C12 - Kidney failure Flashcards
What are the two major roles of the kidney?
Excretion
Osmoregulation
What happens if the kidney fails
Unable to remove urea,
so concentration increases to toxic levels
unable to remove excess water
so body fluids increase in volume and are diluted
compromising metabolic reactions.
What are the 5 common cause of kidney failure
Diabetes High blood pressure auto immune diseases infection crushing injuries
What is the effect of having diabetes
High glucose concentration in the plasma which results in the glomeruli losing protein(albumin),
into the filtrate and causes some of the proteins to link together
Triggering scarring in a condition called Glmerulosclerosis
What is the effect of having high blood pressure
Can lead to damaged capillaries of the glomerulus which can prevent ultra filtration
What is the effect of having an autoimmune disease
The body makes antibodies against its own tissues
What prevents ultrafiltration from occurring
Blood pressure too high or low
Damage to the capillaries
What are examples of treatments when both kidneys fail
Reducing intake of certain nutrients (protein) to reduce urea formation and ion e.g. calcium and potassium
Using drugs to reduce blood pressure
The concentrations of dissolved potassium and calcium ions are normally maintained by a balance of absorption in the small intestine and by selective reabsorption by the nephrons
Dialysis
Kidney transplant
What type of drugs can be used to help treat kidney failure
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers reduce the effect of angiotensin, a hormone that constricts blood vessels,
increasing the pressure of the blood within
Calcium channel blockers dilate blood vessels and reduce blood pressure
Beta-blockers reduce the effect of adrenalin, one effect of which is an increased blood pressure of the blood within
What can a high potassium concentration in the blood be treated
it is treated with a combination of glucose and insulin
if left untreated it can lead to heart arrhythmias so intravenous calcium is used in addition to stabilise heart muscle membranes
What can a high calcium concentration in the blood be treated by
Correlated with increased risk of
Heart disease
Kidney stones
Osteporosis
Treated via bisphosphonates which decrease the activity of osteoclasts
the cells that break down bone in its constnat recycling
calcium therefore accumulates in bone and less circulates in the blood
Describe how Dialysis works
The blood to be cleaned and a dialysis fluid are separated by a selectively permeable membrane
the dialysis fluid has the same water potential as the blood
but the fluid has a low ion concentration and no urea,
Inorganic ions water and urea diffuse out the blood across the membrane
down their concentration gradients
the dialysis fluid contains glucose at the normal concentration of the blood
so none diffuses out of the blood
When might a kidney transplant be used
in a patient, with end,-stage renal disease may be offed a kidney transplant
Describe the basics of hemodialysis
uses a dialysis machine
blood taken from an artery ussually in an arm
Run through thousands of long narrow fibres made of selectively permeable dialysis tubing
Fibres surrounded byh the dialysis fluid
Pores of tubing let molecules in solution out into the dialysis fluid run through the machine in opposite directions
enhancing diffusion
out of the blood by a counter current mechanism
the blood is returned to a vein
herparin is added to thin the blood and prevents clotting
A sensor in the dialysis fluid detects haemoblobin that would diffuse through if red blood cells were dammaged
patients routinely use a machine for several hours at a time
several days a week
Difference in life span of a dead donors kidney and a live donors kidney
surprise the live one works for longer than the dead donors
