What is plasma?

Plasma is indeed the liquid portion of blood, constituting about 55% of its overall volume. It serves several vital functions, including transporting nutrients, hormones, and proteins to the parts of the body that need them. Plasma is also significant for maintaining blood pressure and regulating body temperature. This liquid component is primarily composed of water but also contains a mix of proteins, electrolytes, and waste products that help in various physiological processes. The components that make up plasma are crucial for maintaining homeostasis and ensuring the proper functioning of the circulatory system.

The other options, while related to blood, describe different elements or aspects that do not accurately define plasma. The solid component of blood is primarily made up of red blood cells, white blood cells, and platelets. The gas released by blood cells typically refers to the exchange of carbon dioxide and oxygen, but this is not what plasma is. Likewise, cellular waste in blood pertains to metabolic waste products, which are transported by plasma but do not define it. Therefore, defining plasma solely as the liquid part of blood highlights its essential role in circulating various substances throughout the body.