GFR and Filtration Flashcards
In order what is the blood supply to and through the kidney?
Aorta, renal A, segmental A, lobar A, arcuate A, interlobular A, afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries --> interlobular vein
Describe the cortical nephron
Start high in the cortex
Short loop of Henle = does not penetrate deep into medulla
Describe the juxtamedullary nephrons
Start low in the cortex near the medulla
Long loop of Henle = penetrates deeply into medulla
Loop of Henle surrounded by vasa recta
What is the vasa recta?
Straight arterioles of the juxtamedullary nephrons
What is renal blood flow?
~1.1L/Min
What is renal plasma flow?
Volume of blood plasma delivered to the kidneys per unit time
605 mL/min
How much blood at any one time is filtered in the glomerulus?
20% filtered
80% leaves via efferent arteriole
What is the renal corpuscle?
Glomerulus + bowmans capsule
Site of filtration of blood plasma
Function = prod ultra filtrate of plasma
Why is it important that the DCT sits back up against it own glomerulus?
Regulatory ability
Communication between
Tubular glomerular feedback
What arrangement makes up the glomerula tuft?
Capillary
Surrounded by basement mem
On which sit podocytes that have projections (pedicels), with filtration slips between
Briefly outline the selective process of glomerular filtration
Freely ass = water, salts, small molecules
Dont get filtered = cells, large proteins
What are the layers of the filtration barrier?
1) capillary endo = permeable
2) basement mem = acellular gelatinous, permeable to small proteins, glycoprotein -ve charge repel protein movement
3) podocyte layer = pseudopodia interdigitate
What is the effect of charge and size of filtration selectivity?
Size = bigger, less go through
Charge = adding +ve charge mean filtration can tolerate bigger molecules as not repelled by -ve glycoproteins
What is proteinuria?
Presence of protein in the urine due to high levels of protein
What are the physical forces involved in filtering of plasma to form ultra filtrate?
Hydrostatic pressure in capillary (Pgc) = favours filtration
Hydrostatic pressure in bowmans capsule (Pbc) = opposes filtration
Oncotic pressure diff between capillary and tubular lumen (pie gc) = opposes filtration
Net driving force = inward movement to the bowmans capsule
