Term
| Functions of the Skeletal System |
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Definition
Support - for the body and soft organs
Protection - for brain, spinal cord, and vital organs
Movement - levers for muscle action
Storage - minerals (calcium and phosphorus) and growth factors
Blood cell formation - (hematopoiesis) in marrow cavities
Triglyceride (energy) storage- in bone cavities
Hormone production: - Osteocalcin |
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Definition
- contain no blood vessels or nerves
- dense connective tissue girdle of perichondrium contains blood vessels for nutrient delivery to cartilage |
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Definition
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Definition
Provide support, flexibility, and resilience
Most abundant type |
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Definition
| Similar to hyaline cartilages, but contain elastic fibers |
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Definition
| Collagen fibers—have great tensile strength |
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Term
| Appositional growth of cartilage |
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Definition
| Cells secrete matrix against the external face of existing cartilage |
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Term
| Interstitial growth of cartilage |
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Definition
| Chondrocytes divide and secrete new matrix, expanding cartilage from within |
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Term
| Calcification of cartilage |
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Definition
| occurs during normal bone growth & old age |
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Term
| why is cartilage not bone? |
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Definition
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Definition
| Longer than they are wide |
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Definition
Cube-shaped bones (in wrist and ankle)
Sesamoid bones (within tendons, e.g., patella) |
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Definition
| Thin, flat, slightly curved |
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Definition
| Complicated shapes, sutural bones |
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Definition
Compact bone collar surrounds medullary (marrow) cavity
Medullary cavity in adults contains fat (yellow marrow) |
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Definition
Expanded ends
Spongy bone interior
Epiphyseal line (remnant of growth plate)
Articular (hyaline) cartilage on joint surfaces |
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Term
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Definition
Outer fibrous layer
Inner osteogenic layer
Osteoblasts (bone-forming cells)
Osteoclasts (bone-destroying cells)
Osteogenic cells (stem cells)
Nerve fibers, nutrient blood vessels, and lymphatic vessels enter the bone via nutrient foramina
Secured to underlying bone by Sharpey’s fibers |
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Definition
Delicate membrane on internal surfaces of bone
Also contains osteoblasts and osteoclasts |
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Definition
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Definition
| bone-destroying cells that resorb bone matrix |
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| Osteon (compact bone not spongey) |
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Definition
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Definition
| stem cells in periosteum and endosteum that give rise to osteoblasts |
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Definition
| Medullary cavity in adults contains fat (yellow marrow) |
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Term
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Definition
Trabecular cavities of the heads of the femur and humerus
Trabecular cavities of the diploë of flat bones
Red marrow of newborn infants
Medullary cavities and all spaces in spongy bone |
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Term
| Ostification of Bone Stages |
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Definition
bone tissue formation*
Bone formation—begins in the 2nd month of development
Postnatal bone growth—until early adulthood
Bone remodeling and repair—lifelong |
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Term
| inorganic vs organic w/respect to calcium cells, osteoid -- short answer |
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Definition
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Term
| intramembraneous ossification |
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Definition
(Fig 6-8)
Membrane bone develops from fibrous membrane
Forms flat bones, e.g. clavicles and cranial bones |
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Term
| endochondral ossification |
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Definition
(Fig 6-9)
Cartilage (endochondral) bone forms by replacing hyaline cartilage
Forms most of the rest of the skeleton |
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Definition
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Term
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Definition
| thickness and remodeling of all bones by osteoblasts and osteoclasts on bone surfaces |
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Term
| What controls continual remodeling of bone? |
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Definition
Hormonal mechanisms that maintain calcium homeostasis in the blood
Mechanical and gravitational forces |
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Term
| what regulates bone growth (hormones PTH, Calcium, etc) |
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Definition
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Term
| Wolf’s law with mechanical stress |
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Definition
| A bone grows or remodels in response to forces or demands placed upon it |
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Term
| What classifies bone fractures? |
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Definition
1. Position of bone ends after fracture
2. Completeness of the break
3. Whether or not the bone ends penetrate the skin |
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Term
| repairing fractures (4 steps) |
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Definition
1. Hematoma forms
Torn blood vessels hemorrhage
Clot (hematoma) forms
Site becomes swollen, painful, and inflamed
2. Fibrocartilaginous callus forms
Phagocytic cells clear debris
Osteoblasts begin forming spongy bone within 1 week
Fibroblasts secrete collagen fibers to connect bone ends
Mass of repair tissue now called fibrocartilaginous callus
3. Bony callus formation
New trabeculae form a bony (hard) callus
Bony callus formation continues until firm union is formed in ~2 months
4. Bone remodeling
In response to mechanical stressors over several months
Final structure resembles original |
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Term
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Definition
Loss of bone mass—osteoclasts (eating bone) working harder than osteoblasts (forming bone)
Spongy bone of spine and neck of femur become most susceptible to fracture
Risk factors
Lack of estrogen, calcium or vitamin D; petite body form; immobility; low levels of TSH; diabetes mellitus |
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Term
| heterotrophic bone formation |
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Definition
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Term
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Definition
| cartilage is being stimulated to forms & elongate |
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Definition
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Term
| Calcium is necessary for: |
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Definition
Transmission of nerve impulses
Muscle contraction
Blood coagulation
Secretion by glands and nerve cells
Cell division |
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Term
| Observations supporting Wolff’s law: |
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Definition
Handedness (right or left handed) results in bone of one upper limb being thicker and stronger
Curved bones are thickest where they are most likely to buckle
Trabeculae form along lines of stress
Large, bony projections occur where heavy, active muscles attach |
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Term
| Nondisplaced vs. Displaced Fracture |
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Definition
Nondisplaced—ends retain normal position
Displaced—ends out of normal alignment |
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Term
| Complete vs. Incomplete Fracture |
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Definition
Complete—broken all the way through
Incomplete—not broken all the way through |
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Definition
Compound (open)—bone ends penetrate the skin
Simple (closed)—bone ends do not penetrate the skin |
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Term
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Definition
Calcium salts not deposited
Rickets (childhood disease) causes bowed legs and other bone deformities
Cause: vitamin D deficiency or insufficient dietary calcium |
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Definition
Excessive and haphazard bone formation and breakdown, usually in spine, pelvis, femur, or skull
Unknown cause (possibly viral) |
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Definition
bone fragments into three or more pieces
*common in aged whose bones are more brittle |
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Definition
bone is crushed
*common in porous bones (osteoporosis) subjected to extreme trauma |
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Definition
Ragged break occurs when excessive twisting forces are applied to bone
*common sports injury |
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Definition
epiphysis separates from diaphysis along the epiphyseal plate
*tends to occur where cartilage cells are dying and calcification of the matrix is occurring |
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Definition
broken bone portion is pressed inward
*skull fracture |
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Term
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Definition
bone breaks incompletely like a green twig; one side breaks the other bends
*common in children whose bones have a relatively organic matrix and are more flexible than adults |
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Term
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Definition
| occurs at the ankle and effects both bones of the leg |
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Definition
| break a bone shaft across its long axis |
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Definition
| produce new and abnormal bone arrangements |
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Definition
| retains normal alignment of bones or fragments |
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Definition
| a break in the distal portion of the radius; typically occurs as a result of reaching out to cushion a fall |
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