Term
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Definition
-regions of the skeleton where bones articulate, sometimes allowing moveent between bones, and sometimes facilitating growth of the bones they interconnect
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Term
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Definition
1. Synarthrosis a. synostosis b. synchondrosis c. syndesmosis 2. Amphiarthrosis 3. Diarthrosis |
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Term
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Definition
-characterized by little/no movement between opposoing bones 3 types a. synostosis b. synchondrosis c. syndesmosis |
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Term
| Synarthrosis Joint - Synostosis |
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Definition
-bones joined by bones (no movement) -stabilize parts of skeleton after bone growht stops ex. cranial bones |
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Term
| Synarthrosis Joint - Synchondrosis |
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Definition
-bones connected by hyaline cartilage (little movem) -permit continued bine growth and expansion via endochondral ossification ex. epiphyseal plates union of first rib to sternum (adults) |
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Term
| Synarthrosis Joint - Syndesmosis |
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Definition
-bones that are far apart are united by ligament composed of dense connective tissue (limited movement) -shock absorbers -sites of appositional bone growth ex. union between distal tibia and fibula |
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Term
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Definition
-found where fibrocartilage is the interosseous medium -capable of slight movement ex. intervertebral joints pubic symphysis
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Term
Diarthrosis (synovial joint) |
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Definition
-found between long bones -wide range of movement |
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Term
Organization of Diarthroidal Joint 5 components |
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Definition
1. Articular Capsule 2. Articular Activity 3. Articular Cartilage 4. Intra-articular Menisci (discs) 5. Classification |
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Term
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Definition
Bones of diarthroidal join lined by ligaments and outer capsule Outer Capsul composed of: 1. fiberous layer 2. synovial membrane (synovium) |
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Term
| Articular Capsule - Fiberous Layer |
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Definition
-outer layer -dense fiberous connective tissue -continuous with periosteum containing blood vessels and nerves |
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Term
Articular Capsule - Synovial Membrane (synovium) |
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Definition
-inner layer -lined by 1-3 layers of synovial cells (synovocytes) -produces and resorbes synovial fliud -removes material shed into articular cavity -richly vascularized and innervated -arranged in folds and villi -faces articular cavity -does NOT line articular cartilage |
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Term
Articular Capsule - Synovial Membrane (synovium) 2 Cell Typed |
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Definition
Type A (machrophage-like) cells: -light staining phagocytic cells Type B (fibroblast-like) cells: -dark staining -secret hyaluronic acid -secrete glycoprotein lubricant in synovial fluid
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Term
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Definition
-space enclosed by the capsule -contians colorless, viscous synovial fluid -lubricates articular surfaces -provides nutrients + oxygen for articular cavity -synovial fluid is noted for a high amount of hyaluronic acid and glycoproteins and a small population of leukocytes (mainly monocytes)
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Term
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Definition
-surfaces bones of joint -type of hyaline cartilage -absence of perichondrium -collagen fibers form wide arches -arranged perpendicularly to surface of bone -parallel to articular surface near that surface |
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Term
| Articular Cartilage - Chondrocytes |
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Definition
-stacked in columns near osseous surface -solitary and flat near articular surface |
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Term
| Articular Cartilage - Structure |
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Definition
-resilient and efficient absorber of intermittent mechanical pressure -consists of cells and matrix (type II collagen, proteoglycans, up to 80% H2O) Proteoglycans: -rich -highly branched hydrophilic glycosaminoglycans -contain lots of H2O = function as biochemical spring |
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Term
| Articular Cartilage - Biochemical Spring |
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Definition
Pressure = water forced out of matrix to synovial fluid Reciprocal electrostatic repulsion of negatively charged carboxyl and sulfate groups in GAG molecules =seperate GAG branches = creates space to be filled with H2O Pressure released = H2O attracted back into the spaces |
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Term
| Articular Cartilage - water movement |
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Definition
-due to use of the joint -responsible for resiliency of cartilage -essential for nutrition -facilitate interchage of O2, CO2, and other molecules b/w synovial fluid and articular cartilage
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Term
Articular Cartilage 3 Zones |
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Definition
1. Superficial Zone -chondrocytes small, flat -collagen fibers parallel to surface 2. Middle (transitional) Zone -chondrocytes in columns (deeper chondrocytes enlarged) -collagen fibers go from horizontal to veritcal 3. Deep Zone -calcified cartilage -small chondrocytes -adjacent to subchondral bone -collagen perpendicular to surface |
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Term
Intra-Articular Menisci (discs) |
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Definition
-cushions of fibrocartilage or dense fiberous connective tissue -free or transverse the joint |
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Term
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Definition
1. simple = 2 articulating surfaces ex. knee joint 2. compound = 3+ articulating surfaces ex. TMJ
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Term
Temporomandibular Joint (TMJ) |
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Definition
-type of gliding-hinge synovial joint -found only in mammals -articulation of mandibular condyle with temporal bone by way of glenoid fossa |
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Term
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Definition
1. Mandibular Condyles 2. Articular Surface of the Temporal Bone 3. Capsule 4. Articular Disk 5. Ligaments 6. Muscle |
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Term
Mandibular Condyle (5 layers) |
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Definition
-ovoid structure -long axes oriented posteromedially Composed of (several layers): 1. dense fiberous connective tissue
2. proliferative zone -layer of cells acting as replicating pool for underlying cartilage
3. fibrocartilage (hyaline during growth period)
4. calcified cartilage
5. sub-articular bone
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Term
Articular Surface of Temporal Bone (2 components) |
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Definition
1. Articular Eminence - composed of several layers superficial --> deepest a. dense fiberous con. tis. (fiberous layer) b. proliferating zone c. fibrocartilage d. bone 2. Glenoid Fossa -concave depression -squamous part of temporal bone -covered by thin fiberous layer (periosteum)
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Term
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Definition
-fiberous membrane that surrounds the joint -incorporates articular eminence -dense fiberous connective tissue upper half = loose envelope -posterior attachment at squamotympanic fissure -anterior attachment at articular eminence -lateral attachment at glenoid fossa -attached to articular disk: medially, laterally, poste. -capsule firmly attached to neck of mandibular condyle
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Term
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Definition
-functions as articular surface -divides TMJ into 2 distinct compartments -anterior and posterior -fiberous connective tissue -avascular + aneural centrally -vascular + innervated at periphery -biconcave -attached to medial and lateral poles of condyle -attachment to capsule in previous card |
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Term
Anterior Portion of Articular Disk (2 lamellae) |
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Definition
-appears to split into 2 lamellae Upper Lamellae= -runs foward -fuses with capsule and periosteum of anterior slope of articular eminence Lower Lamellae= -attached to anterior surface of condylar neck Superior head of lateral pterygoid inserts b/w lamellae |
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Term
Posterior Portion of Articular Disk (2 lamellae) |
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Definition
-also appears to split into upper + lower lamellae Upper Lamellae= -fiberous + elastic connective tissue -inserts into squamotympanic fissure (as part of capsule) Lower Lamellae= -merges with periosteum of condylar neck Between posterior lamellae = zone containing retrodiscal tissue = loose vascular connective tissue
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Term
Ligaments Temporomandibular Ligament |
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Definition
-lateral portion of capsule -thickened and fan-shaped -runs in an oblique course -posteriorly and inferiorly form lateral aspect of articular eminence to posterior part of condylar neck
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Definition
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