Urine Production: Filtration Flashcards
what metabolic waste products are made in the liver?
urea
creatinine
bilirubin
where is urea reabsorbed?
- most reabsorbed in PCT (30-40%)
- small amount in medullary collecting duct
what is creatinine made from?
muscle breakdown
how much creatinine is reabsorbed in the kidney?
none
what is bilirubin made from?
breakdown of RBC
name the steps of urine production
- filtration in glomerulus
- reabsorption in PCT
- counter-current concentration in loop of Henle (& collecting duct)
- secretion in DCT
- excretion in collecting duct
what is the first step of urine production?
filtration
where does filtration occur?
glomerulus
what is the osmolarity in the glomerulus?
300
how much blood is in the kidney at all times?
20%
glomerular filtration is based on ____
size
the glomerulus is composed of…
fenestrated capillaries reinforced by basement membrane, and podocytes (slit pores)
what is the normal glomerular filtration rate (GFR)?
~125 mL/min
how does filtrate compare to plasma?
same but no protein
what is the equation for filtered load?
plasma concentration x GFR