B5g: Life goes on Flashcards
Describe the hormones in the menstrual cycle(3+3+3+3)
Oestrogen
- produced in ovaries
- causes lining of uterus to repair (thicken + grow)
- stimulates production of LH and inhibits production of FSH
Progesterone
- produced in ovaries
- maintains the lining of the uterus; when level of progesterone falls, lining breaks down
- inhibits production of LH
FSH (folliclestimulating hormone)
- produced in pituitary gland
- causes egg to develop in one of the ovaries
- stimulates ovaries to produce oestrogen
LH (luteinising hormone)
- produced by pituitary gland
- stimulates release of egg at day 14 (ovulation)
- indirectly stimulates progesterone production
Where is the pituitary gland
in the brain
What affect hormone production in the menstrual cycle and how? (1+2)
negative feedback mechanisms
if concentration of one hormone too high, release of another hormone will reduce it to lower level
e.g. FSH/LH (indirectly) stimulates ovary to release oestrogen/progesterone, which inhibits release of FSH/LH
Name some treatments for infertility (6)
artificial insemination
use of FSH
“in vitro” fertilisation (IVF)
egg donation
surrogacy
ovary transplants
Describe artificial insemination and when is it used(2)
if male sperm count low, problem w/ sperm reaching egg or if single woman/lesbian couple
sperm donated from another male and inserted into woman’s vagina w/o sex
Describe egg donation and when is it used(2)
if woman cannot make eggs
another woman may donate some of her eggs to her, especially if undergoing IVF (“spare eggs”)
Describe surrogacy and when is it used(2)
if uterus has been removed or if hostile environment (leading to miscarriage)
embryo (from IVF) implanted into uterus of another woman (surrogate mother), who gives birth to the baby
Describe ovary transplants and when is it used(2)
if woman has no ovaries or ovaries damaged/produce no eggs (due to surgery/radiation treatment for ovarian cancer)
healthy ovary donated by another woman transplanted to restore fertility
Describe IVF and when is it used(6)
if eggs are not released from ovaries or fallopian tubes blocked; can’t become pregnant naturally
woman’s eggs fertilised outside body
FSH injected, stimulates ovaries to produce eggs
eggs collected from woman, mixed w/ man’s sperm in glass dish
1 healthy sperm injected into each egg, fertilised eggs begin to develop into embryos
when they are tiny balls of cells, few chosen inserted into woman’s uterus
Describe use of FSH and when is it used(2)
if woman has low levels of FSH, eggs don’t develop properly, so can’t get pregnant
FSH injected to stimulate eff production by ovaries, fertilisation +likely, +fertility
Benefits of infertility treatments (1)
can give infertile couples child, stress/sadness to people who want a family
Risks of infertility treatments (3)
IVF +chance of multiple pregnancies (twins), danger to mum’s health and financial burden
expensive, no guarantee to work
ovary transplant risk of rejection
Moral issues of infertility treatments (2)
in IVF, not all the fertilised eggs are implanted back into woman; throwing them away = denying life, morally wrong
unnatural, playing God
Why and how is foetal development checked? (3)
to identify genetic disorders (Down’s syndrome/cystic fibrosis) before birth
amniocentesis - long needle inserted into uterus to remove some amniotic fluid containing foetal cells
cells grown in lab, divide, chromosomes observed under microscope and counted - chromosomal analysis
Ethical issues raised by foetal screening (2)
if foetus has genetic disorder, parents may consider to abort pregnancy => disabled are undervalued in society
amniocentesis increases risk of miscarriage and may result in the abortion of a healthy foetus
