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Joints. Articulations of bones Functions of joints All joints hold bones together Allow for mobility Ways joints are classified Functionally Structurally. Functional Classification of Joints. Synarthroses Immovable joints Amphiarthroses Slightly moveable joints Diarthroses
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Joints • Articulations of bones • Functions of joints • All joints hold bones together • Allow for mobility • Ways joints are classified • Functionally • Structurally
Functional Classification of Joints • Synarthroses • Immovable joints • Amphiarthroses • Slightly moveable joints • Diarthroses • Freely moveable joints
Structural Classification of Joints • Fibrous joints • Generally immovable • Cartilaginous joints • Immovable or slightly moveable • Synovial joints • Freely moveable
Summary of Joint Classes [Insert Table 5.3 here] Table 5.3
Fibrous Joints • Bones united by fibrous tissue • Example: • Sutures • Syndesmoses • Allows more movement than sutures • Example: Distal end of tibia and fibula
Cartilaginous Joints • Bones connected by cartilage • Example: • Pubic symphysisIntervertebraljoints
Synovial Joints • Articulating bones are separated by a fibrous articular joint cavity • Synovial fluid is found in the joint cavity Include hip, knee, elbow joints
http://www.argosymedical.com/Skeletal/samples/animations/Synovial%20Joints/index.htmlhttp://www.argosymedical.com/Skeletal/samples/animations/Synovial%20Joints/index.html
Features of Synovial Joints • Articular cartilage (hyaline cartilage) covers the ends of bones • A fibrous articular capsule encloses joint surfaces • A joint cavity is filled with synovial fluid • Ligaments reinforce the joint
Structures Associated with the Synovial Joint • Bursae—flattened fibrous sacs • Lined with synovial membranes • Filled with synovial fluid • Not actually part of the joint • Tendon sheath • Elongated bursa that wraps around a tendon • Ligament • reinforce articular capsule
http://www.argosymedical.com/Skeletal/samples/animations/Aging%20Bone/index.htmlhttp://www.argosymedical.com/Skeletal/samples/animations/Aging%20Bone/index.html
The Synovial Joint Fluid filled synovial membrane sacs Reinforce articular capsule Covers the ends of bones Lines the articular capsule Figure 5.29
Types of Synovial Joints Sliding movements in one or two planes (uni-or biaxial Allows movement in one plane (uniaxial) uniaxial Intercarpal (between carpal bones) Elbow (humerus /ulna) Interphalange(between phalanges) Ulna / Radius Atlas/axis Figure 5.30a–c
Types of Synovial Joints biaxial biaxial multiaxial • Metacarpal bones/ proximal phalanges (knuckles) • Forearm bones/ wrist • Skull/ vertebral column • Wrist joint Thumb metacarpal and trapezium (a carpal) • Shoulder joint • Hip joint Figure 5.30d–f
Hip vs Knee Joint • Hip joint is more stable than the knee joint • Hip • Is a multiaxial joint • Allows movement in all directions Knee allows movement in one plane (uniaxial)
Muscles and Body Movements • Movement is attained due to a muscle moving an attached bone • Muscles are attached to at least two points • Origin • Attachment to a moveable bone • Insertion • Attachment to an immovable bone
Muscles and Body Movements Figure 6.12
Types of Ordinary Body Movements • Flexion • Decreases the angle of the joint • Brings two bones closer together • Typical of hinge joints like knee and elbow • Extension • Opposite of flexion • Increases angle between two bones
Types of Ordinary Body Movements Figure 6.13b
Types of Ordinary Body Movements • Rotation • Movement of a bone around its longitudinal axis • Common in ball-and-socket joints • Example is when you move atlas around the dens of axis (shake your head “no”)
Types of Ordinary Body Movements • Abduction • Movement of a limb away from the midline • Adduction • Opposite of abduction • Movement of a limb toward the midline
Types of Ordinary Body Movements • Circumduction • Combination of flexion, extension, abduction, and adduction • Common in ball-and-socket joints
Special Movements • Dorsiflexion • Lifting the foot so that the superior surface approaches the shin • Plantar flexion • Depressing the foot (pointing the toes)
Special Movements • Inversion • Turn sole of foot medially • Eversion • Turn sole of foot laterally
Special Movements • Supination • Forearm rotates laterally so palm faces anteriorly • Pronation • Forearm rotates medially so palm faces posteriorly
Special Movements • Opposition • Move thumb to touch the tips of other fingers on the same hand
Inflammatory Conditions Associated with Joints • Bursitis—inflammation of a bursa usually caused by a blow or friction • Tendonitis—inflammation of tendon sheaths • Arthritis—inflammatory or degenerative diseases of joints • Over 100 different types • The most widespread crippling disease in the United States
Clinical Forms of Arthritis • Osteoarthritis • Most common chronic arthritis • Probably related to normal aging processes • Softening, fraying and eventual breakdown of cartilage leading to bone spurs (excess bone tissue) • Rheumatoid arthritis • An autoimmune disease—the immune system attacks the joints • Symptoms begin with bilateral inflammation of certain joints • Often leads to deformities
Clinical Forms of Arthritis • Gouty arthritis • Inflammation of joints is caused by a deposition of uric acid crystals from the blood • Can usually be controlled with diet
Skeletal Changes Throughout Life • Osteoporosis • Bone-thinning disease afflicting • 50% of women over age 65 • 20% of men over age 70 • Disease makes bones fragile and bones can easily fracture • Vertebral collapse results in kyphosis (also known as dowager’s hump) • Estrogen aids in health and normal density of a female skeleton
Skeletal Changes Throughout Life Figure 5.34
Skeletal Changes Throughout Life Figure 5.35
Dislocation of joint A dislocation is a separation of two bones where they meet at a joint. A dislocated bone is no longer in its normal position, which may result in damage to ligaments, nerves, and blood vessels. Dislocation of the shoulder joint is common and occurs when the top part of arm bone slips out of its socket Radial dislocation may be caused by a sudden pull on a child's arm or hand. For first aid, immobilize the arm and take the child to the doctor's office or emergency room.