilisation
how does copper intrauterine device work?
prevents embryo implantation
how does spermicidal agents work?
is a gel that kills sperm
how do surgical method of sterilisation work?
prevents sperm or eggs being released during sexual intercourse
- cuts/ blocks tubes that carry sperm out of the penis or that carry the egg from the ovaries to the uterus
what are 3 advantages of non - hormonal contraception?
- easy to buy and use
- 99% effective if used correctly
- offer protection from STIs
what are 6 disadvantages of non - hormonal contraception?
- physical barrier may tear (e.g condom) –> so fertilisation could occur or STIs can be contracted
- people have allergic reactions to spermicidal agents or latex ( makes physical barriers - condoms)
- surgical methods are permanent so can’t be reversed
- mistimings of abstaining from sexual intercourse during fertile days
- spermicidal agents are less effective
- possible infection from surgical methods of sterilisation
what does FSH stand for?
Follicle- stimulating hormone
