Homework Question on Blood body fluids and electrolytes
- Compare and contrast the handling of urea and Creatinine by the nephron
- Discuss the advantages and disadvantages of use of (a) urea (b) Creatinine to estimate GFR
- Enumerate the clinical advantages of body fluid cytology
- Define the following term; Proteinuria, Micro albuminuria ,Nephritic range Proteinuria, Nephrotic range Proteinuria, Overflow Proteinuria ,Selective ProteinuriaDescribe renal blood supply including interlobar, arcuate, and interlobular arteries and veins
- Describe renal blood supply including interlobar, arcuate, and interlobular arteries and veins
Homework Answer on Blood body fluids and electrolytes
- Compare and contrast the handling of urea and Creatinine by the nephron
Creatinine and urea are nitrogenous metabolism wastes. Urea comes from tissue protein turnover and dietary proteins while creatinine is excreted from muscle craetinine catabolism. In the nephron, there is a counter-current exchange process functioning in the loops. The concentration of Urea is optimized if there is an excess increase of urea in the outer medulla of the nephron. Upon the addition, urea remains in the tubular system until it gets reabsorbed from collecting ducts in the inner medulla. The addition of urea within the outer medullar highly enhances accumulation of urea unlike in the inner medulla, where urinal concentrationtends to be defeated and hence need for urinal concentration optimization.
According to Moulouel (761), “there is usually a high interstitial concentration of urea within the mammalian kidney which is very important since it allows excretion of nitrogenous waste in the form of urea and at the same time, minimizing urinary loss of water that would result from the effect of osmosis of the urea solute”.Creatinine formation starts from the kidney where a component called guanidoacetic acid is first formed. The component is then carried to the liver where creatinine is formed before getting into the circulation system.
The kidneys have the key function of excreting creatinine.Unlike urea, it is not reabsorbed or affected by urine rate flow. Since they are very small molecules, the glomerulus filters it freely. It is usually secreted by the tubules in small and significant amounts. Excretion of both wastes increases upon exercising without producing a change in the concentration of serum.
- Discuss the advantages and disadvantages of use of (a) urea (b) Creatinine to estimate GFR
GFR is mostly assessed by monitoring the concentration of endogenous serum makers like creatnine and blood urea nitrogen. These endogenous makers are widely used but sometimes are not ideal in some clinical settings.