Answers
What are the advantages and disadvantages of a kidney transplant over dialysis? -
answer Kidney transplants are a cure, but they can be rejected. Patients are treated
with immunosuppressants. People are not always on the donor list, relatives have to
agree to the donation. Transplants are cheaper than dialysis to the NHS. Long waiting
lists for transplants. Patients have to spend 3-4 hours a day, 3 x a week which can have
a negative impact on their quality of life.
What are the four stages of the menstrual cycle? - answer 1) Menstruation-the uterus
lining breaks down
2) The uterus lining builds up again
3) Ovulation-Around day 14 a egg is released from an ovary.
4) The wall is maintained for about 14 days until day 28. If the egg has not been
fertilised and implanted into the uterus lining it breaks down.
What is the role of FSH (Follicle stimulating hormone) in the menstrual cycle? - answer
Made in the pituitary gland.
Causes a egg to mature in one of the ovaries in a structure called a follicle.
Stimulates the ovaries to produce oestrogen.
What is the role of oestrogen in the menstrual cycle? - answer Produced by the ovaries.
Causes the lining of the uterus to grow. Stimulates the release of LH (which causes
ovulation) and inhibits the release of FSH.
What is the role of LH (Luteinising hormone) in the menstrual cycle? - answer Produced
in the pituitary gland.
Stimulates the release of an egg (ovulation) at day 14.
What is the role of progesterone in the menstrual cycle? - answer Produced by the
ovary by the remains of the follicle. Maintains the lining of the uterus. When the level of
progesterone falls the lining of the uterus breaks down. Inhibits the release of LH and
FSH.
Where is testosterone produced? - answer In the testes.
,How does the contraception pill work? - answer Contains oestrogen and progesterone.
Taking oestrogen every day prevents the release of an egg by inhibiting FSH.
Progesterone reduces fertility by stimulating the production of thick sticky mucus at the
cervix preventing the sperm getting to the egg.
What are the side effects of the pill? - answer Headaches and nausea. Still contract
STIs.
What is the contraceptive patch? - answer Contains same hormones as the pill. Patch is
stuck under the skin (5cm x 5cm). Each patch lasts a week.
What is the contraceptive implant/injection? - answer Implant is inserted under the skin.
Releases progesterone. Can last for 3 years. Injection lasts less time 2-3 months.
What is an intrauterine device? - answer Is a T shaped device that is inserted into the
uterus to kill sperm and prevent implantation of the fertilised egg.
Name three barrier methods, non hormonal methods of contraception. - answer Male
and female condom, diaphragm, spermicide
What is the diaphragm? - answer A plastic cup that fits over the cervix (opening to the
womb) to form a barrier.
How does spermicide work? - answer It kills or disables the sperm.
Name a permanent ways to avoid pregnancy. - answer Abstinence (not having sex),
sterilisation which is having Fallopian tubes or sperm duct cut.
How does IVF work to help infertile couples? - answer FSH and LH are given to a
woman to help eggs mature and release. Eggs are then collected from a woman's
ovaries. The eggs are fertilised in a lab with the man's sperm. The fertilised eggs are
grown into embryos in an incubator. The 1-2 embryos are then transferred to the
woman's uterus to increase chance of pregancy.
What are the pros and cons of IVF? - answer PRO: Gives an infertile couple a child.
CON: Multiple births, these are risky, more chance of still birth and miscarriage.
CON: Success rate is low
CON: Emotionally and physically stressful
CON: Side effects of hormones e.g. abdominal pain
, What are the ethical concerns linked to IVF? - answer IVF leads to unused embryos
which are destroyed or used for medical research. (Potential life).
Genetic testing could be carried out on the embryo which could lead to designed
babies.
What is the sclera? - answer The tough supporting wall of the eye
What is the cornea? - answer Outer transparent layer, bends/refracts light into the eye
What is the pupil? - answer The hole in the centre where light enters
What is the iris? - answer A muscle that controls the diameter of the pupil and how
much light enters. The coloured part of the eye.
What is the retina? - answer Contains receptor cells called rods and cones. These are
sensitive to colour and light intensity.
What is the lens? - answer Focuses the light into the retina
What is the ciliary muscles and suspensory ligaments? - answer Control the shape of
the lens
What is the optic nerve? - answer Carries impulses from the receptors on the retina to
the brain
Why is the iris reflex needed? - answer To prevent light from damaging the retina.
Explain the iris reflex in very bright light. - answer In very bright light a reflex is triggered
to make the pupil smaller. The CIRCULAR muscles CONTRACT and the RADIAL
muscles RELAX.
Explain the iris reflex in dim light. - answer In dim light a reflex is triggered to make the
pupil dilate. The CIRCULAR muscles RELAX and the RADIAL muscles CONTRACT.
Define accommodation. - answer Where the eye focuses light on the retina by changing
the shape of the lens.
Explain how the eye focuses on something that is near to it. - answer The ciliary
muscles contract which slacken the suspensory muscles. This causes the lens to
become fat (more curved) so increases how much light is bent.