This chapter is about the functions involved in the cardiovascular system (functions of the heart and blood vessels), the haematological and immunological systems (functions of blood production and immunity), and the respiratory system (functions of respiration and exercise tolerance).
Lower livel:
b429 Functions of the cardiovascular system, other specified and unspecified
b439 Functions of the haematological and immunological systems, other specified and unspecified
b449 Functions of the respiratory system, other specified and unspecified