Question

Edema may be caused by a. high blood pressure. b. decreased plasma protein concentration. c. leakage of plasma protein into the interstitial fluid. d. blockage of lymphatic vessels. e. all of these.

Short answer

Edema can be caused by all of the given factors: high blood pressure, decreased plasma protein concentration, leakage of plasma protein into the interstitial fluid, and blockage of lymphatic vessels. Thus, the correct answer is e. all of these.

Step-by-step solution

1. Understand Edema

Edema is the abnormal accumulation of fluid in the interstitial spaces within tissues, leading to swelling. It can result from various factors, including increased capillary pressure, decreased plasma protein concentration, leakage of plasma proteins, or blockage of lymphatic vessels.

2. Analyze possible causes

a. High blood pressure: High blood pressure can cause increased capillary pressure, forcing more fluid out of the capillaries and into the interstitial spaces. This can lead to edema. b. Decreased plasma protein concentration: Plasma proteins, particularly albumin, help maintain osmotic pressure in the bloodstream. A decrease in plasma protein concentration reduces the osmotic pressure in the blood, causing fluid to leak out of the capillaries and accumulate in the interstitial spaces, leading to edema. c. Leakage of plasma protein into the interstitial fluid: When plasma proteins leak into the interstitial fluid, they can pull more water out of the capillaries, increasing the volume of fluid in the interstitial spaces and causing edema. d. Blockage of lymphatic vessels: Lymphatic vessels help remove excess fluid from the interstitial spaces and return it to the bloodstream. When these vessels are blocked, fluid can build up in the interstitial spaces, leading to edema.

3. Determine the correct answer

As all of the given causes (high blood pressure, decreased plasma protein concentration, leakage of plasma protein into the interstitial fluid, and blockage of lymphatic vessels) can contribute to the development of edema, the correct answer is: e. all of these.