Puberty And The Menstrual Cycle Flashcards
What is the menstrual cycle
- a woman’s monthly release of an egg from her ovaries
What hormones are released during puberty and what do they cause
- Sex hormones; to trigger secondary sexual characteristics (facial hair, breast growth)
Describe the 4 stages of the menstrual cycle
1) [day 1] menstruation starts: the uterus lining breaks down for about 4 days
2) Uterus lining builds up again, [day 4-14], the thick spongy layer full of blood vessels are ready to receive a fertilised egg
3) [day 14] An egg develops and is released, this is called ovulation
4) [day 14-28] The wall is maintained for this time. If egg isn’t fertilised on the uterus wall, the spongy lining breaks down and the whole cycle starts again
Which 4 hormones control the menstrual cycle
- FSH (follicle-stimulating Hormone)
- Oestrogen
- LH (luteinising Hormone)
- Progesterone
What is going on in the menstrual cycle diagram
- High amounts of FSH on day one (it makes egg grow). It is produced by pituitary gland in the brain. It stimulates production of Oestrogen
- Oestrogen is produced in ovaries, causing lining of uterus to grow. Stimulates production LH and inhibits FSH
- LH is produced by the pituitary gland, stimulates ovulation on day 14
- Progesterone is produced in the ovaries by the remains of the follicle after ovulation. It maintains lining in 2nd half of cycle. When levels of progesterone falls, the lining breaks down. Inhibits LH and FSH
What do Oral contraceptives do
- Contains progesterone and oestrogen that stops egg from releasing
- ADV: 99% effective, no ovulation, can protect you from certain cancers
- DADV: relies on taking it everyday, doesn’t prevent STI, bloods clot and breast cancer risks
What do spermicides do
- Release chemicals to kill sperm so that the egg doesn’t get fertilised
- ADV: it is readily available
- DADV: Not very effective
What do condoms do
- Acts as a barrier to stop sperm reaching egg
- ADV: prevents STD
- DADV: could tear and sperm could get through
What do diaphragms do
- fix over cervix so sperm can’t get through
- ADV: 92-96% effective
- DADV: Must be right size and doesn’t protect you from a STD
What does a intrauterine device do
- copper device inserted into uterus that prevents egg implanting in lining of uterus, and slowly releases progesterone and killing sperm
- ADV: can be removed easily if you change your mind
- DADV: doesn’t protect against STD
What does abstinence do
- no sex, no fertilisation
- ADV: no side effects, easy if you change your mind
- DADV: you might get your ovulation days wrong
What do surgical methods do for contraception
- men: sperm ducts are cut, vasectomy, prevents sperm in semen
- women: Oviducts cut/tied to stop egg reaching uterus
- ADV: 99% effective
- DADV: doesn’t stop STI, permanent, surgery is risky
What are different reasons for infertility
- Eating disorders
- obesity
- lack of important female hormones
- Damaged oviducts
- lack of sperm in semen
- Older ages are harder
How to treat infertility
- If a women cannot get pregnant due to lack of FSH, artificial FSH can be used as a fertility drug
- This means her eggs can mature, and with artificial LH can be stimulated to be released
- This makes it naturally possible to get pregnant
IVF
In vitro fertilisation
Describe the steps in IVF
- FSH injected for eggs to mature, LH injected to cause ovulation
- several eggs mature and are released
- eggs are harvested
- sperm from males is added to the eggs in a Petri dish, fertilisation occurs
- healthy embryos are selected, spare embryos can be stored/used for research
- 2-3 embryos implanted into female uterus
- The embryo develops normally and baby is born
ADV of IVF
- you can have a baby with your genetics
- treatment funded by NHS
- eggs can be collected and stored for a later date
DISADVANTAGE of IVF
- costs society money because it is funded by NHS
- Health risks
- physically and emotionally stressful
- Hugely emotion if there is a miscarriage
- ethical concerns
- at higher risk for premature births, expensive to keep premature babies alive
- high risks for child to have a disability
What hormones are released during puberty and where from
Testosterone (from testes) and oestrogen (from ovaries)
What does testosterone stimulate
Sperm production and facial hair
What does oestrogen stimulate
- breast development
- eggs to mature
Where is FSH (Follicle-Stimulating Hormone) produced, what does it cause and what does it stimulate / inhibit
- produced: Pituitary gland
- Causes: egg to mature in a follicle (in the ovaries)
- Stimulates: the ovaries to produce oestrogen
Where’s oestrogen produced, what does it cause and what does it stimulate / inhibit
- Produced: Ovaries
- Causes: lining of uterus to grow
- Stimulates: release of LH
- Inhibits: FSH
Where’s LH produced, what does it cause and what does it stimulate / inhibit
- produced: pituitary gland
- causes: release of egg at day 14 ovulatiuon
Where’s progesterone produced, what does it cause and what does it stimulate / inhibit
- produced: ovaries by the remains of the follicle after ovulation
- Causes: maintains uterus lining during 2nd half of cycle
- Inhibits: LH and FSH
What happens when progesterone levels fall
The lining breaks down
What’s a contraceptive patch
- contains oestrogen and progesterone
- stuck on skin and lasts 1 week
What is a contraceptive implant
- inserted under skin
- releases continuous amounts of progesterone (stops egg release, making it hard for sperm to reach egg)
- can last 3 yrs
What is a contraceptive injection
- injection containing progesterone
- lasts 2-3 months
What is adrenaline, where is it released, and what does it do
- hormone
- released by adrenal glands (above kidneys)
- released in response to stress/scary situations
- it increases supply of oxygen and glucose to cells in the brain and muscles (+ increasing heart rate)
What is Thyroxine, where is it released, and what does it do
- hormone
- released by thyroid gland in neck
- regulates basal metabolic rate (speed at which chemical reactions occur while body is at rest)
- stimulates protein synthesis, growth and development
- released in response to thyroid stimulating hormone
