B11 - Hormonal coordination Flashcards
B11 - What is the Endocrine system?
An organ system
Many glands that secrete chemicals called hormones
B11 - What is a hormone?
A chemical messenger.
Released from a gland.
Transported in the blood stream.
Has an effect on a target organ.
B11 - List the major glands in the body
Pituitary
Thyroid
Pancreas
Adrenal
Testes
Ovaries
B11 - What does each gland do?
Pituitary - Controls growth, stimulate other glands
Thyroid - controls metabolic rate
Pancreas - controls blood sugar
Adrenal - produces adrenaline
Testes - produces sperm and controls secondary sex characteristics in men
Ovaries - egg production and controls secondary sex characteristics in women
B11 - Explain why the pituitary gland is called a master gland.
Secretes a wide range of hormones.
These hormones stimulate other glands to begin production of different hormones.
B11 - Which two hormones are involved in the regulation of blood glucose?
Insulin - lowers blood glucose.
Glucagon - raises blood glucose.
Both produced by the pancreas.
B11 - Explain what happens when blood glucose levels get too high.
Blood glucose levels rise above their normal level.
The pancreas secretes insulin.
Insulin causes the glucose to:
-Be taken up by the cells
-Used in cellular respiration
-Converted to fat for storage
-Converted to glycogen in the liver
Blood glucose levels return to normal.
B11 - Explain what happens when blood glucose levels get too low.
Blood glucose levels fall below their normal level.
The pancreas secretes glucagon.
Glucagon causes:
-The production of glucose from amino acids and fats
-The breakdown of glycogen in the liver to glucose.
Blood glucose levels return to normal.
B11 - What happens in type 1 diabetes?
Your pancreas does not produce enough insulin.
Caused by genetic factors or damage to pancreas.
Treated with insulin injections, regular exercise or dietary modifications.
B11 - What happens in type 2 diabetes?
Your cells stop responding to insulin.
Usually affects older adults.
Caused by obesity and lack of exercise.
Treated with dietary modifications and regular exercise.
B11 - What are the roles of the four hormones involved in the menstrual cycle?
FSH - causes eggs to mature in the ovary.
Oestrogen - stops FSH and starts LH production.
LH - causes an egg to be released.
Progesterone - maintains lining of uterus.
B11 - Explain how fertility changes with age in women.
Fertility decreases with age.
A women is born with a set number of eggs.
One will be released every month.
Eventually she will run out.
When there are no more eggs left she will no longer be able to have a child.
B11 - Explain how fertility changes with age in men.
A man remains fertile throughout his entire life.
The testes will produce sperm continuously.
Sperm quality decreases with age.
Increases the risk of conceiving a child with a genetic disorder.
B11 - What are the advantages of IVF
Best way for a woman to have a baby using her own eggs.
Increases the chances of older women conceiving.
Reasonably safe.
Can help single women and same sex couples who want children.
Unused embryos can be donated for research.
B11 - What are the disadvantages of IVF
Expensive (£5000 per cycle).
Not always successful.
Emotionally and physically stressful.
Increased risk of multiple pregnancies.
Fertility drugs have side effects.
