Osteocyte
A bone cell trapped within the bone matrix. Maintains the matrix
while trapped.
Osteoblast
A bone cell that produces bone matrix. Becomes an osteocyte after it
is trapped in the matrix.
Osteoclast
A bone cell that dissolves and removes bone matrix from bone
Lamella
Layers of bone matrix
Canaliculus
Microscopic tunnels running through lamellae from one osteocyte to
another. Occupied by the long processes of the osteocytes where they
contact one another.
Lacuna
The chamber in the bone matrix where the osteocyte resides. Made by
the osteoblasts as they deposit bone matrix around themselves,
trapping themselves in the matrix.
Cancellous bone
Sometimes called spongy bone. An open network of bone matrix shaped
into trabeculae (branches) leaving open space for the placement of red
bone marrow. The internal structure of most bones.
Compact bone
Solid layers of bone matrix in three types of layering with the
osteon as the basic unit of structure. Typically found on the surfaces
of all bones.
Osteon
The structural unit of compact bone. Circular layers of bone matrix
surrounding a central canal.
Concentric lamellae
Layers of bone matrix surrounding the central canal and within the osteon.
Interstitial lamellae
Layers of bone matrix between the osteons of compact bone
Circumfrential lamellae
Layers of bone matrix on the surface of compact bone and on the
surface of the bone itself. The outermost of the outermost layers of
the bone.
Central canal
A vertical canal or tube through the center of an osteon in compact bone.
peripheral canal
A horizontal canal within compact bone
Trabecula
A branch of bone tissue in cancellous bone
Calcium and phosphate
Minerals imbedded in the ground substance of bone matrix to make the
bone hard.
Ground substance
The rubbery matrix produced by osteoblasts and chondroblasts for the
structure of their tissue.
Epiphysis
Knobby end of a long bone
Diaphysis
Shaft of a long bone
Medullary cavity
Hollow cavity in the diaphysis of a long bone
Endosteum
Membrane lining the medullary cavity
Periosteum
Dense Fibrous membrane covering the surfaces of all bones
Epiphyseal plates
Growth plates in a long bone. One at each epiphysis of a long bone.