Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

Bone/CartilaginousTissueBone, or osseous tissue, is a form of dense connective tissue in which the intercellular substance,or matrix, is infiltrated with calcium salts. It differs from cartilage in that bone is a vascular tissuepermeated with canaliculi. The canaliculi are tiny canals that connect the lacunae (in which bonecells lie) with each other and serve as a transport system (Haversian system) between the bloodcapillaries and the bone cells. Tissue fluid in the canaliculi diffuses oxygen and nutrient material fromthe blood to the bone cells and carries their waste material back to the circulatory system. Thus thebone cells (osteocytes) may remain alive although surrounded by calcified intercellular substance(bone matrix). No bone cell is more than 0.1 mm from a blood capillary.In contrast, cartilage is nonvascular connective tissue. Its cells (chondrocytes) are nourished bymeans of blood vessels in the outer layer ofperichondrium which covers the surface of the cartilage.There are three types of cartilage:• Hyaline cartilage, the most abundant, may become calcified and replaced by bone.However, much of it remains uncalcified as part of the ears, nose, larynx, trachea,and larger bronchi, and as a covering of the articulating 1 bones in freely movingjoints where it has a cushioning effect.• Elastic cartilage is rare; it occurs primarily in the external ear and in the epiglottis.• Fibrocartilage (fibrous cartilage) is found in the areas where tendons insert intobone.Figure 59. OSSEOUS TISSUEFigure 60. HYALINE CARTILAGE: _." " "...- ...'.::...i• • • .... " . . . . _" _-" : ". 'u_z_A.•.:''." " • _- ."_:: _ ...'._._ " . ".'. ',Chondrocyte8larticulation--the place of union or junction between two or more bones.347