Hormones and Drugs Flashcards
(19 cards)
What are hormones?
Chemical messengers which travel in the blood to activate target cells.
What is the difference between nerves and hormones?
Nerves are very fast actions that act for a very short time .Hormones are slower actions that act for a long time.
Describe the stages of the menstrual cycle.
STAGE 1
Day 1- Bleeding starts, lining of the uterus breaks down for four days.
STAGE 2
Day 4- lining of the uterus builds up from day 4-14
STAGE 3
Day 14 An egg is released from the ovaries.
STAGE 4
Day 14-28 the wall is maintained for about 14 days until day 28, if no fertilised egg has landed on the uterus wall by day 28 the wall starts to break down again.
Where is FSH produced and what does it do?
Produced in the pituitary gland.
Causes an egg to mature in one of the ovaries.
Stimulates the ovaries to produce oestrogen.
Where is oestrogen produced and what does it do?
Produced in the ovaries.
Causes pituitary gland to produce LH.
Inhibits further release of FSH.
Where is LH produced and what does it do?
Produced by the pituitary gland.
Stimulates release of an egg at day 14.
How does the pill reduce fertility?
It contains oestrogen, which if taken daily to keep the levels high it inhibits the production of FSH and after a while egg development and production stop. It also contains progesterone which prevents any sperm getting through and reaching an egg.
What are the PRO’s and CON’s of taking the pill?
The pills over 99% effective at preventing pregnancy.
It reduces the risk of getting some time of cancer
There is still slight chance of getting pregnant.
Can cause side effects.
Doesn’t protect against STDS.
How can a woman increase her fertility?
The hormones FSH and LH can be injected by these women to stimulate egg releases in their ovaries.
Describe the process of IVF.
Eggs are collected from the womans ovaries.
They are fertilised in a lab using the mans sperm.
They are then grown into embryo’s, once the embryos are tiny balls of cells one or two of them are transferred to the woman’s uterus to improve the chances of pregnancy.
What are the problems with IVF?
Some women have a strong reaction to the hormones.
reports that there is an increased risk of cancer.
Multiple births.
What is auxin?
A plant hormone that controls growth near the tips of shoots and roots.
How do shoots grow towards light?
When the shoot tip is exposed to light, more auxin accumulates on the dark side causing the cells to grow faster on the shaded side. So the shoot bends towards the light.
How do roots grow towards gravity?
Auxin accumulates on the lower side of the root. In a root auxin inhibits growth so the upper side grows faster causing the root to bend downwards.
What is homoeostasis?
The maintenance of a constant internal environment.
What is an anabolic steroid?
a type of performance-enhancing drug that increases muscle size.
What are stimulants?
a drug which increases heart rate.
Explain the three main stages in drug testing.
1/ Drugs are tested on human cells and tissues in the lab
2/ Tested on live animals to see whether the drug works , to find out how harmful it is and the best dosage.
3/ Tested on human volunteers in a clinical trial- first healthy volunteers to see if the drug has any harmful side effects when the body is working normally.
If the results for the healthy volunteers are good, the drug is tested on people suffering from the illness, the optimum dose is found.
The group is split in two, one is given the real drug and the other is given a placebo.
Clinical trials are usually double-blind.
What was the problem with thalidomide, when it was given to pregnant women suffering from morning sickness?
It caused limb deficiencies in the babies because the drug was not originally trialled for pregnant women, it was only tested on people who could not sleep and used as a sleeping pill.
