Final answer:
The term for the amount of dirt collected by a filter when the pressure reaches a predetermined point is 'filter cake.' Filtration media, including in human kidneys, use pressure differentials to determine when cleaning or replacement is needed, which are influenced by net filtration pressure (NFP).
Step-by-step explanation:
The amount of dirt collected by a filter when the pressure reaches a predetermined point is known as the filter cake. In filtration processes, especially when dealing with pressure filtration, the filtration media collects particulates until it reaches a point where the pressure indicates that the filter's capacity has been met.
This is commonly encountered in systems like water treatment facilities or in the glomerular filtration within the kidneys, where the filtration rate is driven by the net filtration pressure (NFP). The NFP is a critical factor that can be influenced by various types of pressures such as hydrostatic and osmotic pressures.
Proper filter maintenance, including the removal of filter cake, is essential to ensure effective filtration and protect against issues like systemic edema caused by an imbalance in the pressures that regulate bodily fluids.