Topic 5b - The Endocrine System Flashcards
What are hormones?
Hormones are chemical messengers which travel in the blood to activate target cells.
What is the endocrine system?
Hormones are produced in and secreted by various glands, called endocrine glands. These glands make up the endocrine system.
How does the endocrine system use hormones?
The endocrine system uses hormones to react to changes in the environment or changes inside the body.
What are the 6 glands in the endocrine system?
- Pituitary gland
- Thyroid gland
- Pancreas
- Testes
- Adrenal gland
- Ovaries
Where is TSH (Thyroid stimulating hormone) produced, and what is its target organ?
- Produced in thyroid gland
- Target organ in thyroid gland
Where is ADH (anti-diuretic hormone) produced, and what is its target organ?
- Produced in pituitary gland
- Target organ is kidneys
Where is FSH (follicle stimulating hormone) produced, and what is its target organ?
- Produced in pituitary gland
- Target organ is ovaries
Where is LH (luteinising hormone) produced, and what is its target organ?
- Produced in pituitary gland
- Target organ is ovaries
Where are insulin and glucagon produced, and what are their target organs?
- Produced in pancreas
- Target organs are muscles and liver
Where is adrenaline produced, and what are its target organs?
- Produced in adrenal gland
- Target organs are heart, liver and muscles
Where is oestrogen produced, and what are its target organs?
- Produced in ovaries
- Target organs are ovaries, uterus and pituitary gland
Where is progesterone produced, and what is its target organ?
- Produced in ovaries
- Target organ is uterus
Where is testosterone produced, and what are its target organ?
- Produced in testes
- Target organs are male reproductive organs
How are hormones and nerve impulses different in terms of speed, duration and effectors?
- Speed; hormones travel slower, and nerve impulses travel faster
- Duration; the effects of hormones last longer, and the effects of nerve impulses are shorter
- Effectors; hormones target cells in particular tissues, and nerve impulses have motor neurones which often end in muscles
What is the pituitary gland? (3)
- The pituitary gland is a ‘master gland’.
- It secretes several hormones in response to body conditions.
- These hormones then act on other glands, stimulating the release of other hormones.
What are changes in blood glucose levels monitored by?
The pancreas.
What is insulin?
Insulin is a hormone produced by the pancreas. It decreases the blood glucose level when it gets too high.
What is the 4 step process of the body’s reaction to blood glucose levels being too high?
- Blood with too much glucose, is detected by pancreas.
- Insulin secreted by pancreas into the blood.
- Insulin causes body cells to take up more glucose from the blood. Cells in the liver and muscles can take up glucose and convert it into a storage molecule (polysaccharide) called glycogen.
- This causes the blood glucose level to fall back to the optimum level.
What is glucagon?
Glucagon is a hormone produced by the pancreas. It increases the blood glucose level when it gets too low.
What is the 4 step process of the body’s reaction to blood glucose levels being too low?
- If a person’s blood glucose level decreases, the fall is detected by the pancreas.
- The pancreas responds by producing glucagon, which is secreted into the blood.
- Glucose can be stored in the muscles and liver as glycogen. Glucagon causes the glycogen to be converted back into glucose, which enters the blood.
- This causes the blood glucose levels to rise.
When do type 1 and 2 diabetes occur?
They occur when the normal hormonal control of blood glucose concentration is disrupted.
What is type 1 diabetes?
Type 1 diabetes is a condition where your immune system attacks the pancreas, in turn destroying the cells that produce insulin, meaning little or no insulin is produced. The result is that a person’s blood glucose can rise to a level that can kill them.
What is type 1diabetes characterised by?
It is characterised by uncontrolled high blood glucose levels.
How is type 1 diabetes usually treated?
It is normally treated by monitoring blood glucose levels and injecting human insulin throughout the day (particularly after meals consumed).
Who does type 1 diabetes affect?
A relatively small % of the population - mainly young people.
What is type 2 diabetes?
In Type 2 diabetes the body cells become resistant to insulin produced by the pancreas, so much so that the pancreas can’t compensate regardless of how much insulin there is.
What are the risk factors of type 2 diabetes? (5)
- If other family members have it
- Age
- Weight => 80-85% of people with type 2 diabetes are overweight
- Lack of exercise
- Lack of healthy diet
Why is obesity a risk factor for type 2 diabetes?
Because a person who is obese may consume a diet high in carbohydrates, and over-production of insulin results in resistance developing.