L18A
42.1 Circylatory systems link exchange surfaces with cells throughout the body
42.2 Coordinated cycle of heart cintraction drive double circulation in mammals
42.3 Patterns of blood pressure and flow reflect the structure and arrangement of blood vessels
42.4 Blood components function in exchange , trandport, and defense
42.5 Gas exchange occurs across specialized repiratory surfaces
42.6 Breathing ventilates the lungs
42.7 Adaptations for gas exchange include pigments that blind and transport gases