Renal Physiology I - Wall Flashcards
Which ion determines size of the extracellular fluid volume?
Na
Which ion has the greatest effect on blood pressure?
Na
What is the major body anion?
Cl
What are the major waste products that the kidney is in charge of clearing?
Urea (from protein), creatinine (from muscle metabolism), and uric acid (from nucleic acid metabolism)
What is 1-alpha hydroxylase?
Enzyme in kidney in charge of final synthesis step for active vitamin D
What is bradykinin?
A vasodilator important for regulating vasofiltration rates
What are the three ways through which the kidney as an organ maintains blood pressure?
1) Homeostasis of Na and H20
2) Controling renin-angiotensin system
3) Producing vasodilatory substances
Does the kidney have an important role in regulating insulin levels?
Yes because it excretes insulin. In instances of kidney atrophy, less cleared insulin means hyperglycemia
What is neutral balance?
Diet intake + endogenous production = excretion rate
What is positive balance?
Intake + endogenous production > excretion, leading to increased total body content
What is negative balance?
Intake + endogenous production < excretion, leading to decreased total body content
About how much of the glomerular filtrate is reabsorbed?
~99%
How does filtrate differ from blood?
Filtrate doesn’t have cells or large proteins
What is always the best measure of overall kidney function?
GFR
Is water ever secreted into the tubule downstream from the glomerulus?
NO
Where are the kidneys located anatomically?
Retroperitoneal from T12-L3
Which part of the kidney is most perfused?
Cortex, with about 98% of total kidney flow
What is the area called where the ureters, vessels, lymphatics, and nerves enter the kidney?
Renal hilus
What type of anemia would you expect to see in someone with a reduced-function kidney?
Less EPO leads to low reticulocytes and thus a normocytic normochromic anemia
What is the function of prostaglandins secreted by the kidney?
Autoregulation of CFR, particularly via PGI2 and PGE2
What is endothelin?
Made during endothelial injury; very powerful vasoconstrictor
How is potassium eliminated by the kidney?
Secretion (as opposed to filtered out at the glomerulus)
Where do the glomeruli reside in the kidney?
Cortex
Describe the flow of urine from the collecting duct
Duct –> papilla –> minor calyx –> major calyx –> renal pelvis