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Joints are classified by:
- Function: amount of movement
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- Structure: material that binds the bones together
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Funtional Classification:
1)
2)
3)
- 1) Synarthroses
- 2) Amphiarthroses
- 3) Diarthroses
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Define Synarthroses:
Functional Classification of Joints. Synarthroses are immovable joints.
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Define Amphiarthroses
Functional Classification of joints. Amphiarthroses are slightly moveable joints.
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Define Diarthroses
- Functional Classification of Joints.
- Diarthroses are freely moveable joints. Predominant in the limbs.
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Name Structural Classifications of joints:
1)
2)
3)
- 1) Fibrous
- 2) Cartilaginous
- 3) Synovial
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Define Fibrous classification of joints:
Bones are connected by fibrous tissue, mainly DRCT. No joint cavity present. Most are immoveable. Sutures, syndemoses (interosseous membrane between radius and ulna), gomphoses (tooth).
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Define Structural Classification for Cartiliginous Joints
Articulating bones are united by cartilage. Lack a joint cavity, not highly moveable. Two types: Synchondroses (hyaline cartilage unites bones) and symphyses (epiphyseal plates).
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Define structural classification of Synovial Joints
- "Joint Eggs"
- Most moveable joints of the body. Contains a fluid filled joint cavity.
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Name 6 basic features of synovial joints:
- 1) Articular cartilage
- 2) Joint cavity
- 3) Articular Capsule
- 4) Synovial Fluid
- 5) Reinforcing Ligaments
- 6) Nerves and Vessels
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Name the three factors that stabilize synovial joints:
- 1) Shapes of articular surfaces
- 2) Number and position of stabilizing ligaments
- 3) Muscle tone
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Compare and contrast Bursae and Tendon Sheaths
- Bursa is a flattened fibrous sac lined with synovial membrane. Occures where ligaments, muscles, skin, tendons or bones overlie each other.
- Tendon Sheath is an elongated bursa that wraps around a tendon like a bun around a hot dog.
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Name three movements allowed by synovial joints:
- 1) Gliding, such as in carpals and tasals and between the flat articular processes of the vertebrae.
- 2) Angular Movements, increase or decrease the angle of two bones. Includes flexion, extension, absuction, adduction and cicumduction.
- 3) Rotation, turning mocement of a bone, such as between the first two cervical vertebrae.
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Define Supination and Pronation
- Supination and Pronation refer to movements of the radius and ulna.
- Supination occurs when forearm ratates laterally so that the palm faces up. "Sup, give me five" (haha)
- Pronation occurs when forearm rotates medially so palm faces down.
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Describe Plane Joints
Synovial joint where the articular surfaces are flat planes.
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Describe Hinge Joints
- Synovial Joint
- Cylindrical end of one bone fits into trough shaped surface on other bone.
- Elbow and Ankle
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Describe Pivot Joints
- Synovial Joint
- Rounded end of one bone fits into a ring that is formed by another bone plus an encircling ligament.
- Example: joint between atlas and the dens of the axis.
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Describe Condyloid Joints
- Synovial joint
- Egg shaped articular surface fits into oval concavity. Allows bone to travel 1) side to side 2) back and forth.
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Describe Saddle Joint
Synovial Joint with both convex and Concave areas like a saddle.
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Describe Ball and Socket Joints
- Synovial Joint
- Spherical head of one bone fits into a round socket of another.
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Name 4 functions of Muscles
- 1) Movement
- 2) Maintenance of posture
- 3) Joint Stabilization
- 4) Heat Generation
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Name the three Types of Muscle Tissue
- 1) Skeletal Muscle
- 2) Cardiac Muscle
- 3) Smooth Muscle
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Name 3 sheaths of Skeletal Muscle bundles / fibers
Connective Tissue and Fascicles
- 1) Epimysium - Overcoat of DICT
- 2) Perimysium - Surrounds each fascicle (muscle fibers grouped into bundles of 'sticks')
- 3) Endomysium - Within a fascicle, each muscle fiber is surrounded bu a fine sheath of CT reticular.
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Define Myofibril
Striations of long rod shaped organelles called Myofibrils within the sarcoplasm. Myofibrils are unbranched cylinders.
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Define Sarcomere
- Sarcomeres are repeating segments in a myofibril.
- The Sarcomere is the basic unit of contraction in teh skeletal muscle.
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Identify 2
Thick (myosin) filament
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Identify 3
Elastic (titin) filaments
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Describe Sliding Filament Theory
- Describes the mechanism of skeletal muscle contraction.
- Myosin heads of the thick filaments attach to thin filaments at both ends of the sarcomere and pull the thin filaments towards the center of teh sarcomere. Myosin will "hinge", then it will "recock" and bing to the thin filament farther along its length.
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Define Titin
Spring like molecure in sarcomeres that resists overstretching.
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Define T Tubules
Deep invaginations on the sarcolemma that run between the cisternae of the sarcoplasmic reticulum.
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