Final answer:
The correct formula for determining clearance is option 2, which is: Clearance = (urine concentration x urine flow rate) / plasma concentration. This formula is used to calculate the clearance of a substance from the plasma by the kidneys and is directly related to the glomerular filtration rate (GFR), an important measure of kidney function.
Step-by-step explanation:
The correct equation for determining clearance is: Clearance = (urine concentration x urine flow rate) / plasma concentration. This formula reflects the volume of plasma from which a substance is completely cleared via the kidneys over a certain time period. It can be expressed as:
Clearance (C) = U x V / B
where:
- U represents the substance's concentration in urine,
- V is the urine flow rate,
- B is its concentration in blood plasma.
The value of clearance is influenced by the glomerular filtration rate (GFR), which indicates how well the kidneys filter blood. Creatinine, a metabolic waste product, is commonly used to estimate GFR as it is freely filtered by the kidneys and is an indicator of the excretory function of the kidneys.
Therefore, option 2 from the given list accurately reflects the formula used to calculate clearance: Clearance = (urine concentration x urine flow rate) / plasma concentration.