The Endoctrine System And Controlling Blood Glucose Flashcards
What is the other way to send information around the body (apart from along nerves)?
Using hormones
What are hormones?
Chemical molecules released directly into the blood. They are carried in the blood to other parts of the body, but only affect particular cells in particular organs (target organs).
Where are hormones produced and what are they secreted by?
They are produced in and secreted by various glands, called endoctrine glands.
Effects of hormones (long-lasting?)
Relatively long-lasting effects
Examples of glands (six)
The Pituitary gland Ovaries -females only Testes - male only Thyroid Adrenal gland The Pancreas
What does the Pituitary gland do?
Produces many hormones that regulate body conditions. These hormones act on other glands, directing them to release hormones that bring change.
What do the ovaries do?
Produce oestrogen, which is involved in the menstrual cycle
What do the testes do?
Produce testosterone, which controls puberty and sperm production
What does the thyroid do?
Produces thyroxine, which is involved in regulating things like the rate of metabolism, heart rate, and temperature.
What does the adrenal gland do?
Produces adrenaline, which is used to prepare the body for a ‘flight or fight’ response.
What does the pancreas do?
Produces insulin, which is used to regulate the blood glucose level.
Major 3 differences between nerves and hormones
Nerves have very fast action, whereas hormones have slower action.
Nerves act for a very short time, whereas hormones act for a longer time.
Nerves act on a very precise area, whereas hormones act in a more general way.
Why do nerves need to act faster than hormones?
Some information needs to be passed to the effectors really quickly, like pain signals, or information about danger you see from your eyes to your brain. Hormones would be too slow and no good here.
Example of a hormone acting for a longer time
When you get a shock, a hormone called adrenaline is released into the body. This causes the fight or flight response and prepares the body for action. You can tell this is hormonal because you feel a bit wobbly for a while afterwards.
Blood glucose is also controlled as part of …..?
Homeostasis
What are the two hormones involved in the control of blood glucose in homeostais?
Insulin and glucagon
How does the body control blood glucose (not mentioning insulin and glucagon)?
1) Eating foods conating carbs puts glucose (type of sugar) into the blood from the gut
2) Normal metabolism of cells removes glucose from the blood
3) Vigorous excerise removes much more glucose from the blood
4) Excess glucose can be stored as glycogen in the liver and in the muscles
In summary why does the body use insulin and glucagon to control the level of glucose in the blood?
The level of glucose in the blood must be kept steady. Changes are monitored and controlled by the pancreas, using the hormones insulin and glucagon, in a negative feedback cyle.
Explain the negative feedback cycle of insulin and blood glucose level (edit)
If the blood glucose level is too HIGH, insulin is added.
- The blood has too much glucose
- Insulin is then secreted by the pancreas
- Then there may still be too much glucose but there is insulin as well
- Glucose and insulin move from the blood into the liver and muscle cells
- The insulin the liver turn the glucose into glycogen.
- Blood glucose is reduced
Explain the negative feedback cycle of glycagon and blood glucose level (edit)
If the blood glucose level is too LOW, glucagon is added.
- The blood has too little glucose
- Glucagon is secreted by the pancreas
- There is still too little glucose, but there is glucagon as well.
- Glucagon goes to the liver
- The glucagon makes the liver turn glycogen into glucose
- The glucose is relased into the blood by the liver
- The blood glucose is increased
What is diabetes?
A condition that affects your ability to control your blood sugar level.
What does Type 1 diabetes mean for a person?
This is where the pancreas produces little or no insulin, meaning that a person’s blood glucose can rise to a level that can kill them.
How is type 1 diabetes treated?
They need insulin therapy
Limit intake of food rich in simple carbohydrates, e.g. sugars (which cause the blood glucose to rise rapidly)
Take regular excericise, which helps to remove excess glucose from the blood
Explain how insulin therapy is used to treat type 1 diabetes
This usually involves several injections of insulin throughout the day, mostly at mealtimes, making sure that the glucose is removed from the blood quickly once the food has been digested, stopping the level getting too high. It’s a very effective treatment.
What does the amount of insulin that needs to be injected depend on?
The person’s diet
How active the person is
What does type 2 diabetes mean for a person?
This is where a person becomes resistant to their own insulin, so they still produce insulin, but their body cells don’t respond properly to the hormone. This can also cause a person’s blood sugar level to rise to a dangerous level.
How can type 2 diabetes be controlled?
Eating a carbohydrate-controlled diet
Getting regualr excercise
What can increase your chance of developing type 2 diabetes?
Being overweight, as obesity is a major risk factor in the development of the disease.
Equipment for maths
Protractor and compass
Reminder
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