Kwashiorkor is a disease caused by a chronic protein deficiency. One might assume that a protein deficiency could only lead to a "skin and bones" appearance due to muscle tissue wasting away, but kwashiorkor actually causes severe edema (swelling). Why?

• A. The body compensates for the lack of protein by storing water around muscle tissue.
• B. The lack of protein causes an immune response, triggering inflammation.
• C. There isn't enough protein in the blood to act as a pH buffer, causing tissues to swell.
• D. There isn't enough protein to draw fluid back into the blood, causing it to accumulate in tissues.

Answer: (D)

Verified step by step guidance

1. Understand the role of proteins in maintaining fluid balance in the body. Proteins, particularly albumin, are essential for maintaining oncotic pressure, which helps draw water back into the blood vessels from surrounding tissues.
2. Recognize that a lack of dietary protein leads to a decrease in blood protein levels, particularly albumin. This reduces the oncotic pressure in the blood vessels.
3. When oncotic pressure is reduced, fluid that normally moves back into the blood vessels from the interstitial spaces (spaces between cells) remains in the tissues, leading to edema (swelling).
4. Clarify that this is not due to water being stored around muscle tissue, an immune response, or a pH imbalance, but rather due to the inability of the blood to reabsorb fluid effectively.
5. Conclude that the correct explanation is: 'There isn't enough protein to draw fluid back into the blood, causing it to accumulate in tissues.' This highlights the critical role of proteins in fluid balance and the consequences of protein deficiency.