How hydrostatic pressure causes edema?
Hydrostatic pressure building up within the blood vessels causes water to flow out of the blood vessels and into the surrounding tissue. This increases the concentration of protein in the plasma, which causes more fluid to be drawn back into the vessels from the tissue.
What are the four mechanisms of edema?
Edema can be divided into 4 types based on the mechanisms causing edema: increased capillary hydrostatic pressure, decreased plasma oncotic pressure, enhanced hydraulic permeability of capillary walls, and lymphatic obstruction. Each of the types can be further divided into generalized and local forms.
What increases hydrostatic pressure?
An increase in small artery, arteriolar, or venous pressure will increase the capillary hydrostatic pressure favoring filtration. A reduction of these pressures will have the opposite effect. Tissue pressure can change significantly if fluid moves into tissue space.
Does high hydrostatic pressure cause edema?
As left ventricular failure becomes more severe, or during right ventricular failure, blood backs up into the systemic venous circulation. This elevates venous pressures and capillary hydrostatic pressures, which can lead to edema especially in the feet and legs.
What happens when hydrostatic pressure is too high?
In other words, as the hydrostatic pressure gradient (PC – Pi) decreases owing to the rise in interstitial pressure, fluid filtration will be attenuated. However, large increases in tissue interstitial pressure can lead to tissue damage and cellular death.
What causes blood hydrostatic pressure?
Hydrostatic pressure is a force generated by the pressure of fluid on the capillary walls either by the blood plasma or interstitial fluid. The net filtration pressure is the balance of the four Starling forces and determines the net flow of fluid across the capillary membrane.
What causes hydrostatic edema?
Hydrostatic edema refers to accumulation of excess interstitial fluid which results from elevated capillary hydrostatic pressure while permeability edema results from disruption of the physical structure of the pores in the microvascular membrane such that the barrier is less able to restrict the movement of …
Why do vasodilators cause edema?
Vasodilatory edema, a common adverse effect of antihypertensive therapy with vasodilators, is related to several mechanisms, including arteriolar dilatation (causing an increase in intracapillary pressure), stimulation of the renin-angiotensin-aldosterone system, and fluid volume retention.
How do you lower hydrostatic pressure?
Glomerular filtration can be decreased by reducing capillary hydrostatic pressure with one of the following: (1) a decrease in glomerular blood flow as a result of low blood pressure or low cardiac output; (2) the constriction of the afferent arteriole as a result of increased sympathetic activity or drugs (e.g..
What does hydrostatic pressure do to the body?
The force of hydrostatic pressure means that as blood moves along the capillary, fluid moves out through its pores and into the interstitial space. This movement means that the pressure exerted by the blood will become lower, as the blood moves along the capillary, from the arterial to the venous end.