State the functions of the components of blood: (a) red blood cells – oxygen transport (b) white blood cells – antibody production by lymphocytes and engulfing pathogens by phagocytes (c) platelets – clotting by converting soluble fibrinogen to insoluble fibrin to prevent blood loss and the entry of pathogens (d) plasma – transport, limited to: blood cells, ions, glucose, amino acids, hormones, carbon dioxide, urea, vitamins and plasma proteins

Describe the control of blood glucose concentration by the liver and pancreas and the roles of insulin and glucagon