Skeletal System Flashcards
Function of Skeletal System
structural support, protection of vital organs, mechanism for movement, storage of vital minerals, source of blood cells.
Bone Shapes
Flat, irregular, short, long, sesamoid
Trabecular Bone
(aka cancellous bone, spongy bone)
network of bone tissue and marrow, strength for tensile and compressive biomechanical forces
Cortical Bone
more dense network of bone tissue that typically forms the hard outer surface
Osteoblasts
bone deposition
Osteocytes
calcified osteoblasts, bone material
Osteoclasts
bone resorption
Matrix Composition
collagenous, non collagenous proteins, inorganic mineral salts, osteoblasts, osteoclasts, osteocytes
Fractures, types
Closed, open, transverse, spiral, comminuted, impacted, greenstick, oblique
Inflammatory phase
immediate onset, 3-5 days. bleeding in local area results in hematoma. hematoma provides the structural stability for new bone formation.
Proliferative, (reparative) phase
early onset (first few days of injury), peaks 7-10, lasts 2-6 weeks. hematoma are replaced by fibrous tissue and osteoblasts begin laying down a soft internal callus. Not yet ready for loading.
Remodeling (maturation) phase
begins around the 3rd week, peaking around 6-8 weeks, lasts 6-24 months. Osteoclasts resorb some external callous. Can sustain biomechanical load.
Healing risk factors
Movement during bone healing phase
Poor circulation, smoking, metabolic disorders
Medications: corticosteroids, immunosuppressants
Advanced age
Poor nutrition, lacking calcium and vit D
OT Implications: Imflammatory and Proliferative Phase
splint, immobilize
interventions focused on modify/adapt toward occupations and activities
“revise the current context or activity demands to support OT performance in natural setting”
OT Implications: Remodeling Phase
Restore a skill or ability that has been impaired
Stretching, strengthening program restore neuromuscular functions
Wolf’s Law
a bone will adapt (remodel) according to the bio-mechanical load placed on it.
Osteoporosis
Trabecular bone is resorbed faster than it is remodeled, resulting in decrease in bone density
Osteoporosis: Risk Factors
Reduction of estrogen in post-menopausal woman
Family history (genetics)
Personal history of falls
Long-term enforced bedrest
Low activity levels
Malnutrition (lack of CA and D)
High alcohol intake
Smoking
Joints
Where two or more bones articulate to produce movement
Fibrous joints
fibrous connective tissue
no movement between articular surfaces
e.g. coronal suture, interosseous membranes
Cartilaginous Joints
variable amounts of fibrous connective tissue
little movement
e.g. costosternal joint, symphysis pubis
Synovial Joints
- fibrous articular capsule
- synovial membrane
- joint cavity/ space
- synovial fluid
- articular cartilage
Uniaxial joints
one degree of freedom (1 df)
- hinge joints (flx/ext)
- pivot joints (rotation)
e. g. interphalangeal joints
Biaxial joints
two degrees of freedom (2 df)
- saddle joints (flx/ext, abd/add) each articular surface is both convex and concave
e. g. sternoclavicular - condyloid joints (flx/ext, abd/add) convex surface, concave surface
e. g. metacarpophalangeal, atlantooccipital, scapulothoracic
Multiaxial joints
three degrees of freedom (3 df)
- ball and socket joints (infinite number of complex movements) most mobile, least stable
e. g. glenohumeral joint, pelvifemorad joint - plane joints (infinite number)
e. g. intercarpal joints
