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.
Mask and Headstrap New Filters ... foil with authentic czech writing ... Lycra Quick Dry Breathable Well Full Face Mask Soft Skin-friendly Balaclava Hood For Motorcycle Ski Cycling and other Outdoor Sports -For Women and Men. by Rosea. 5 out of 5 stars 1.