Blood plasma is the yellowish liquid portion of blood, which carries nutrients, hormones, and waste products throughout the body. It is composed of proteins, electrolytes, and other important components, making it vital for maintaining the body's overall health and function. There are several synonym words that can be used to refer to blood plasma, such as serum, lymphatic fluid, extracellular fluid, and interstitial fluid. Serum is similar to blood plasma but lacks fibrinogen, while lymphatic fluid is a mixture of blood plasma and lymph. Extracellular fluid refers to any bodily fluid outside the cells, whereas interstitial fluid is the fluid surrounding the cells. These different synonyms for blood plasma are useful for describing its composition and relation to other bodily fluids.