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Types of Joints and the Anatomy of the Synovial Joint. What is an Articulation (Joint). Point of contact between two bones **There are three types of joints. 1. Fibrous Joints. Also called “sutures”
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What is an Articulation (Joint) • Point of contact between two bones **There are three types of joints
1. Fibrous Joints • Also called “sutures” • These joints are bound tightly together by connective tissue and allows ZERO movement (immovable joint) • Ex. Interlocking bones of the skull
2. Cartilaginous Joints • Occur where the body of one bone connects to the body of another bone by means of cartilage and allows SLIGHT movement • Ex. Intervertebral discs
3. Synovial Joints • Occurs where bony surfaces are separated by a lubricating fluid (synovia) and by cartilage • Also joined by ligaments, which enclose the ends of articulating bones and form the synovial-containing capsule • Allows MOST movement
Examples of Synovial Joints Knee Ankle Elbow Shoulder
1. Articulating Cartilage • Allow for smooth contact surface • Acts as a shock absorber
2. Joint Cavity • Located between two bony articulating surfaces • Filled with synovial fluid (joint lubricant) • Essential in reducing friction and providing nutrients for articulating cartilage
3. Joint Capsule • Fibrous structure that consist of the: • Synovial membrane (allows certain nutrients to pass through to synovial fluid) • Fibrous capsule (keeps synovial fluid from leaking) ** Membrane is medial to capsule
4. Bursae • Small flattened sacs • Prevents friction between tendons, ligaments and bones
Intrinsic Ligaments • Thick bands of fibrous connective tissue • Helps thicken and reinforce the joint capsule • Ex. Forming the joint capsule or the meniscus of the knee
Extrinsic Ligaments • Separate from the joint capsule and help to reinforce the joint by attaching bones together
Gliding Joint • Also known as a “plane” or “arthrodial” joint • Connects flat or slightly curved bone surfaces • Ex. Joints between tarsals • Ex. Joints between carpals
Hinge Joints • Also known as a “ginglymus” joint • Think of the hinge of a door… • Convex portion of one bone fitting into a concave portion of another • Allows movement on one plane • Ex. Joint between phalanges • Ex. Joint between humerus and ulna • Ex. Joint between femur and tibia
Pivot Joints • Also known as a “trochoid” joint • Allows rotation in one plane (uni-axial) • A rounded point of one bone fits into a groove of another • Ex. Atlantoaxial joint (between atlas and axis– shake head “no”) • Ex. Between radius and ulna at humerus
Ellipsoid Joints • Allows movement on two planes (bi-axial) • Ex. Metaphalangeal joint
Saddle Joints • Allows movement in two planes • Movements include flexion/extension and abduction/adduction • Does not have a ball-and-socket rotation • Ex. Carpo-metacarpal articulation
Ball and Socket Joint • Also known as a “spherodial” joint • “Ball” at one bone fits into the “socket” of another, allowing movements around all three axis • Ex. Hip • Ex. Shoulder