3 - REPRODUCTION

yayyy reproduction yayyy

What part of the female reproductive system is 1?

fallopian tube/oviduct

What part of the female reproductive system is 2?

ovary

What part of the female reproductive system is 3?

cervix

What part of the female reproductive system is 4?

vagina

What part of the female reproductive system is 5?

uterus

What does the fallopian tube/oviduct do?

• Carries the egg cell to the uterus

• fertilisation usually takes place in the oviduct

What does the ovary do?

where eggs mature

What does the cervix do?

entrance to the uterus

What does the vagina do?

where sperm are depositied

What does the uterus do?

where a fertilised egg develops into a foetus

What part of the male reproductive system is 1?

glands

What part of the male reproductive system is 2?

penis

What part of the male reproductive system is 3?

scrotum

What part of the male reproductive system is 4?

makes sperm

What part of the male reproductive system is 5?

urethra

What part of the male reproductive system is 6?

sperm duct

What do the glands do?

adds a liquid to sperm

What does the penis do?

carries sperm out of the body (into the vagina)

What does the scrotum do?

holds testis

What do the testis do?

makes sperm

What do the urethra do?

connects the bladder and testis to the penis

What does the sperm duct do?

carries sperm from the testis to the urethra

Wha happens during puberty?

reproductive organs become active

What do reproductive organs do?

they produce sex hormones and gametes

What do reproductive hormones do?

causes secondary sex characteristics to develop

What is the main female reproductive hormone?

oestrogen

Where is oestrogen produced?

in the ovary

What is a major function of oestrogen?

to trigger the development of secondary sexual characteristics in females

What is the main male reproductive hormone?

testosterone

Where is testerone produced?

produced by testes

What is a major function of testosterone?

• stimulating sperm production

• triggers development of secondary sexual characteristics

What are changes that happen to both genders during puberty?

• growth spurt

• brain maturing

• body hair

• external genetalia growth

• skin darkens

What are changes that happen to females during puberty?

• breasts development

• menstration starts

• urerus grows and becomes active

• female pattern of fat deposited on hips, buttocks and thights

What are changes that happen to males during puberty?

• larynx gets bigger and voice breaks

• sperm produced

What hormones involved in the menstrual cycle are secreted by the pituitary gland?

FSH, LH

What hormones involved in the menstrual cycle are secreted by the ovaries?

oestrogen, progestrone

What does the FSH do?

• causes eggs to mature

• stimulates ovaries to produce ovaries

What does LH do?

causes egg to be released from the ovary

What does oestrogen do?

• stimulates growth of uterus lining

• stops FSH being produced to ensure that only one egg matures in a cycle

• stimulates the pituatary gland to release LH

What does progestrone do?

• inhibits both FSH and LH production to keep the body ready for pregnancy until it is clear the egg is not fertilised

• maintains uterus lining during middle part of menstrual cucle and during pregnancy

What are contraceptive methods?

prevents eggs and sperm meeting or prevents a fertilised egg from implanting in the uterus wall

What are the different kinds of contraception?

• hormone based contraceptives

• chemical methods

• barrier methods

• abstinence

• surgical method

What are different kinds of hormone based contraceptives?

• oral contraceptives (eg. contraceptive pill)

• contraceptive implant

• contraceptive injections

• contraceptive patch

How do oral contraceptives work?

• they contain low dosages of estrogen and progesterone which inhibits FSH which prevents the egg from maturing

• it also stops the uterus lining from developing chich prevents implantation of a fertilised egg

• it also makes the mucus in the cervix thich to provent sperm entering

What is different about some contraceptive pills?

they contain only progesterone

What is the benefit of a progesterone only pill?

it has fewer side effects from the mixed pill

Why does the progestrone only pill need to be taken regularly?

if you forget progesterone levels decrease which causes FSH/LH to increase as they are no longer inhibited, which causes the egg to mature and be released

What are the advantages of oral only contraceptives?

they are effective and easily reversible

What is a contraceptive implant?

a tiny tube inserted under the skin that slowly releases progesterone to prevent an egg maturing

What are the advantages of a contraceptive implant?

it lasts up to 3 years and is 99.5% effective (because the hormone level in the blood is more constant)

What are the disadvantages of contraceptive implants?

may be bruising/tenderness/swelling at first and can be difficult to remove

What are contraceptive injections?

injections that slowly release progesterone

What are the advantages of progesterone?

99% effective

What are the disadvantages of contraceptive injections?

they only last 12 weeks

What is a contraceptive patch?

a patch that contains estrogen and progestrone and prevents egg maturing/being released

How are the hormones absorbed in a contraceptive patch?

they are absorbed directly into the blood

What are the advantages of contraceptive patches?

they are more than 99% effective and may prevent against ovarian/uterus/colon cancer

What is the main kind of chemical method?

spermicides

What do spermicides do?

kill or disable sperm

What are the disadvantages of spermicides?

they’re not very effective on their own

How are spermicides often used?

with barrier methods

What are different kinds of barrier methods?

• condoms

• diaphragm/cap

• intrauterine devices (IUD)

What do barrier methods do?

they prevent the sperm from reaching the egg

What do condoms do?

collects sperm and prevents them reaching the egg

What are the advantages of condoms?

• no side effects

• protection against some sexually transmitted infections

What are disadvantages of condoms?

easily damaged

What do diaphragm/caps do?

placed over cervix before sex to prevent spern entry

What are the advantages of a diaphragm/cap?

no side effects

What are the disadvantages of a diaphragm/cap?

needs to be fitted initially by a doctor, needs to be positioned correctly

What does is an IUD?

small structures inserted into the uterus by a doctor

What are the two types of IUD?

copper and progesterone

How do copper IUDs work?

they prevent early embryos from implanting in the uterus wall and thickens mucus around the cervix to prevent sperm from entering

What are the ethical problems with copper IUDs?

involves death of a fertilised egg

How do progestrone IUDs work?

• they prevent ovulation

• they prevent the uterus wall from thickening

• thickens mucus around cervix (prevents sperm entering)

What are the advantages of an IUD?

effective, lasts 3-5 years

What are the disadvantages of an IUD?

very painful to insert

What is abstinence?

not having sexual intercourse specifically around ovulation (rhythm method)

What are the disadvantages of abstinence?

unreliable

What is the main kind of surgical method?

vasectomy

What is a vasectomy for males?

sperm ducts can be cut and tied

What is a vasectomy for females?

oviducts can be cut or tied

What does a vasectomy do?

prevents sperm from getting into semen

What are the advantages of a vasectomy?

effective and usually permanent

Can a vasectomy be reversed?

yes, but its difficult

What are the disadvantages of a vasectomy?

surgery has slight risk of infection, difficult to reverse operation

What are some causes of infertility?

• lack of female hormones

• damage to oviducts

• lack of sperm in semen

• increasing age

• obesity

• eating disorders

What are fertility drugs?

drugs that contain a mixture of FSH and LH taken over a series of days

What does IVF stand for?

in vitro fertilisation

How does IVF work?

• Mother given FSH and LH to stimulate several eggs to mature

• Eggs collected from the mother’s ovaries

• The eggs are then fertilised with sperm outside the body in the laboratory

• Fertilised eggs will divide by mitosis and develop into embryos

• 1 or 2 embryos are inserted back into the mother’s uterus

When is IVF used?

• If the oviduct is damaged or blocked by infection

• The donor egg has to be used

• Very few sperm produced

• No obvious cause of infertility

What are the disadvantages of IVF?

• emotionally and physically stressful

• chance of multiple births

• success rates are not high (under 30%)

• expensive for society and individuals (available free on NHS)

• ethical issues

What are the dangers of multiple births?

• often result in babies born prematurely or with lower birth rates than normal

• increased chance of miscarriages

• possible harm to mother and babies

What are the ethical issues of IVF?

discarded embryos