What is the liquid portion of blood called?

The liquid portion of blood is called plasma. Plasma is a yellowish fluid that makes up about 55% of total blood volume. It serves several critical functions, including transporting nutrients, hormones, proteins, and waste products throughout the body. It also plays a significant role in maintaining blood pressure and regulating body temperature.

Plasma contains not only water but also proteins, electrolytes, gases, and waste products. Among its many components, plasma proteins such as albumin and globulins are vital for various bodily functions, including immune response and maintaining osmotic pressure.

In contrast, serum refers to the liquid that remains after blood has clotted and does not contain clotting factors, while hemoglobin is the protein in red blood cells responsible for oxygen transport. Platelets are small cell fragments that play a crucial role in blood clotting but do not contribute to the liquid component of blood. Understanding plasma and its role in the circulatory system is essential for anyone studying emergency medical services or related fields.