In your body, you have only two types of bone tissue: cortical and cancellous bone. In this lesson, we will learn about the structure and function of cancellous bone, which plays a crucial role in producing blood cells and stem cells and is the primary tissue affected by osteoporosis.
balaclava (plural balaclavas) 1  A warm cap shielding the neck and head, often made out of wool. ( 2 chiefly Canada) A ski mask with holes for the eyes and, sometimes, the nose and mouth, which may be rolled up and worn like a toque or pulled over the face for greater protection.
Face Masks, Ski Masks and Balaclava. A great snow hat like a neoprene face mask or ski mask is a must have for skiers and snowboarders this winter. We carry both of half face mask and full face mask. You will also find balaclava mask, ski hats with ear flaps and many more here. 108 Item(s)