Final answer:
The claim that colloid pressure is the primary regulator of water transfer between intracellular and interstitial fluid is false. Hydrostatic and osmotic pressures are the main forces responsible, with blood colloidal osmotic pressure (BCOP) influencing reabsorption of water into the capillaries.
Step-by-step explanation:
The statement 'Colloid pressure is the chief regulator of water transfer between intracellular and interstitial fluid' is false. The chief regulators of water transfer between intracellular and interstitial fluid are primarily the hydrostatic pressure and the osmotic pressure (sometimes referred to as oncotic pressure). These pressures determine the movement of water in and out of the capillary beds.
Colloid pressure, more specifically referred to as the blood colloidal osmotic pressure (BCOP), is critical in regulating the movement of water from the interstitial space back into the capillaries. This osmotic pressure is primarily due to plasma proteins such as albumin, which cannot pass through the capillary membrane and thus remain in the plasma. The BCOP is higher than the interstitial fluid colloidal osmotic pressure (IFCOP), which is very low. While BCOP plays a significant role in reabsorption at the venule end of the capillary, hydrostatic pressure is what initially drives the fluid out at the arteriolar end.