Download Movement and Joints

Joint
• the movable or fixed place or part where two bones of a skeleton join. The Joints
• Fibrous
– Fibrous joints connect bones without allowing any movement. The bones of your skull and pelvis are held together by fibrous joints. The union of the spinous processes and vertebrae are fibrous joints. The Joints
• Cartilaginous
– Cartilaginous joints are joints in which the bones are attached by cartilage. These joints allow for only a little movment, such as in the spine or ribs.
The Joints
• Synovial
– Synovial joints allow for much more movement than cartilaginous joints. Cavities between bones in synovial joints are filled with synovial fluid. This fluid helps lubricate and protect the bones. Bursa sacks contain* the synovial fluid. III. Types of movement
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Flexion
Extension
Rotation
Abduction
Adduction
Circumduction
Flexion
• a bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the joint
Extension
• an unbending movement around a joint in a limb (as the knee or elbow) that increases the angle between the bones of the limb at the joint Rotation
• turning around as on an axis Abduction
• To draw away from the midline of the body or from an adjacent part or limb
Adduction
• moving of a body part toward the central axis of the body
Abduct – take away
Adduct – Add it to your body
Circumduction
• movement of a limb or extremity so that the distal end describes a circle while the proximal end remains fixed Movement Around Axes
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Nonaxial
Uniaxial
Biaxial
Multiaxial
Nonaxial
• Bone movement that is not around on an axis
plane joint
bones slide past
each other.
Midcarpal and
midtarsal joints
are gliding joints
Uniaxial
• the movements (flexion/extension) are all in one plane and around one axis, the joints are uniaxial Biaxial
• Since bones can move in both planes: side to side and back and forth movements the joints are biaxial Multiaxial
• The movements are allowed in all axes and planes: flexion/extension, adduction/abduction, circumduction and rotation. These joints are multiaxial. http://www.shockfamily.net/skeleton/BALLSOCK.MOV
Muscles, Bones, and Movement
Putting the “Operation” in cooperation
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. Plane (= gliding)
– Opposite bone surfaces are flat or slightly curved. – Only sliding motion in all directions are allowed. Since there is no bone movement around an axis, the joints are nonaxial. 2. Hinge
– Convex surface of one bone fits smoothly into concave surface of the second bone – The movements allowed are similar to those allowed by a mechanical door hinge. Since the movements (flexion/extension) are all in one plane and around one axis, the joints are uniaxial. 3. Pivot
– A rounded, pinted or conical surface of one bone is inserted into a ring made partly of another bone and partly of a ligament. – Since the only movement allowed is the rotation of one bone around its own axis, the Joints are uniaxial. 4. Ellipsoidal (= condyloid)
– Oval‐shaped surface fits into an oval‐shaped cavity (ellipse means oval). – The movements allowed are flexion/extension, adduction/abduction and circumduction but NO ROTATION. Since bones can move in both planes: side to side and back and forth movements the joints are biaxial. 5. Saddle
– First bone's articular surface is concave in one direction and convex in the other while the second bone is just the opposite (or if you prefer, one bone is shaped like a saddle, and the other is shaped like its rider). – The saddle joint is similar to the Ellipsoidal Joint but the movements are freer. The movements allowed are flexion/extension, adduction/abduction and circumduction but NO ROTATION. Since bones can move in both planes: side to side and back and forth movements the joints are biaxial. 6. Ball and socket
– Ball‐shaped head fits into a cup‐shaped depression – These joints are the most freely moving of all synovial joints. The movements are allowed in all axes and planes: flexion/extension, adduction/abduction, circumduction and rotation. These joints are multiaxial. Benefits of Synovial Fluid
• Reduces Friction
Benefits of Synovial Fluid
• reduces friction between the articular cartilage and other tissues in joints to lubricate and cushion them during movement. • This fluid forms a thin layer (approximately 50 micrometres) at the surface of cartilage, but also seeps into the articular cartilage filling any empty space. The fluid within articular cartilage effectively serves as a synovial fluid reserve. During normal movements, the synovial fluid held within the cartilage is squeezed out mechanically (so‐called weeping lubrication) to maintain a layer of fluid on the cartilage surface. Muscles, Bones, and Movement
Putting the “Operation” in cooperation
Seven Golden Rules of Muscle Activity
1. Muscles get smaller as they contract.
2. Muscles cross at least one joint.
3. The bulk of the muscle lies proximal to the joint crossed.
4. All muscles have an insertion and origin.
5. During contraction, the insertion moves toward the origin.
6. Muscles only pull; they never push.
7. Muscles work in pairs.
1.Muscles Get …..
Smaller
as they Contract.
Try it with your bicep!!!
2.Muscles Cross at Least One Joint
• Think drawbridge!!
• How can muscles effect movement if they don’t cross a joint?
• Where does the bulk of the muscle lie? Î
All Muscles Have an Insertion and an Origin
• Insertion = More moveable attachment
• Origin = Less moveable attachment
• Insertion is usually distal.
• Origin is usually proximal.
• Insertion moves toward origin during muscle contraction.
Muscles Only Pull
So how do they effect flexion AND extension? Abduction AND Adduction?
Because they work in PAIRS!!!!
Prime Mover = the muscle with major responsibility for effecting a movement.
Antagonist = the opposing muscle responsible for the opposite movement.
Muscles Work in Pairs
• A muscle can be both a prime mover and an antagonist. • Name some prime mover‐antagonist pairs.
Remember From Last Class…..
Joint
• the movable or fixed place or part where two bones of a skeleton join. The Joints
• Fibrous
– Fibrous joints connect bones without allowing any movement. The bones of your skull and pelvis are held together by fibrous joints. The union of the spinous processes and vertebrae are fibrous joints. The Joints
• Cartilaginous
– Cartilaginous joints are joints in which the bones are attached by cartilage. These joints allow for only a little movment, such as in the spine or ribs.
The Joints
• Synovial
– Synovial joints allow for much more movement than cartilaginous joints. Cavities between bones in synovial joints are filled with synovial fluid. This fluid helps lubricate and protect the bones. Bursa sacks contain* the synovial fluid. Joints
• Synovial membrane – Composed of soft areolar connective tissue.
• Bursa – flattened fibrous sacs found where bones, tendons, and ligaments come together. Function?
• Benefit of synovial fluid??
Benefits of Synovial Fluid
• Reduces Friction
• Protects the bone
Tendons and Ligaments
• Tendons – Attach muscle to bone
• Ligaments – Attach bone to bone.
• Form follows function???
Synovial Joints