B9 The Endocrine System Flashcards
What kind of glands secrete hormones?
Endocrine glands
Why is the pituitary gland referred to as the ‘master gland’?
It releases hormones that stimulate other endocrine glands.
List 3 differences between nervous responses and hormonal responses:
- Nervous responses travel faster
- Hormonal responses are longer lasting
- Nervous impulses act on a more precise region
List 2 processes that remove glucose from the blood:
- Cell metabolism
- Vigorous exercise
List 3 ways of controlling Type 1 diabetes:
- Insulin therapy
- Limit simple carbohydrates
- Regular exercise
How does insulin control blood sugar levels?
It triggers the uptake of glucose into muscle and liver cells, which convert it to the storage molecule glycogen.
How do the kidneys make urine?
By extracting waste products from your blood by filtering them out
What substances are removed from the body in urine?
Urea, excess ions and water
How is water lost from the body? (excluding urine)
Sweat and exhalation
Why may you produce less urine on a hot day?
To preserve water as some may be lost through sweat
Why is it important to control the ion content in the blood?
Having an unbalanced ion content could affect the way water is drawn into cells via osmosis, affecting their functions.
What is the process of converting excess amino acids called and where does this take place?
Deamination- in the liver
What products and by-products are formed during deamination?
Fats, carbohydrates and ammonia
What is ammonia converted to in the body?
Urea
What is the role of antidiuretic hormone?
It acts on the kidney tubule cells, making them more permeable, thus changing the amount of water that is absorbed.
In what part of the kidney does filtration and selective reabsorption take place?
In the kidney tubules
Which gland secretes ADH?
The pituitary gland
What substances are reabsorbed back into the blood from the kidneys?
Glucose, amino acids, some water and ions
Which part of the brain detects when water levels are imbalanced?
Hypothalamus
Aside from in urine, how are ions removed from your body?
In sweat
Why is ion content primarily maintained by the kidneys, and not sweat?
The amount lost in sweat is unregulated.
What are the 2 main treatments for kidney failure?
Transplants or dialysis
How does a dialysis machine work?
The person’s blood flows through a tube alongside a semi-permeable membrane containing dialysis fluid. The membrane allows smaller molecules to diffuse across.
How do dialysis machines ensure that exactly the right amount of waste is removed?
The dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood, so useful substances will not diffuse across; only excess water, ions and urea.
What are 3 disadvantages of dialysis?
- Sessions are long (3-4 hours, often several times a week)
- Can lead to infections
- Expensive
What is a potential risk of kidney transplantation?
The recipient’s immune system could reject the donor organ.
How does organ rejection occur?
The antigens on the donor cells may not be recognised by the recipient’s white blood cells, which will then produce antibodies against them.
List 2 ways of preventing organ rejection:
- A donor with a similar tissue-type to the recipient is chosen (similar antigens on cells)
- Immunosuppressants
Define hormones
Chemical messengers that bring about change in target organs
Define selective reabsorption
The reuptake of useful substances into the blood from the kidneys
