'Osseous tissue', or 'bone tissue' is the major structural and supportive
connective tissue of the body. Osseous tissue forms the rigid part of the
bone organs that make up the
skeletal system.
Formation
The bone tissue is a mineralized connective tissue. Bone-forming cells called
osteoblasts deposit a matrix of
collagen, but they also release calcium, magnesium, and phosphate ions, which chemically combine and harden within the matrix into the mineral
hydroxyapatite. The combination of hard mineral and flexible collagen makes bone harder than
cartilage without being brittle. The microscopic structure of mammalian bone consists of repeating units called
Haversian systems. Each system has concentric layers of mineralized matrix, which are deposited around a central canal containing blood vessels and nerves that service the bone.
Types
There are two types of osseous tissue,
compact and
spongy. Compact bone forms the extremely hard exterior while spongy bone fills the hollow interior. The tissues are biologically identical; the difference is in how the microstructure is arranged.
Functions of osseous tissue
Osseous tissue performs numerous functions including:
Directly:
★ Support for
muscles,
organs, and soft tissues.
★ Leverage and movement.
★ Protection of
vital organs. e.g. the heart
★
Calcium phosphate storage.
Indirectly:
★
Hemopoiesis - formation of blood cells (more correctly this is performed by the
marrow interspersed within the
spongy interior.
Osseous tissue versus bones
Bone tissue is different from bones themselves - bones are organs made up of bone tissue as well as marrow, blood vessels, epithelium and nerves, while bone tissue refers specifically to the mineral matrix that form the rigid sections of the organ.
See also
★
Periosteum
★
Bone healing
★
Osseointegration