Why do we consider blood as a connective tissue?
Blood is considered a connective tissue because it consists of a fluid matrix called plasma along with formed elements. The plasma constitutes nearly 55 per cent of the blood and serves as the matrix in which the formed elements are suspended.
The formed elements include red blood cells (RBCs), white blood cells (WBCs) and platelets. Like other connective tissues, blood has cells embedded in a matrix. Blood also helps in connecting different parts of the body by transporting nutrients, gases, hormones and other substances. The exchange of nutrients and gases between blood and cells occurs through the tissue fluid (lymph), which is derived from blood.
Explanation
The textbook explicitly states that 'Blood is a special connective tissue consisting of a fluid matrix, plasma, and formed elements.' This definition highlights the two key components that qualify blood as a connective tissue: (1) the fluid matrix (plasma) and (2) the formed elements (RBCs, WBCs, platelets). Additionally, the context mentions that blood is a body fluid used for transport and that exchange of substances occurs through tissue fluid, emphasizing its connecting role in the body.