|Arterioles and venules are linked by tiny ____.
|Inhaled asbestos and tobacco smoke are non-radioactive ____.
|The ____ are the two upper chambers of the heart.
|Your two ____ take in oxygen and expel carbon dioxide.
|Proteins are polymers (chains) of ____.
|Insulin and glucagon are ____ that regulate blood glucose.
|Arteries, veins, and capillaries are blood ____.
|The various pigments that give skin and hair color are ____.