Glossary of Physiology Terms

Physiology

Physiology is the study of how living systems function. The scope of physiological studies ranges from the subcellular level (molecules and organelles) all the way to the level of the whole organism and how organisms adapt to vastly different environmental conditions such as hot, cold, dry, humid, or high altitude.

What is Physiology?

Plasma

Plasma is the fluid portion of whole blood, which makes up about 40% to 60% of the total volume of whole blood. Plasma has a light yellow color and is generally obtained by separating the fluid portion from the blood formed elements through sedimentation or centrifugation. Plasma contains mostly water and, in addition, minerals, nutrients, proteins, hormones, and gases (oxygen and carbon dioxide). Unlike serum, in which fibrinogen and other clotting factors have been removed by coagulation, fibrinogen and other clotting factors remain present in plasma.

Plasma is one the main fluid compartments of the human body, making up nearly 10% of the total volume of body fluids. Plasma makes up the intravascular fluid compartment; itself a subcompartment of the extracellular fluid compartment.