Which function is attributed to albumin in plasma?

Which function is attributed to albumin in plasma?

• A. Transports oxygen
• B. Keeps fluid contained in blood vessels so it doesn't leak into tissues
• C. Helps body fight infection
• D. Stores iron

Answer: (B)

Albumin’s main job in plasma is to maintain colloid osmotic (oncotic) pressure, which keeps fluid inside blood vessels. It’s the most abundant plasma protein produced by the liver, and its presence creates the pulling force that draws water back into the circulatory system at the capillaries. When albumin levels are adequate, fluid stays within vessels; when they’re low, fluid leaks into tissues, causing edema. Oxygen transport isn’t albumin’s role—hemoglobin handles that. Fighting infection is the job of immune components like antibodies and white blood cells. Iron storage is managed by proteins such as ferritin and transferrin, not albumin.

Albumin’s main job in plasma is to maintain colloid osmotic (oncotic) pressure, which keeps fluid inside blood vessels. It’s the most abundant plasma protein produced by the liver, and its presence creates the pulling force that draws water back into the circulatory system at the capillaries. When albumin levels are adequate, fluid stays within vessels; when they’re low, fluid leaks into tissues, causing edema.

Oxygen transport isn’t albumin’s role—hemoglobin handles that. Fighting infection is the job of immune components like antibodies and white blood cells. Iron storage is managed by proteins such as ferritin and transferrin, not albumin.