Chapter 8 Articulations and Movement Articulations or Joints • Articulation or Joint – Place where two bones come together – Freely moveable to limited to no apparent movement – Structure correlated with movement Classes of Joints • Structural: Based on major connective tissue type that binds bones – Fibrous – Cartilaginous – Synovial • Functional: Based on degree of motion – Synarthrosis: Nonmoveable – Amphiarthrosis: Slightly moveable – Diarthrosis: Freely moveable Fibrous Joints • Characteristics – United by fibrous connective tissue – Have no joint cavity – Move little or none • Types – Sutures – Syndesmoses – Gomphoses Syndesmoses • Bones farther apart than suture and joined by ligaments (holds bone to bone) • Some movement may occur Gomphoses • Specialized joints • Pegs that fit into sockets • Inflammations – Gingivitis – Periodontal disease Cartilaginous Joints • Unite two bones by means of cartilage • Types – Synchondroses • Joined by hyaline • Little or no movement – Symphyses • Fibrocartilage uniting two bones Concept Check 1. What is articulation? -point of contact b/n two bones 2. What type of joint is gomphoses? symphyses? -Fibrous Joint in jaw (holds teeth); Fibrous Joint 3. What is the difference b/n synarthrosis, amphiarthrosis, & diarthorsis? -non-moveable; slightly moveable, and freely moveable Synovial Joints • Allow considerable movement • Most joints that unite bone of appendicular skeleton • Complex – – – – Articular cartilage and disks Joint cavity and capsule Synovial membrane and fluid Ligments and menisci • Bursae – Pockets of synovial fluid *reduces friction* – Bursitis Types of Synovial Joints • • • • • • Plane or gliding Saddle Hinge Pivot Ball-and-socket Ellipsoid *See Table 8.2 pg. 247 Types of Synovial Joints • Uniaxial-movement @ 1 axis & 1 plane • Biaxial- 2 perpendicular axis & 2 perpendicular planes • Multiaxial- 3 or more axes & 3 or more planes Plane and Pivot Joints • Plane or Gliding Joints – Monoaxial/Slight Movement – Example: • Articular processes between vertebrae (intervertebral) • Sacroiliac • Pivot Joints – Monoaxial/Rotation – Example: • Articulation between dens of axis and atlas • Radius w/ ulna Saddle and Hinge Joints • Saddle Joints – Biaxial/Slight Movement – Example: Thumb • Hinge Joints – – – – Monoaxial Example: Elbow, Knee Multiaxial Example: • Ankle-One predominates Ellipsoid and Ball-and-Socket Joints • Ellipsoid – Modified ball-andsocket – Biaxial – Example: Atlantooccipital Joint • Ball-and-Socket – Multiaxial – Examples: Shoulder and Hip joints Types of Movement • Gliding • Angular – Flexion and Extension • Hyperextension • Plantar and Dorsiflexion • Circular – Rotation – Pronation and Supination – Circumduction Flexion and Extension Anterior/Ventral Posterior/Dorsal Dorsiflexion and Plantar Flexion heel toes Abduction and Adduction “take away” “bring together” Rotation and Pronation and Supination “face down” “lying face up” Circumduction Combination of flexion, extension, abduction, & adduction Special Movements • Unique to only one or two joints – Types • Elevation and Depression • Protraction and Retraction • Inversion and Eversion Elevation and Depression superior inferior Protraction and Retraction anterior posterior Inversion and Eversion medial lateral Concept Check • How are joints classified? – Structural; Degree of movement • What type of joint makes up most of the appendicular skeleton? – Synovial Joints • What components make up a synovial joint? – Synovial membrane, joint cavity, joint capsule, articular cartilage, ligaments, tendons, menisci, bursae Knee Joint • Modified hinge joint • Menisci: Fibrocartilage articular disks – Pad of cartilage b/n bone of a synovial joint – Cup-shaped for stability; cushion; guide; shock absorber • Cruciate ligaments: ACL and PCL • Collateral ligaments: Fibular and tibial Parts of the Knee • Bones: Femur, Patella, Tibia, Fibula • Muscles: Quadriceps, Hamstrings • Actions: Flexion, Extension • Ligaments: – – – – Anterior Cruciate: prevents forward movement of tibia (ACL) Posterior Cruciate: prevents forward movement of femur (PCL) Lateral Collateral- (Fibula) LCL Medial Collateral- (Tibia) MCL • Tendons: Patellar Tendon (Tibia) • Cartilage (Fibrous Articular Cartilage): – Medial Meniscus- shock absorber – Lateral Meniscus- shock absorber Knee Injuries and Disorders • Football injuries • Bursitis • Chondromalacia – Softening of cartilage • Hemarthrosis – Blood accumulation w/n joint cavity – Acute; swollen knee • “Water on the knee” – Slower accumulation of fluid may be caused by bursitis Other Knee Disorders • Osgood Schlatter- patellar tendon pulls away from tibia causing fracture & new bone growth – Associated w/ younger athletes • Unhappy Triad - MCL, ACL, & Medial Meniscus – Caused by posterior, lateral blow or hit • Dislocated Patella- medial forced w/ slightly flexed knee – Patella flips over • Bucket Handle Tear- meniscus tears & piece fills in cavity Knee Repair • Arthroscopy- using tools & camera to see inside of joint – Ligament of cartilage repair, doesn’t need full open exposure to repair • Arthroplasty- knee replacement – Diseased or damaged joint Sprains/Strains • Sprain- ligaments • Strain- muscle tendons • 1st Degree- stretch • 2nd Degree- stretch & partial tear • 3rd Degree- complete tear Joint Disorders • Arthritis – Osteoarthritis: Wear and tear – Rheumatoid: Caused by transient infection or autoimmune disease • Joint infections – Lyme disease: Bacterial infection; Tick vector • Gout – Metabolic disorders of unknown cause (idiopathic; arising spontaneously - cause unknown) Effects of Aging on Joints • Tissue repair slows • Production of synovial fluid declines • Ligaments and tendons become less flexible • Decrease in ROM (Range of Motion) Concept Check • – • – • – What is the function of menisci? Cup shaped to help with stability, cushion, & guide the knee What is the difference b/n a ligament & a tendon? Ligaments connect bone to bone; Tendons connect muscle to bone What is the difference b/n arthroplasty arthroscopy? Arthroscopy: using tools/camera to see inside the joint; Arthoplasty: knee replacement