Term
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Definition
1. Support: for entire body; endoskeleton
2. Protection: ex- skull protects brain
3. Movement: skeletal muscles utilize
4. Mineral Storage: calcium/phosphate used in various chemical reactions
5. Blood Cell Formation: (Hematopoiesis) in bone marrow |
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Term
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Definition
Outer part; smooth, continuous, dense, solid bone
Made of structural unit, osteons; Contains lamellae, haversian canal, volkmann canal, osteocytes, lacunae, caniculi, interstitial lamellae, and ncircumferential lamellae. |
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Definition
| Typically interior; not as smooth; arranged in narrow, irregular bars (lattice); light weight; no osteons |
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Definition
| In compact bone; concentric layers that form osteon |
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Definition
| In compact bone; central canal of osteon; filled with blood vessels (for nourishment) and nerve fibers |
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Definition
| In compact bone; run perpendicular (transverse)to H.C; bring blood circulation in from exterior bone to interior. |
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Definition
| In compact bone; mature bone cells; sits in lacunae |
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Definition
| In compact bone; cavities that contain osteocytes |
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Definition
| In compact bone; small canals that conect lacunae to Haversian canal; allows for exchange of materials from cells and blood supply |
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Definition
| In compact bone; between osteons; layers of bone to fill space and maintain integrity |
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Definition
| Encircle compact bone; outside of osteon clusters and just deep to periosteum |
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Term
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Definition
Two Components:
1) Diaphysis: shaft, in middle, compact bone and medullary cavity
2) Epiphysis: Bulbous ends; Compact bone surrounds spongy bone
-Articular cartilage: provides smooth surface at joint
-Epiphyseal line: old growth plate
Membranes of Long Bone:
1) Periosteum: outside; contains osteogenic cells
2) Endosteum: inside linging covering medullary cavity and spongy bone; also contains osteogenic cells
ex: humerus, ulna, femur |
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Term
| Short, Irregular, and Flat Bones |
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Definition
All consist of a compact bone sandwiching a thin layer of spongy bone (diploe); has periosteum and endosteum
ex: hand bones, sternum, & vertebra |
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Term
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Definition
Tissue in bone that develops blood (Red Marrow); within trabecular cavities of select long bones and diploe of flat bones;
In infants, medullary cavity also has red marrow, but it turns to fat by adulthood (then yellow marrow) |
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Term
| Bone Cell Chemical Composition |
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Definition
1) Osteoblasts: bone forming cells that secrete bone matrix (mitotic); matrix calcification
2) Osteoclasts: bone destroying cells; phagocytic; destroys matrix, releasing calcium and phosphate into blood stream
3) Osteocyte: mature bone cell; former osteoblast; not mitotic; maintains bone matrix
4) Osteogenic cells: stem cells; mitotic found in periosteum and endosteum; can differentiate into osteoblasts |
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Term
| Bone Matrix Chemical Composition |
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Definition
Ground Substance: osteoids that are secreted by osteoblasts
1) Proteoglycans: large proteins and carb groups
2) Glycoproteins: smaller prteins and carb groups
3) Hydroxypatites: calcium phosphate
Fibers: Collagen; low water content compared to cartilage, so very dense |
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Term
| Compact bone periphery/Spongy Bone centrally function |
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Definition
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Term
| Calcium phosphates function |
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Definition
| calcium and phosphate stores |
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Term
| Osteoclasts, 'blasts, and osteogenetic cell function |
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Definition
| Break down to release minerals, blasts build up bone, osteogenic divides and differentiates cells into blasts to build |
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Definition
| Space for blood cell development |
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Term
| Intramembraneous Ossification |
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Definition
Osteogenesis within membrane; involves messenchyme(embryonic connective tissue)
-Typically occurs in flat bones(skull)
1. Osteoblasts form
2. Osteoblasts secrete matrix which is then calcified
3. Bone differentiates/becomes woven
4. Lamellar bone replaces woven bone |
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Term
| Endochondral Ossification |
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Definition
Osteogenesis in cartilage;
-Typically occurs in long bones
1. Osteobblasts form bone collar around cartilage
2. Central cartilage calcifies and cavity develops
3. Periosteal bud invades (artery, vein, and nerve fibers); brings osteoclasts
4. Diaphysis elongates, medullary cavity forms, secondary ossification begins at epiphyseal regions
5. Epiphyses ossify, leaving cartilage within the ephiphyseal plate and at articular surface of bone |
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Term
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Definition
Cartilage template replaced by bone;
Length:
-Cartilage grows at distal epiphysis
-Cartilage grows at epiphyseal plate
- Osteoblasts multiply-secrete matrix, osteocytes replace cartilage
-Osteoclasts carve medulalary cavity
Appositional Growth: Width
-Periosteal Osteoblast lays down bone and secretes matrix to thicken |
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Term
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Definition
-Growth hormone: secreted from anterior pituitary and releases Somatomedins which promote cartilage growth at epiphyseal plate.
-Thyroid Hormone: works with GH's
-Androgenic and estrogenic steroids (testosterone/estrogen): promote epiphyseal plate closure at puberty |
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Term
| Remodeling Hormones in Bone |
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Definition
5-7% turnover per week; occurs throughout lifetime; strengthens bones for activites
- Remodeling Units: continually synthesize and remove bone
-Parathyroid hormones: increase osteoclast activity for blood reabsorption; released when blood calcium levels low
-Calcitonin: inhibits osteoclasts activity; released when blood calcium levels high
- Response to mechanical stress: Wolff's law- bone grows and remodels in response to mechanical demand (muscle pull and load); Accounts for: asymmetrical limb thickness, bone thickness at curved areas, enhanced bony projections at area of muscle attachment, etc...
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