B12 Flashcards
What is urea?
Nitrogenous waste produced by the breakdowns of excess amino acids in your liver, passing from your liver into the blood. It is filtered out by blood in your kidneys.
When is urea produced?
It is produced when you eat excess protein or when your tissues are worn out so the excess protein cannot be stored in the body and has to be broken down. As amino acids can’t be used as fuel directly, your liver removes them by deamination, forming ammonia, which is converted to urea.
What is the function of the kidneys?
They conserve water, get rid of water, remove mineral ions and excrete them in your urine.
How do the kidneys work?
They filter your blood and move out glucose, minerals, urea and water. The blood cells and large proteins don’t go through the kidney tissues as they are too large.
What is selective reabsorbsion?
When all the glucose is reabsorbed into the blood by diffusion and active transport. However the amount that is reabsorbed varies, which is known as selective reabsorption.
What is ADH?
It is secretes by the pituitary gland, where receptor cells detect the concentration of the blood plasma. If it becomes too concentrated, ADH is released, however this means more water is absorbed so small concentrated amounts of urine are released.
What is dialysis?
The function of the kidney being carried out artificially.
How is dialysis carried out?
It controls the amount of substances in blood by using dialysis fluid with the same concentration of glucose and mineral ions as the blood of a person without kidney disease, so there is no net movement of glucose out the blood. Any excess ions of plasma is removed, into the machine down the concentration gradient, leaving the blood plasma levels normal. However there is no active transport so they need to keep urea low as the dialysis machine has none.
Negatives of dialysis?
Follow a controlled diet, long dialysis sessions.
What is the problem of kidney transplants?
There are not many, they could be rejected by the antigens, however if they use a close tissue type or immunosuppressant drugs they are less likely to be rejected.
