While much information can be gleaned by testing the blood itself (drawn from a vein by phlebotomy), it is sometimes necessary to examine the source of the blood cells in the bone marrow to obtain more information on hematopoiesis; this is the role of bone marrow aspiration and biopsy.
From Wikipedia, the free encyclopedia. The wheel bug (Arilus cristatus), in the family Reduviidae, is one of the largest terrestrial true bugs in North America, being up to 1.5 inches (38 mm) in length. A characteristic structure is the wheel-shaped pronotal armor.
A cogwheel is a mechanical part used in machine assemblies. It is also known as a gear and is an essential part of many common devices, including automotive transmissions. The body of the gear rotates just as a wheel does, and its outer edge is lined with protuberances called teeth or cogs; hence the name cogwheel.