The two components of extracellular fluid, the interstitial fluid and the blood plasma, are completely continuous separated by the cell walls within the cells of the body separated by the capillary walls
The two components of extracellular fluid, the interstitial fluid and the blood plasma, are
- completely continuous
- separated by the cell walls
- within the cells of the body
- separated by the capillary walls
The Correct Answer and Explanation is :
Correct Answer:
Separated by the capillary walls
Explanation:
Extracellular fluid (ECF) is the fluid found outside of cells and is divided into two main components: interstitial fluid (IF) and blood plasma. While both these fluids contribute to maintaining homeostasis and facilitating communication between cells, they are not completely continuous but rather separated by capillary walls.
Why Capillary Walls Separate Interstitial Fluid and Blood Plasma?
Capillary walls are composed of a single layer of endothelial cells with small gaps, called capillary pores, which regulate the exchange of substances between blood plasma and interstitial fluid. These walls act as a selective barrier, allowing water, oxygen, carbon dioxide, nutrients, and waste products to pass between these two compartments while restricting larger molecules like proteins.
- Blood Plasma:
- Found within blood vessels (arteries, veins, and capillaries).
- Contains water, ions, proteins (such as albumin), nutrients, hormones, and waste products.
- Responsible for transporting oxygen, nutrients, and metabolic waste throughout the body.
- Interstitial Fluid:
- Surrounds the cells, filling the spaces between them.
- Derived from blood plasma through capillary filtration.
- Provides nutrients and removes waste from cells before re-entering circulation.
Why Other Options Are Incorrect?
- “Completely continuous” → Incorrect, because the capillary wall controls exchange and does not allow unrestricted mixing.
- “Separated by the cell walls” → Incorrect, because cell walls do not exist in human cells (only in plants and bacteria).
- “Within the cells of the body” → Incorrect, because extracellular fluid is outside cells, while intracellular fluid is inside.
Thus, the correct answer is “separated by the capillary walls.”