B3.2 The Menstrual Cycle

Question 1

describe the menstrual cycle

Answer 1

lasts 28 days where the woman’s body gets ready for pregnancy
lining of the uterus thickens ready to receive fertilised egg
egg matures in the ovum and after 14 days is released into the uterus
if no fertilisation - uterus lining and egg are bled out (period)
if fertilisation occurs - egg is implanted into uterus to receive nutrients

Question 2

hormones involved

Answer 2

FSH(follicle stimulating hormone) - produced by pituitary gland
oestrogen - produced by ovary
LH(lutenising hormone) - pituitary gland
Progesterone

Question 3

roles of the hormones

Answer 3

FSH - causes egg to mature ; stimulates ovaries to produce oestrogen
Oestrogen - builds up uterus lining; inhibits FSH to prevent more than 1 egg; stimulates pituitary to produce LH
LH - at peak levels, ovulation occurs
Progesterone - maintains uterus lining; inhibits LH; at constant high during pregnancy

Question 4

different types of contraception

Answer 4

non hormonal

hormonal

Question 5

non hormonal contraception

Answer 5

condoms(m/f)
cervical cap/diaphragm
intrauterine device (IUD) - copper that kills sperm and prevents implantation of fertilised egg (lasts 5-10 years)

Question 6

oestrogen and progesterone pill (combined)

Answer 6

prevents ovulation
thickens cervix to stop sperm
prevents implantation of fertilised egg
take daily for 21 days of menstrual cycle

Question 7

progesterone pill

Answer 7

thickens cervix mucus to stop sperm
thins lining of uterus to prevent implantation
must be taken same time every day

Question 8

intrauterine system (IUS)

Answer 8

inserted in uterus
thickens cervix mucus to stop sperm
thins lining of uterus to prevent implantation
lasts for 3-5 years

Question 9

causes of infertility

Answer 9

blocked sperm ducts
not enough sperm produced in testes
lack of mature eggs produced
failure of ovaries to release an egg

Question 10

FSH to increase fertility

Answer 10

FSH is given to stimulate ovaries to mature the eggs and trigger oestrogen production too.

Question 11

IVF (in vitro fertilisation)

Answer 11

collecting egg and sperm and fertilising it outside the body
positives - allows new life
negatives - morals?