Structure of Blood Components Blood is a specialized connective tissue that consists of two main components: 1. Plasma (55% of blood volume) 2. Formed Elements (45% of blood volume) Red Blood Cells (RBCs/Erythrocytes): Detailed Overview Red blood cells (RBCs), also known as erythrocytes, are the most abundant cells in the blood. Their primary function is to transport oxygen from the lungs to the tissues and carbon dioxide from the tissues