Which component circulates through the cardiovascular system along with blood cells?

The correct answer is plasma, which is the liquid component of blood that circulates alongside blood cells in the cardiovascular system. Plasma is primarily made up of water, but it also contains essential proteins, electrolytes, hormones, and waste products. This fluid serves several critical functions, including transporting nutrients, electrolytes, and hormones throughout the body, maintaining blood pressure and volume, and facilitating the removal of waste products from metabolic processes.

In contrast, tissue refers to a group of cells working together to perform a specific function and is not a component of the circulatory system. Serum is derived from plasma after coagulation and lacks clotting factors, meaning it is not present in the blood while circulating. Lymph is a fluid that is part of the lymphatic system, which plays a role in immune function and does not circulate in the same manner as blood within the cardiovascular system.