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Osteology First Test
Question | Answer |
---|---|
The name for the red blood cell-producing capacity of some bones | Haematopoiesis |
Vascular Supply Enters at the diaphysis here | Nutrient Foramen |
Pronation and Supination AND Medial Lateral Rotation occur on which plane and axis | Transverse Plan and the superior and Inferior axis |
Flexion and Extension occur on which plane and axis | Sagittal Plane and the mediolalteral axis |
Abduction and Adduction occur on which plane and axis | Coronal place and the anterior posterior axis |
What are the three communication systems of bone | Haversian Canals, Canaliculi, Volkmann's Canals |
Where does Haematopoiesis occur | The medullary cavity |
What components are bone made up of | Organic and Inorganic |
What constitutes the organic components of bone | Collagen |
What constitutes the inorganic components of bone | Hydroxyapatite- which precipitates through the collagen fibers to give bone its hardness |
What are the types of bone cells | Osteoblasts, Osteocytes, Osteoclasts |
What does an Osteoblast do | Derived from osteoprogenitor cells. Bone forming cells. Produce Osteoid. |
What does an Osteocyte do | "Matured bone cells". Become trapped within the matrix, and reside in lacunae. They no longer produce osteoid, and develop canliculi. |
Three phases of an osteocyte | Formative- osteoid is laid down trapping cells to become osteocytes, which are now found in lacunae and produce canaliculi. Resorptive- release calcium and other minerals via signals received from hormones. Degenerative- self explanatory |
What does an Osteoclast do | larger cells that are used in the resorption of bone |
Where do Osteoclasts come from | derived from monocytes in blood. NOT MESENCHYMAL! |
Where are Osteoclasts found | Howship's lacunae |
What are the two types of bone | Immature or Woven Bone and Mature or Lamellar Bone |
What is Woven Bone | First kind of bone present in the womb or injury. Very rapid formation. Higher amount of osteocytes compared to mature bone. Not organized. |
What is Mature Bone | Ordered. Formed by repeated addition of lamellae or layers. Very dense. Composted of Haversian systems or osteons. |
Three layer of Lamellar Bone | Endosteum, periosteum, and compact bone. |
What is Compact bone | Outer region with many layers. Middle region composed of Haversian systems, and is oriented with the long axis of the bone. Inner region has circumferential lamella. |
What is a cement line | The outer line that delineates an active Haversian system. |
What is interstitial lamellae | remains of osteon where remodeling has occurred. |
When does bone first appear | 7 weeks post-conception |
How does bone form | Intramembraneous and endochondral |
What do intramembraneous and endochondral ossification have in common | Both develop from existing tissues. Osteogenesis is induced by the invasion of blood cells. |
What is the intramembraneous ossification process (simplified) | Mesoderm -> Mesenchyme -> Bone |
What is the endochondral ossification process (simplified) | Mesoderm -> Mesenchyme -> Cartilage -> Bone |
Intramembraneous ossification process (7 steps) | Mesenchymal cells migrate, Condensation and proliferation of mesenchymal cells to membrane, Membrane will contain OPCs. Membrane becomes vascularized, OPCs become osteoblasts and secrete osteoid, blood vessels bring the osteoclasts (monocytes), Condense |
Primary sponglosa | Spicules of bone |
What happens to the original mesenchyme cells that were condensed in step two of intramembraneous ossification | They become the Periosteum and Endosteum |
Spongy bone is also called | Diploe |
What are the layers of a flat bone | Outer compact bone, spongey bone, trabeculae, inner compact bone |
Endochondral ossification process (beginning to the hypertophy of some chondrocytes) | Mesenchymal cells condense and proliferate, Become chondroblasts and secrete collagen, some become chondrocytes, build up hyaline cartilage(nobv), surrounded by a mesenchyme membrane that has OPC, Hyaline grows and chondrocytes in center hypertrophy. |
Endochondral ossification process (Vascularization to end) | Perichondrium vascularized, OPCs become osteoblasts and secrete osteoid and create a periosteal collar around diaphyis and calcifies into bone, Capillaries create nutrient foramen, these create medullary, hyaline is vascularized 2centers of oss. |
What does anlage mean | the rudimentary basis fo a particular organ to other part. Cartilage to bone. |
Where does cartilage remain after endochondral ossification | Epiphyseal growth plate and articular surfaces of ephipyses |
Appositional Growth | Increase in diameter by adding bone under the periosteum |
Longitudinal Growth | Increases bone length by adding new bone at the growth plates |
4 cell layers of Endochondral ossification end to shaft | 1. Reserve cell layer- Differentiation to chondroblasts, 2. Proliferative/Matrational zone- chondrocytes divide frequently, 3. Hypertrophic zone-chondrocytes mature, calcium deposition (area of degenerative cells), 4. Zone of ossification-growth |
What are joints | Where two or more bones come together |
Joint Classifications | Functional and Structural |
What are the types of functional joints | Immovable, slightly moveable, fully movable |
What are the types of structural joints | fibrous, cartilaginous, synovial |
What are Synarthroses | Fibrous immoveable joints. Bones that are in close contact that are separated by a thin layer of fibrous connective tissues. |
Types of Synarthroses | Sutures, Syndesmoses (fibula and tibia at the distal ends), Gomphoses (between teeth) |
What are Amphiarthroses | Slightly moveable cartilaginous joints, Bones are connected by hyaline cartilage or fibrocartilage |
Types of Amphiarthroses | Synchondroses(epiphyseal plates), Symphyses |
What are Diarthroses | Freely movable, synovial joints. Made of four parts. 1.Fibrous joint capsule, 2.Synovial membrane, 3. Joint cavity containing synovial fluid, 4. Hyaline cart |
What is a bursa | Fluid filled sac interposed between joint capsules and overriding tendons. |
Types of Diarthroses | Hinge joints (elbow), Pivot joint (radius ulna), Condyloid joint (mc-mc), Saddle joint( thumb), plane joint (fingers), Ball and socket(shoulder) |
First order Lever | Load and Power on opposite sides of the fulcrum. (Shaking head no) |
Second order levers | Load is imposed between the fulcrum and the power. (tippy toes) |
Third order levers | Power lies between the fulcrum and the load. (Bicep curls) |
The force needed to produce movement is a function of | Distance between the power of the fulcrum and the distance between the load and the fulcrum |
The longer the distance between the power and the fulcrum | the less work/effort/force needed |
Limits of joint function and flexibility | Shapes of bone surfaces (reciprocal-fit together, wider contact area-more stable), Intervening muscle or fat, laxity of ligaments, extensiblity of collagenous tissue of muscle, temperature |
Bone is a responsive tissue | it grows and responds to stress |
Bone modeling | The process of which bone mass increases to alter size, shape and structure |
Bone remodeling | the process of which bone mass adapts, altering size, shape, structure to the mechanical demands placed upon it |
What are the three steps of bone remodeling | 1. Activation of osteoclasts, 2. resorption by osteoclasts, 3. new bone deposits by osteoblasts. |
What are the influences of bone modeling and remodeling | Genetic, and Epigenetic (non-genetic) |
What is Wolff's law | Every change in the form and function of a bone or of their function alone is followed by certain definitive changes in their internal architecture and equally definite secondary alterations in their external condition, in accord with mathematical laws |
What are the loads bones experience | Tension, compression, bending, shearing, torsion, combo |
Tension results in | Resorption of the bone |
Compression results in | Deposition of bone |
Young's modulus of elasticity | (Force/area)/ (strain"(elongated length-original length"/original length) |