4.5.3 Hormonal coordination in humans (will come up) P2 2 Flashcards
What is osmosis
The movement of water from a dilute solution to a concentrated solution through a semi permeable membrane
In what ways is water lost from the body
During exhalation via the lungs
Sweating
Urine (sometimes reabsorbed in the kidney)
In what ways are ions lost from the body
Sweating
Urine (some reabsorbed in the kidney)
How are excess amino acids excreted from the body
Excess amino acids are deaminated in the liver to form ammonia
Ammonia is toxic so it is converted into urea
Urea is excreted from the body via sweat and urine
How do the kidneys maintain the balance of water and other substances in the body
Filter blood in order to remove waste products eg urea
Selectively reabsorb useful molecules eg glucose, water, ions
What is the full name of the hormone ADH
Anti-diuretic hormone
Where is ADH secreted in the body
The pituitary gland of the brain
How does ADH affect the reabsorption of water in the kidneys
When the blood is too concentrated the pituitary gland secretes more ADH
ADH travels in the bloodstream to the kidney and increases the permeability of kidney tubules to water
More water is reabsorbed in the kidneys, resulting in a smaller volume of more concentrated urine
Why is kidney failure dangerous
When the kidneys are damaged, they may be unable to filter the blood properly This may lead to:
A build up of toxic molecules eg urea in the body
An uncontrolled ion and water balance and cells being damaged as a result of osmosis
2 main ways of treating kidney failure
Dialysis
Transplant
What is kidney dialysis
Kidney dialysis is the use of a special machine to carry out the function of kidneys
Dialysis fluid contains the same concentration of glucose and ions as healthy blood
As a result, only excess and waste molecules are lost from the blood and glucose and ions remain
What happens if cells lose or gain too much water by osmosis
they do not function efficiently
