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.
Nasal cannulas and face masks are used to deliver oxygen to people who don't otherwise get enough of it. They are commonly used to provide relief to people with respiratory disorders. A nasal cannula consists of a flexible tube that is placed under the nose. The tube includes two prongs that go inside the nostrils.