skeletal Flashcards
skeletal functions
provides framework, protects soft internal tissues, lever for movement, reservoir for minerals, red blood cell production and energy storage
tendon
connects muscle to bone
ligaments
connect bone to bone
Epiphyseal plate
growth plate
hyaline cartilage
becomes epiphyseal line in adults
Medullary cavity
Filled with red marrow as children and turns to yellow as adults
Endosteum
Lines medullary cavity
Osteoprogenitor cells, osteoblasts, osteoclasts
Periosteum
CT wrapping of bones
fibrous and osteogenic
Fibrous layer
Anchors vessels and nerves to bone surface
Tendon/ligament attachment
Osteogenic layer
Osteoprogenitor cells,
osteoblasts, osteoclasts
Articular cartilage
Thin layer of hyaline that covers the joint. reduces friction and absorbs shock
Nutrient foramen
blood and nerves penetrate bone through these
Mesenchymal cell
becomes osteoprogenitor cells
osteoprogenitor cells
become osteoblasts
osteoblasts
produce osteoid
osteocyte
mature osteoblasts embedded in bone matrix
osteoclast
dissolve and absorb bone
Hydroxyapatite
Calcium phosphate
forms crystals
hardens matrix
provides strength
Vitamin D
For calcium absorption
Vitamin C
For collagen formation
Lamellae
Rings of calcified collagen
Perichondrium
Dense irregular CT
Covers and protects cartilage
Endochondral ossification
Bone forms as hyaline cartilage model. Osteoblasts fill model and secrete bone matrix (osteoid). Leaves spongy bone. Periosteal bud enters. Diaphysis elongate and medullary cavity forms. Epiphysis ossify. Hyaline cartilage remains as epiphyseal plates and articular cartilage
Intramembranous Ossification
Bone growth within a membrane
Skull bones, mandible, clavicles
Interstitial growth
Growth in length
Occurs at the epiphyseal plate
Appositional growth
Growth in thickness
Occurs at osteogenic layer of periosteum and endosteun
Calcium is required for
Muscle contraction
Neural function
Cardiac function
Blood clotting
vitamin D is needed for
calcium absorption
converts to calcitriol
Stress fracture
hairline fractures due to repeated impact
Pathologic fracture
fracture due to disease process
Simple fracture
bone breaks but does not break through skin
Compound fracture
broken ends of bone break through skin
Greenstick fracture
partial fracture; bone bends and frays
Colles fracture
wrist fracture; “dinner fork” deformity
Compression fracture
osteoporosis leads to fractures of vertebrae
Pott’s fracture
ankle fracture
Bone Repair
- Fracture hematoma: Blood clot forms
- Soft callus: Collagen deposited, Fibrocartilaginous CT forms
- Hard callus: Osteoblasts build trabeculae
- Remodeling: Osteoclasts remove excess, Compact bone develops