Question

Normal values for glomerular blood hydrostatic pressure (GBHP), capsular hydrostatic pressure (CHP), and blood colloid osmotic pressure (BCOP) are 55 mmHg, 15 mmHg, and 30 mmHg, respectively. What would NFP be if blood pressure changes caused GBHP to increase to 60 mmHg?

Answer 1

Upon increasing the glomerular blood hydrostatic pressure (GBHP) to 60 mmHg, while capsular hydrostatic pressure (CHP) and blood colloid osmotic pressure (BCOP) remain unchanged, the new net filtration pressure (NFP) is calculated to be 15 mmHg.

Step-by-step explanation:

The net filtration pressure (NFP) in the kidneys is a vital determinant of the glomerular filtration rate. It is calculated as the difference between the glomerular blood hydrostatic pressure (GBHP) and the sum of the capsular hydrostatic pressure (CHP) plus the blood colloid osmotic pressure (BCOP). Let's calculate the updated NFP given the change in GBHP from 55 mmHg to 60 mmHg, while the values for CHP (15 mmHg) and BCOP (30 mmHg) remain constant.

Using the formula: NFP = GBHP - [CHP + BCOP], we substitute the updated GBHP and solve:

NFP = 60 mmHg - [15 mmHg + 30 mmHg]

NFP = 60 mmHg - 45 mmHg

NFP = 15 mmHg

The increase in GBHP results in an increase in NFP from the original value of 10 mmHg to 15 mmHg. This elevation signifies a potential increase in the glomerular filtration rate, demonstrating the kidney's capacity to regulate filtration autonomously in response to changes in blood pressure.