Transcript Slide 1
Kidney Function • Regulate the composition of your About 1200mL of blood is filtered thru the kidney each minute!!!! • • • blood – keep the concentrations of various ions and other important substances constant – keep the volume of water in your body constant – remove wastes from your body (urea, ammonia, drugs, toxic substances) – keep the acid/base concentration of your blood constant Help regulate your blood pressure Stimulate the making of red blood cells Maintain your body's calcium levels Kidney Functions Urea from amino acid breakdown, Creatinine from creatine phosphate breakdown during muscle contraction, uric acid from recycling RNA.. Looking a little closer…. In a normal human adult, each kidney is about 12 cm long and about 5 cm thick, weighing 150 grams The Nephron Aldosterone Regulated pump Na+ reclaimed K+ lost Anti-diuretic (ADH) Hormone controls passive water re- absorption by altering permeability FILTRATION About 20% of the fluid brought to the kidney leaves the blood in the Glomerulus. It must be reabsorbed to prevent dehydration. (180L/day) At this point approximately 1200mL of urine is produced/day and 90% of the water and nutrients that left the blood have been reabsorbed. Rids body of : urea and ammonia from amino acid breakdown, Creatinine from creatine phosphate breakdown during muscle contraction, uric acid from recycling RNA, and excess water. http://home.comcast.net/~john.kimball1/BiologyPages/K/Kidney.html The Mechanism of Dialysis • Blood flows by one side of a semipermeable membrane, and a dialysis solution or fluid flows by the opposite side. Most smaller solutes can easily pass through the membrane. The Unhealthy Kidney • In the diseased kidney, dialysis is a type of renal replacement therapy, which is used to provide an artificial means for lost kidney function. • Dialysis can be for acute kidney failure or permanent kidney failure. • The semi-permeable membrane used in dialysis to perform the function of the nephron is the same as the membrane you are using in your experiment. The Mechanics The concentrations of undesired solutes (among them potassium, urea, and phosphorus, but including a large number of compounds about which little is known) are high in the blood, but low or absent in the dialysis solution. • www.biotopics.co.uk/human2/andial.html • The dialysis solution is continually replenished to maintain the concentration gradient for the removal of unwanted solutes. The dialysis solution has levels of minerals like sodium and chloride that are similar to their natural concentration in healthy blood. For another solute, bicarbonate, dialysis solution level is set at a slightly higher level than in healthy blood. This is to encourage diffusion of bicarbonate from dialysate to the blood, to neutralize the buildup of acidity acidosis that is often present in these patients. • http://www.blobs.org/science/diffusion/imgs/diffusion2.gif Hemodialysis and peritoneal dialysis In our experiment…. What happened to the glucose and the starch? How do you know?