B5 (2) menstrual cycle and puberty

what is puberty?

period in which the adolescents start to develop secondary sexual characteristics

what are the reproductive hormones for males?

testosterone i(which is produced in testes) stimulates sperm and production

in women?

oestrogen produced by the ovaries

where do eggs go after ovulation?

they are transported along one of the fallopian tubes over to the uterus wha

what would happen if the egg was fertilized?

it would implant into the uterus lining otherwise it would break down and pass out

what is the average length of a menstrual cycle?

28 days

what is stage 1 of the menstrual cycle?

menstruation- the period of bleeding is due to the breakdown of the uterus lining

what is stage 2 of the menstrual cycle?

uterus lining starts to build up again- becomes a thick spongy layer with lots of blood vessels in it lasts around 10days (prepares the uterus lining for fertilised egg)

what is stage 3 callled?

ovulation, takes place in a single day, involves the egg being released from one of the ovaries (up to day 28) maintains the lining of the uterus

what would happen if no fertilised egg made it to the uterus at the end of the cycle?

the extra uterus lining would start to break down

at would happen if there was a fertilised egg?

it would implant into the uterus lining and slowly develop into a foetuswhat

what does oestrogen in stage 2?

stimulate the uterus lining to grow

what does progesterone do? where does it increase the most?

maintains the lining of the uterus, stage 4

where are LH and FSH produced?

in the pituitary gland (small gland near the brain)

what does FSH?

stimulates one of the eggs to mature in one of the ovaries

what does LH do?

stimulates the release of that egg in ovulation

what does FSH stimulate the ovaries to produce?

oestrogen

what happens as oestrogen levels start to increase

they start to inhibit FSH (example of negative feedback)

what happens when oestrogen levels get high?

they stimulate the release of LH which causes this LH spike and results in ovulationwh

at does progesterone also inhibit?

LH and FSH

what are some secondary sexual characteristics that take place?

increase in height, more muscle mass, deepening voice, breast development

what is contraception?

any artificial method people use to prevent pregnancy

what do the hormonal methoids of contraception rely on?

the release of oestrogen, progesterone or the combination of the two

what happens if oestrogen is released steadily everyday?

inhibits the production of FSH (which stimulates egg development) meaning no egg would be developed/released

what does progesterone stimulate the production of?

thick mucus in the cervix so prevents the sperm from reaching the eggwhat d

what does the combined oral contraception pill contain?

a combination of both oestrogen and progesterone how

how effective is it at preventing pregnancy?

over 99% as klong as they’re taken properlywh

at side effects can they have?

headaches, nausea wh

where do you place the contraceptive patch

on the upper arm which slowly releases oestrogen and progesterone

how long does it last?

each patch lasts 1 week

what is the contraceptive injection?

injection of progesterone into the upper armh

how long does each dose last?

2-3 months

what is the contraceptive implant?>

involves a small device being placed under the skin of the arm which will slowly release progesterone

for how long?

upto 3 years

where do you place the intrauterine device (IUD)?

placed inside the uterus wh

at does the plastic version release?

progesterone (stimulate the production of a thick mucus in the cervix) w

hat does the copper version of IUD (copper coil) not involve?

any hormones it just prevents sperm from surviving in the uterus by killing them

how long can both the copper and plastic IUD last for?

over 3 years

whaty do the non-hormonal methods of contraception all have in common

prevent the sperm from meeting the egg

what are condoms worn over?

the penis which traps any sperm

here are female condoms worn?

inside the vagina and trap the spermwha

what are condoms the only form of contraception to do?

they also protect against sexually transmitted diseases

what is the diaphragm?

a shallow plastic tub that fits over the cervix to block sperm from entering the uteruswh

at is a downside of the diaphragm?

not as reliable and has to be used with spermicide (substance that kills sperm)

what can spermicides also be used as alone

, as a form of contraception but they only work around 7/10 times

what is sterilisation? what happens a sa result

cutting/tying the fallopian tubes, if they’re cut eggs won’t be able to travel; from the ovaries to the uterus

when is it generally chosen, why

once a woman has all the kids she wants so is permanent

how can men undergo sterilisation?

by having their sperm ducts cut and tied

how are natural methods of contraception used instead?

only having sex at certain times of the month or stopping sex just before ejaculation

what is the problem of both of these?

very unreliable and not recommended w

hat is the only way to be 100% sure you won’t be pregnant?

by abstaining from sex all together

(IVF) what can we do to increase a women’s low level of fsh

we can give FSH in the form of a pill to help eggs to mature and then give LH to stimulate ovulation

do these work most iof the time?

yes , the woman’s fertility is restored

what happens if these don’t work?

a woman may choose IVF (in vitro fertilisation) in vitro= outside the body

what is the first stage of IVF

women are given FSH and LH to stimulate some of their eggs to mature

stage 2?

eggs are collected from the woman’s ovaries and sperm is also collected from the male

what happens if the man has a low sperm count

docs could use a technique called intracytoplasmic sperm injection

how does ICSI work?

the sperm is injected into the egg cell with a tiny needle

stage 3?

eggs are then fertilised by the sperm

stage 4?

fertilised eggs are then left to grow into embryos in a labratory incubator

why are embryos kept in an incubator whilst in the labratory

to provide the optimum temp for enzymes and thus cell growth

stage 5?

once the embryos are large enough they are transferred into the women’s uterus

what are the pros of IVF

can allow infertile couples to have kidswhat

what is a con of IVF

it doesn’t always work (in the UK the chance of success is 1 in 4)

what is another con of IVF

can be stressful, emotionally upsetting and physically unpleasant

what is an example of this?

a lot of women get abdominal pain and vomiting

what is anotyher downside of putting multiple embryos into the uterus in hope of at least one of them developing?

often leads to multiple births, ie. twins/triplets

what does this give a bhigher risk of? examples?

complications as it’s natural and multiple births , miscarriage and still-birth

why are some people against IVF in general?

often results in unused embryos that are eventually destroyed with having the potential of human life

what have the recent advances in microscope tech done to IVF

not only involved the success rate but also allowed us to remove single cells from the embryos what

what can we use this to do?

genetic tests on the cells and see if they have any diseases

what can we also use this to find out

chjaracteristics of trhe future baby, gender or eye colour

what can this lead to?

designer babies downside as parents can select embryos with certain traits ADRENALINE AND

why does thisd not happen now?

it’s illegal in the uk and in most countries

ADRENALINE AND THYROXINE-