| A | B |
|---|
| calcification the mineralization | or hardening process of the tissue |
| flat bone thin curved plates | such as most cranial bones |
| long bones in the limbs | most important bones in body movement |
| short bones 30 in wrists and ankles; roughly equal in length | make fairly limited gliding movements |
| irregular bones don't fit a category - such as vertebrae | sphenoid & ethnoid bones of the skull |
| compact bone the outer shell of dense | white osseous tissue (also called dense or lamellar bone) |
| spongy bone (cancellous) at ends of bone | more loosely organized form of osseous tissue; also occurs at inside of the shaft and in the middle of most flat |
| endosteum thin layer of reticular connective tissue which lines the internal marrow cavity | covers all the honeycombed surfaces of spongy bone and liens the canal system in compact bone |
| epiphyseal line in adult bones | it marks where the epiphyseal plate used to be |
| osteogenic (osteoprogenitor) cells stem cells that develop from embryonic mesenchymal cells and give rise to most other bone cell types. found in endosteum | inner layer of periosteum and in central canals. they constantly multiply and some turn into osteoblasts |
| osteoblasts boneforming cells. Roughly cuboid and line up in single layer on bone surface under endosteum and periosteum; nonmitotic | so can only be formed by new osteogenic cells. They synthesize the soft organic matter of the bone matrix |
| osteocytes former osteoblasts that have become trapped in the matrix they deposted. Have tiny fingerlike cytoplasmic processes that reach into the canaliculi to contact processes from nearby osteocytes. Have many functions - resorb or deposit bone matris | strain sensors. |
| hydroxyapatite inorganic matter that composes about 85% of the bone matrix | mostly crystallized calcium phosphate salt |
| composite a combination of two basic structural materials | a ceramic (hydroxyapatite and other minerals) polymer (collagen). |
| red bone marrow (myeloid tissue) tissue the fills the marrow cavity of nearly every bone in a child; produces blood cells.in adults it is limited to skull | vertebrae |
| secondary ossification center when chondrocyte enlargement and death happen in the epiphysis of the model also. happens in only one epiphysis in metacarpal bones | but on both ends of the long bones |
| zone of reserve cartilage farthest from marrow cavity | with cartilage that shows no sign of transforming into bone yet |
| zone of cell proliferation closer to marrow cavity | where chondrocytes multiply and form long columns of flat lacunae |
| zone of bone deposition the walls between the lacunae break down in each column and the chondrocytes die | converting each column into a long channel immediately invaded by blood vessels and marrow from the marrow cavity. Osteoblasts line up alone the channel walls and begin depositing concentric lamellae of matrix and osteoclasts dissolve remaining cartilage. |
| interstitial growth cartilage growth from within | by the multiplication of chondrocytes and deposition of new matrix in the interior |
| ectopic ossification abnormal calcification of tissues in lungs | brain |
| calculus a calcified mass in a normally soft organ | like the lungs |
| calcium homeostasis maintenance of calcium levels based on balance of diet | urinary & fecal losses and exchanges witin osseous tissue. Regulated by 3 hormones: calcitriol |
| calcitriol vitamin D produced by sequential action of skin | liver and kidneys |
| calcitonin secreted by C cells (clear cells) of thyroid gland | when Ca concentration is too high. lowers Ca by osteoclast inhibition (making osteoclasts release less Ca from skeleton) and osteoblast stimulation (increase activity of osteoblasts |
| Parathyroid Hormone (PTH) secreted by parathyroid glands which are behind thyroid and release PTH when Ca levels are low. Binds to rceptors on osteoblasts | promotes Ca resorption in bones |
| pathological fracture break in a bone weakened by a disease | usually caused by a stress that would not normally fracture a bone |
| greenstick fracture bone incompletely broken on one side | only bent on the other |
| open reduction surgical insertion of plates | screw or pins to realign the fragments |
| physiological buffer system that stabilizes pH by controlling body's output of acids | bases of CO2. |
| chemical buffer substand that binds H+ and removes it from solution as its concentration begins to rise | or releases H+ into solution as concentration falls |
