B11 Hormonal Coordination Flashcards
What is the endocrine system
The glands and organs that make hormones and release them into the blood so they can travel all over the body
Name the the 6 glands in the endocrine system, the hormone they produce and their role
PTAPOT
Pituitary-‘Master Gland’ - Tell the body what to do and tell other gland to release hormones
Thyroid-Thyroxine - Regulate rate of metabolism and growth and development
Adrenal-Adrenalin - Fight of flight response, increase heart rate
Pancreas-Insulin - Regulate blood glucose concentration
Ovaries-Oestrogen - Hold eggs
Testis-Testosterone - Produces sperm
Compare the endocrine system to the nervous system
The nervous system send electrical impulses transported by nerve cells so are very fast and effects dont last long
Endocrine system relies on the blood for transportation so signals travel slower but effects last longer
Endocrine system acts generally over the whole body whereas nervous system acts in one specific area
What 3 organs in the body does controlling blood sugar involve
Liver
Kidneys
Pancreas
What is insulin
Released when blood glucose is high-Lowers it
What is glucagon
Released if blood glucose is low-Increases it
What is glycogen
A long term storage molecule made up of glucose units
What is the body’s reaction to a rise in blood glucose
Beta cells in the pancreas secrete insulin
This causes an uptake of glucose by body cells which is then turned into glycogen and fat
Results in decreased levels of glucose in the blood
What is the body’s reaction to a fall in blood glucose
Alpha cells in pancreas secrete glucagon
This causes the conversion of glycogen into glucose
Results in glucose being released into blood, increasing levels
What is diabetes
When blood glucose concentration is not well controlled by the body
What is the cause of diabetes
Type 1-The pancreas does not produce enough insulin-Due to genes, the immune system attacks the pancreas
Type 2-The cells of the body dont respond to the insulin produced
How can you cure type 1 diabetes
Use stem cells from human embryos and genetically engineer these to make insulin-No risk of rejection but could cause ethical concern
Pancreas transplant-Difficult, risky, not enough donors, immunosuppressants taken instead of insulin
Transplanting pancreatic cells from both dead and living donors has been tried with limited success
How can you treat type 1 diabetes
Insulin is injected and allows glucose to be converted to glycogen in the liver and stops the concentration of glucose in your blood becoming too high
How can you treat type 2 diabetes
Body cells no longer respond to insulin made by the pancreas, this can be treated by:
Eating a balanced diet-Controlled carbs
Losing weight
Regular exercise
There are also drugs that:
Help insulin work better on the body cells
Help your pancreas make more insulin
Reduce the amount of glucose you absorb from your gut
What is negative feedback
If a factor in the internal environment increases or decreases, changes take place to restore it too its original level
What does thyroxine control
Basal metabolic rate
How are thyroxine levels controlled
If thyroxine levels are high, the levels of thyroid stimulating hormone(TSH) ,made by the pituitary gland, is low so levels return to normal
And vice versa
What are the 4 hormones in the menstrual cycle and where are they produced
Fat Old Lady Pants
FSH-Follicle stimulating hormone-Causes eggs to mature-Pituitary gland
Oestrogen- Stimulates build up and maintenance of uterus lining-Ovaries
LH-Luteinising hormone-Stimulates release of egg-Pituitary gland
Progesterone-Maintenance of uterus lining during pregnancy-Ovaries
What happens during the menstrual cycle
Each month eggs begin to mature in the ovaries
At the same time the uterus produces a thickened lining ready for periods
Every 28 days a mature egg is released-ovulation
If the egg is not fertilised the lining of the uterus is shed along with the egg-Menstruation
What is fertility
The ability to reproduce successfully
What is contraceptive
Something that reduces the risk of a woman becoming pregnant by preventing the egg and sperm meeting or a fertilised egg implanting in the uterus
How cam you increase the chances of pregnancy
FSH treatment can stimulate the maturation of eggs prior to IVF treatment-Fertility drugs contain FSH
How can you reduce the chances of pregnancy
Oestrogen and progesterone containing pill that inhibits the production of FSH
What is IVF
Combining the egg and sperm in a petri dish so fertilisation takes place outside the body
What can cause infertility
Low sperm count
Cancer treatment
Failure to ovulate
Low quality sperm
Age
Obesity
No cause
Why can women fail to ovulate and how can you treat it
Dont produce enough FHS
Artificial FSH or LH can be used to trigger ovulation
What is the process of IVF
Mother is given synthetic FSH to stimulate maturation of eggs followed by LH to bring the eggs to the point of ovulation
Eggs are collected and placed in a petri dish
Eggs are fertilised with fathers sperm in a lab
Fertilised eggs are kept in special solution and develop into tiny embryos
Embryos are inserted back into uterus
What are the pros and cons of IVF
Pros-
Gives infertile couples the ability to have children
Mature eggs can be collected and stored for future pregnancy’s
Cons-
Expensive
Not always successful
May result in multiple births
Health risks
What do hormones in plants control
Directional growth of roots and shoots
Seed germination
Fruit formation and ripening
What is a tropism
When plants respond quickly to stimuli
What are the 2 main types of tropisms
Positive tropism-Grows towards stimuli
Negative tropism-Grows away from stimuli
What is phototropism
The response to light
What are auxins
Plant hormones that control cell elongation- Mostly made in tips of roots and shoots and can diffuse to other parts of the roots and tips
How does auxin cause plants for grow towards the light source
If more light reaches one side of the tips there will be a greater concentration of auxin on the shaded side causing these cells to elongate and the plant bends towards the light
What is gravitropism
Response to gravity
How does auxin affect the growth of plants
Auxin in roots slows down elongation therefore the side with least auxin grows most
