Ossification (bones) Flashcards
Cells that develop into osteoblasts. Found in the deep layers of the periosteum and the marrow.
Osteogenic (stem cell)
Cells: function is bone formation, location growing in portions of the bone, including periosteum and endosperm.
Osteoblasts (Forms bone formation)
Cells function is to maintain mineral concentration of matrix. Location found in the matrix(entrapped)
Osteocytes (maintain bone tissue)
Cells function is for bone resorption. Location found on bone surfaces and at sites of old, injured or unneeded bone. Degrade the matrix/bone, cause bone breakdown.
Osteoclasts
Protein collagen will bend but not stretch, provides flexible strength, proteoglycans.
organic matrix of the bone
Minerals hydroxapatite calcium phosphate salt provides bearing strength. Minerals fluoride, potassium, magnesium.
Inorganic matrix of the bone
Composed of blood vessels, nerves, central supply to the osteon with blood.
Haversian Canal
Perforating: moves blood between osteons
Volkmann’s Canals
The source of blood supply allowing smaller capillary beds to move from cell to cell. Small channels that connect connecting lacunae allowing nutrients and wastes to move.
Canaliculi
Concentric rings of calcified matrix.
Lamellae
Open pockets where osteocytes reside.
Lacunae
Tubular shaft that runs between the proximal and distal ends of the bone. Filled with yellow marrow, compact bone shell.
Diaphysis
The wider section at the ends of the bone. Spongy bone covers by compact bone. Enlarged to strengthen joint and attach ligaments.
Epiphysis
Acts like a shock absorber and reduces friction.
Articular cartilage
Outer fibrous layer of collagen
Periosteum
Plates of bone sandwiched between connective tissue membranes. No shaft or epiphyses. Bone marrow throughout spongy bone; no marrow cavity. Hyaline cartilage covers articular surfaces.
The structure of the Flat bone
Bone develops from a fibrous membrane, mainly in bones of skull.
Intramembranous ossification
Bone forms by replacing hyaline cartilage, long and short bone of skeleton.
Endochondral ossification
The increase in length of long bones.
Interstitial growth
The increase in length of bone thickness.
Appositional growth
Triggers chondrocyte proliferation in epiphyseal plates, resulting in the increasing length of long bones. Increases calcium retention, which enhances mineralization, and stimulates activity, which improves bone density.
Growth hormone
Promotes osteoblastic activity and the synthesis of bone matrix.
Thyroid hormone- Thyroxine
Needed to make calcium phosphate and calcium carbonate, which form the hydroxyapatite crystals that give bone its hardness.
Calcium
Needed for calcium absorption.
Vitamin D
Supports bone mineralization; may have synergistic effect with vitamin D.
Vitamin K
Structural component of bone
Magnesium and Fluoride
Reduces inflammation that may interfere with osteoblast function.
Omega-3 fatty acids
Stimulates osteoclast proliferation and resorption of bone by osteoclasts; promotes. Reabsorption of calcium by kidney tubules; indirectly increases calcium absorption by small intestines.
Parathyroid hormone (PTH)
Inhibits osteoclast activity and stimulates calcium uptake by bones.
Calcitonin
Caused by trauma, car accident, fall, athletics, etc.
Stress fracture
Bone is weekend by disease, bone cancer or osteoporosis
Pathological fracture
Break in the skin, multiple pieces.
Fractures classified by structural characteristics
Occurs straight across the long axis of the bone.
Transverse fracture
Occurs at an angle that is not 90 degrees.
Oblique Fracture
bone segments are pulled apart as a result of a twisting motion.
Spiral Fracture
Several breaks result in many small pieces between two large segments.
Comminuted fracture
One fragment is driven into the other, usually as a result of compression.
Impacted fracture
A partial fracture in which only one side of the bone is broken.
Greenstick
A fracture in which at least one end of the broken bone tears through the skin; carries a high risk for infection.
Open or compound fracture
A fracture in which the skin remains intact.
Closed or simple fracture.
Torn blood vessels lose blood at the damaged site. A mass of clotted blood forms at the fracture site about 6-8 hours after damage. Site becomes swollen, painful, and inflamed.
Step 1 in healing fractures, Hematoma.
Within about 48 hours of damage, chondrocytes from endosperm secrete fibrocartilaginous matrix to the internal callus. Osteoblasts and periosteal chondrocytes produce cartilaginous matrix that later calcifies to stabilize the damaged site external callus.
Step 2 in healing fractures, Soft Callus.
The fibers and cartilage of the internal and external calluses are ossified to produce bony callus composed of trabelculae. The spongy bone formation in the callus is usually 4-6 weeks after the injury.
Step 3 in healing fractures, Hard Callus
Excess material on the bone shaft exterior and in the medullary canal is removed. Compact bone is laid down to reconstruct shaft walls. The remodeling process may take more than a year to complete.
Step 4 in healing fractures, Remodeling.
Vitamin D deficiency
Rickets
Irregular thickening and softening of skull bones
Padget’s disease
Inflammation of backbone caused by TB
Pott’s Disease
Soft, weak bones that are demineralized
Osteomalacia
Bone resorption outpaces deposit. Spongy bone of spine and neck of femur most susceptible. Vertebral and hip fractures are common.
Osteoporosis
Indicates that the bone is stronger than normal
Positive T score
Indicates that the bone is weaker than normal.
Negative T score
Can confirm a diagnosis of osteoporosis if you have already had a bone fracture. Predict your chances of fracturing a bone in the future. Determine your rate of bone loss, see if treatment is working.
Bone Mineral Density (BMD) testing.
