Compact bone is dense bone tissue found on the outside of a bone. Basically, in kindergarten when you drew skeletons, you were drawing compact bone. Compact bone is enclosed, except where it's covered by articular cartilage, and is covered by the periosteum.
medullary cavity: The medullary cavity, also known as the marrow cavity, is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored. diaphysis: The central shaft of any long bone.
Spongy (Cancellous) Bone. Like compact bone, spongy bone, also known as cancellous bone, contains osteocytes housed in lacunae, but they are not arranged in concentric circles. Instead, the lacunae and osteocytes are found in a lattice-like network of matrix spikes called trabeculae (singular = trabecula) (Figure 6.3.
Spongy bone consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow. The canaliculi connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply.
There are two types of bone tissue: compact and spongy. The names imply that the two types differ in density, or how tightly the tissue is packed together. There are three types of cells that contribute to bone homeostasis.
Bone is a connective tissue containing cells, fibers and ground substance. There are many functions in the body in which the bone participates, such as storing minerals, providing internal support, protecting vital organs, enabling movement, and providing attachment sites for muscles and tendons.
Besides cortical and spongy bone tissues, bones contain several other tissues, including blood vessels and nerves. In addition, bones contain bone marrow and periosteum. You can see these tissues in Figure 14.4.
Bone marrow is found in the center of most bones and has many blood vessels. There are two types of bone marrow: red and yellow. Red marrow contains blood stem cells that can become red blood cells, white blood cells, or platelets. Yellow marrow is made mostly of fat.
Epithelial tissue provides a covering (skin, the linings of the various passages inside the body).
Radiographic Positioning
| A | B |
|---|
| which aspect of a long bone is responsible for production of red blood cells? | Spongy |
| Which aspect of long bones are essential for growth repar and nutrition | Periosteum |
| what is the primary growth center of a long bone? | Diaphysis |
| what is the secondary growth center of a long bone? | Epiphysis |
Bone is resistant to bending, twisting, compression and stretch. It is hard, because it is calcified, and the collagen fibres help the bone to resist tensile stresses. If you dissolve away the calcium salts of bone, then the bone becomes rubbery because of the collagen fibres which are left behind.
