B5g: Life goes on Flashcards Preview

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Flashcards in B5g: Life goes on Deck (16):
1

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

2

Where is the pituitary gland

in the brain

3

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

4

Name some treatments for infertility (6)

artificial insemination

use of FSH

"in vitro" fertilisation (IVF)

egg donation

surrogacy

ovary transplants

5

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

6

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")

7

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

8

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

9

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

10

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

11

Benefits of infertility treatments (1)

can give infertile couples child, ­stress/sadness to people who want a family

12

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

13

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

14

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

15

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

16

How can fertility in humans be controlled? (2)

by artificial use of sex hormones: contraceptive pill and fertility drugs

contraceptive pill contains oestrogen, if taken every day to keep level permanently high, mimics pregnancy, inhibits FSH release, prevents egg production, development and release of egg (ovulation)