Plasma Oncotic Pressure is Caused Primarily By

Question

Plasma oncotic pressure is caused primarily by
A) blood pressure.
B) plasma proteins, especially albumin.
C) lymph.
D) electrolytes such as sodium and chloride.

Accepted Answer

Plasma oncotic pressure is mainly caused by plasma proteins, particularly albumin. These proteins create an osmotic force that draws fluid from the interstitial spaces into the vascular compartment. Blood pressure (A) affects hydrostatic pressure, not oncotic pressure. Lymph (C) plays a role in fluid balance, but it does not contribute significantly to plasma oncotic pressure. Electrolytes (D) also affect fluid balance but not oncotic pressure.