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Skeletal System 4 Honors Anatomy to be copied Slide 2 Joints & Homeostasis Joints contribute to homeostasis by holding bones together in ways that allow movement & flexibility Slide 3 Joints aka: articulation or arthrosis a point of contact between 2 bones, a bone & cartilage, or between a bone & tooth Slide 4 Joint Classification 1. structural classification based on anatomical characteristics Fibrous joints Cartilagenous joints Synovial joints 2. functional classification based on type of movement they permit Synarthrosis Amphiarthrosis Diarthrosis Slide 5 Fibrous Joints Articulating bones held very closely together by fibrous CT 3 types: 1.Sutures skull bones 2.Syndesmoses interosseous membrane 3.Gomphoses dentoalveolar joint Slide 6 Gomphoses Slide 7 Cartilagenous Joints allows little or no movement bones are tightly connected by either hyaline cartilage or fibrocartilage 2 types: 1.Synchondoses hyaline cartilage connects bones epiphyseal plate 2.Symphyses fibrocartilage connects bone pubic symphysis Slide 8 Symphyses Slide 9 Synovial Joints distinguishing characteristics: synovial joint cavity filled with synovial fluid bones covered by articular cartilage reduces friction Slide 10 Synovial Fluid secreted by synovial membrane viscous, clear, pale yellow fluid forms film over surfaces w/in articular capsule functions: 1.reduce friction 2.absorbing shocks 3.supporting chondrocytes in w/in articular cartilage Slide 11 By the way. cracking sounds heard as joints move or popping sounds people make when the crack their knuckles explanation: When synovial cavity expands creates partial vacuum suction from that draws CO 2 & O 2 out of blood vessels in synovial membrane form bubbles in synovial fluid bubbles pop Slide 12 Sprains a forcible wrenching or twisting of a joint that stretches or tears ligaments but does not dislocate the bones occurs when ligaments are stressed beyond their capacity may have associated damage to surrounding blood vessels, muscles, tendons, or nerves Slide 13 Strains stretched or partially torn muscle often due to muscle contracting suddenly & powerfully Slide 14 Bursae saclike structures situated to alleviate friction in some joints filled with fluid similar to synovial fluid located between: skin & bones tendons & bones muscles & bones ligaments & bones Slide 15 Bursitis inflammation of a bursa usually caused by irritation from repeated, excessive exertion of a joint or by: trauma, infection (syphilis or TB), RA symptoms: pain, swelling, tenderness, limited movement Slide 16 Types of Movements @ Synovial Joints 1. Gliding relatively flat surfaces move back-and-forth & side-to-side Slide 17 Types of Movements @ Synovial Joints 2. flexion/extension/ hyperextension: opposite movements flexion: decrease in angle between articulating bones extension: increase in angle between articulating bones hyperextension: continuation of extension beyond the anatomical position Slide 18 Slide 19 Types of Movements @ Synovial Joints 3. abduction/adduction/ circumduction abduction: movement of bone away from midline adduction: movement of bone toward midline circumduction: movement of distal end of a body part in a circle Slide 20 Slide 21 Types of Movements @ Synovial Joints 4. elevation/depression: elevation: upward movement of part of body (closing mouth, shrugging shoulders) depression: downward movement of part of body (opening mouth, returning elevated shrugged shoulders to anatomical position) Slide 22 Slide 23 Types of Movements @ Synovial Joints 5. protraction/retraction protraction: movement of part of body anteriorly in transverse plane retraction: returning a protracted part of body to anatomical position Slide 24 Slide 25 Types of Movements @ Synovial Joints 6. inversion/ eversion inversion: movement of soles medially @ intertarsal joints (soles face each other) eversion: movement of soles laterally @ intertarsal joints Slide 26 Slide 27 Types of Movements @ Synovial Joints 7. dorsiflexion/ plantar flexion dorsiflexion: bending foot @ ankle in direction of dorsum (superior surface) plantar flexion: bending foot @ ankle in direction of plantar surface Slide 28 Slide 29 Types of Movements @ Synovial Joints 8. supination/pronation supination: movement of forearm in which palm is turned anteriorly pronation: movement of forearm in which distal end of radius crosses over distal end ulna & palm is turned posteriorly Slide 30 Slide 31 Types of Movements @ Synovial Joints 9. opposition movement of thumb in which thumb moves across palm to touch tips of the fingers on same hand Slide 32 Slide 33 Ball - & - Socket Joint ball-like surface of one bone fits into a cuplike depression of another bone permits movement around 3 axis + all directions in between flexion extension abduction adduction circumduction rotation Slide 34 Slide 35 Homeostatic Imbalances Rheumatoid Arthritis (RA) autoimmune disease: immune system attacks joint linings characterized by: inflammation of joint swelling, pain, loss of function usually bilateral joints involved but may not be to same degree Slide 36 Medical Terminology arthralgia: pain in a joint subluxation: partial or incomplete dislocation of a joint