GENERAL HISTOLOGY

Detailed explanation-1: -Fluid movement across a capillary wall is determined by a combination of hydrostatic and osmotic pressure. The net result of the capillary microcirculation created by hydrostatic and osmotic pressure is that substances leave the blood at one end of the capillary and return at the other end.

Detailed explanation-2: -Hydrostatic Forces The hydrostatic pressure in the intravascular space (Pc) is the principle force driving water and electrolytes out of the capillary into the interstitial space. The filtration force of the capillary hydrostatic pressure is opposed by the tissue pressure surrounding the capillaries (Pt).

Detailed explanation-3: -The net pressure that drives reabsorption-the movement of fluid from the interstitial fluid back into the capillaries-is called osmotic pressure (sometimes referred to as oncotic pressure). Whereas hydrostatic pressure forces fluid out of the capillary, osmotic pressure draws fluid back in.

Detailed explanation-4: -In contrast, the movement of fluid from an area of higher pressure in the tissues into an area of lower pressure in the capillaries is reabsorption. Two types of pressure interact to drive each of these movements: hydrostatic pressure and osmotic pressure.