Final answer:
The transport of metabolic wastes, oxygen, and hormones are distribution functions of blood, whereas maintaining blood volume with salts is not a direct function of blood but a regulatory process of the body.
Step-by-step explanation:
The function that is not a distribution function of blood is transport of salts to maintain blood volume. The primary functions of blood include the transport of metabolic wastes from cells, delivery of oxygen to body cells, and transport of hormones to their target organs. Blood is a connective tissue comprising cellular elements such as red blood cells (RBCs), white blood cells (WBCs), and platelets, and an extracellular matrix known as plasma, allowing these elements to circulate in the cardiovascular system. Blood's primary function is to deliver oxygen and nutrients to and remove wastes from body cells, including defense, distribution of heat, and maintenance of homeostasis.
Blood also picks up cellular wastes and byproducts, transporting them to various organs for removal, and carries hormones released by endocrine glands to distant target cells. However, the transport of salts to maintain blood volume is not a function of blood itself but rather the regulatory function of various organs and systems in the body that act to maintain homeostasis.