Cancellous bone. False-colour scanning electron micrograph of trabeculae in cancellous (spongy) bone tissue. Bone tissue is divided into compact & cancellous. The latter fills the interior of bones & the cavities between the trabeculae are occupied by bone marrow. Trabeculae are thin & composed of irregular lamellae of bone with lacunae containing osteocytes. Some of these lacunae are visible as tiny orange holes at upper centre. Osteblasts are the cells responsible for bone formation. Once they cease activity & become embedded in bone matrix they are called osteocytes. Magnification: x40 at 6x7cm size. Magnification: x40 at 4x5 inch size.