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39 Cards in this Set
- Front
- Back
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Axial Skeleton |
-Skull -Vertebrae (spine) -Ribcage |
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Appendicular Skeleton |
-Upper & lower limbs -Associated girdles (that attach limbs to axial skeleton) |
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Bone structure |
Compact Bone & Spongy Bone |
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Compact Bone |
Dense, outer layer (adapted to support weight & withstand tension stress) |
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Spongy bone |
Made up of TRABECULAE that are surrounded by spaces filled with red & yellow marrow Yellow - contains large % of fatty tissue..can revert to red when young, changes to yellow Red - in emergency
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Diaphysis |
Compact bone surrounding a medullary cavity Shaft of LONG BONE
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Epiphysis |
Compact outer, spongy bone inner Bone ends of LONG BONE
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Articular cartilage |
(Hyaline) - lines the bone ends (articular surfaces) makes friction almost impossible |
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Epiphyseal plate |
In growing children and adolescents Ossifies to end growth length |
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The plate |
Cartilage that grows to give the bone length (allows the diaphysis to increase length) |
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The most important stimulus for plate growth is |
The growth hormone |
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Periosteum |
Double-layered membrane covers the bone (except at articular cartilage) |
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The inner osteogenic layer of the periosteum consists of... |
Osteoblasts and Osteoclasts |
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Cells of bone tissue: |
-Osteogenic Cells -Osteoblasts -Osteocytes -Osteoclasts |
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Lie in inner layer of periosteum and endosteum |
Osteogenic Cells |
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Cells that secrete bone matrix When completely surrounded by matrix, turn to |
Osteoblasts Osteocytes |
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Monitor the matrix, sense stress and communicate |
Osteocytes |
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Resorb bone, break it down They originate from hematopoietic cells that make macrophages Has rich supply of blood and neural tissue |
Osteoclasts |
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The bones are constantly undergoing ___________ for various reasons |
Resorption |
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The structural unit of compact bone is the _________ |
Osteon |
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Formed by concentric lamellar tubes Each surrounds a haversian aka central canal |
Osteon |
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Contains blood vessels and nerve supply in an osteon |
Haversian aka Central Canal |
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Cavities within bone matrix, occupied by osteocytes |
Lacunae |
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Tiny canals that exit the lacunae Contain processes of osteocytes...they communicate with one another |
Canaliculi |
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Spongy bone consists of _____________ as the main structural unit They are aligned along lines of stress |
Trabeculae |
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CHEMICAL COMPOSITION OF BONES |
1/3 Cells, fibers (collagen) {bend} |
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CHEMICAL COMPOSITION OF BONES Inorganic |
2/3 Mostly hydroxyapatite {strength} |
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Mineral salts - calcium, phosphates Tiny crystals to give hardness |
Hydroxyapatite |
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Process of bone formation |
Osteogenesis aka Ossification |
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Hyaline cartilage bones are used as models for all of the long bones in the fetus |
Endochondral ossification |
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Forms cranial bones, clavicles These develop within fibrous tissue membranes that will ossify |
Intramembranous ossification |
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During infancy & youth, _________________ is exclusively done through interstitial growth at the epiphyseal plate The osteogenic cells proliferate, pushing the epiphysis away from the diaphysis |
(Bone) Growth in Length |
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From osteoblasts beneath periosteum |
(Bone) Growth in width aka Appositional Growth |
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Hormones that regulate bone growth |
Growth hormone Thyroid hormone Calcitonin Parathyroid hormone |
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Single most important factor of epiphyseal plate growth |
Growth H. |
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Makes sure growth is proportional |
Thyroid H. |
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Tends to decrease blood calcium levels |
Calcitonin |
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Increases osteoclastic activity to increase blood Ca ++ |
Parathyroid H. |
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Holds that a bone grows or remodels in response to demands placed on it |
Wolff's Law |
