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Joints. HOW MOVEMENT HAPPENS: Muscles Pull on Tendons to Move Bones at Connections called Joints or Articulations. Connections. Tendon. Ligaments. Ligaments connect bone-to-bone or reinforce joints
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HOW MOVEMENT HAPPENS: Muscles Pull on Tendons to Move Bones at Connections called Joints or Articulations Frolich, Human Anatomy, Mechanics of Movement
Connections Tendon Ligaments • Ligaments connect bone-to-bone or reinforce joints • Some ligaments limit the mobility of articulations, or prevent certain movements altogether • Generally regular connective tissue • Musculo-skeletal connections • Muscle to bone • Muscle to muscle • Bone to bone • Can have various shapes Frolich, Human Anatomy, Mechanics of Movement
Ligaments Frolich, Human Anatomy, Mechanics of Movement
Joints or Articulations • Connections between bones • Usually, but not always allow for movement • Formed from various connective tissues • Fibrous • Cartilaginous • Synovial (most complex--typical limb joints) Frolich, Human Anatomy, Mechanics of Movement
Fibrous joints • Suture • Bones tightly bound by minimal fiber • Only found in skull Fig. 9.1 a, M&M
Fibrous joints • Syndemoses • Bones connected by ligaments • E.g. tibiofibularligament Fig. 8.4, M&M
Fibrous joints • Gomphoses • Peg in socket joint • Only found in teeth/alveoli
Cartilaginous Joints Symphyses Synchondrosis • Fibrocartilage unites bones • Pubic symphysis • Intervertebral disc • Hyaline cartilage unites bones • Epiphyseal growth plates • Costal cartilage-sternum
Synovial Joints • Most common joints in body • Most mobile joints • Have • Articular surfaces on bone with hyaline cartilage • Completely enclosed joint capsule formed from ligaments • Synovial fluid within capsule lubricates joint • Some have meniscus or articular disc(e.g. knee, jaw joint) Frolich, Human Anatomy, Mechanics of Movement
Also see Fig. 9.3, M&M Frolich, Human Anatomy, Mechanics of Movement
Synovial Joint Shape Types • Plane joints--intercarpal joints • Hinge joints--elbow,ankle, interj-phalangeal • Pivot joints--radio-ulnar joint The type of joint, in part, determines the range and direction of movement Frolich, Human Anatomy, Mechanics of Movement
Synovial Joint Shape Types • Condyloid joints (egg into oval)--metacarpo-phalangeal • Saddle joints--carpo-metacarpal joint of thumb • Ball-and-socket--hip, shoulder Frolich, Human Anatomy, Mechanics of Movement
X-ray of hand affected by arthritis Frolich, Human Anatomy, Mechanics of Movement
Artificial Hip Joint Frolich, Human Anatomy, Mechanics of Movement