Chapter 8 Joints of the Skeletal System Articulations Functional junctions between bones Bind parts of skeletal system together Make bone growth possible Permit parts of the skeleton to change shape during childbirth Enable body to move in response to skeletal muscle contraction

Classification of Joints Fibrous Joints dense connective tissues connect bones between bones in close contact Cartilaginous Joints hyaline cartilage or fibrocartilage connect bones Synovial Joints most complex allow free movement

Classification of Joints Synarthrotic (Synarthroses) immovable Processes are interlocked Between skull bones Amphiarthrotic (amphiarthroses) slightly movable Pubis Symphysis Diarthrotic (diarthroses) freely movable Most joints in body

Fibrous Joints Suture Gomphosis Syndesmosis 3 Types Syndesmosis a sheet or bundle of fibrous tissue connects bones amphiarthrotic lies between tibia and fibula

Fibrous Joints Suture Gomphosis between flat bones synarthrotic thin layer of connective tissue connects bones Gomphosis cone-shaped bony process in a socket tooth in jawbone synarthrotic

Cartilaginous Joints Symphysis Synchondrosis 2 Types Synchondrosis bands of hyaline cartilage unite bones epiphyseal plate (temporary) between manubrium and first rib synarthrotic

Cartilaginous Joints Symphysis pad of fibrocartilage between bones pubis symphysis joint between bodies of adjacent vertebrae amphiarthrotic

Synovial Joints Diarthrotic End of long bone covered in hyaline cartilage Joint cavity filled with Synovial fluid Reduces friction Synovial membrane Joint capsule Fibrous tissue Bursae

Types of Synovial Joints Ball-and-Socket Joint Angular movement in all directions Rounded head of one bone lies in a cup like cavity of another Hip Shoulder

Types of Synovial Joints Condyloid Joint Allow movement in 2 directions Oval-shape condyle of one bone fits into a cavity or fossa of the other Capable of circumduction, flexion, abduction and adduction Between metacarpals and phalanges

Types of Synovial Joints Gliding Joint Ends of bones glide over each other Articular surfaces are almost flat between carpals between tarsals

Types of Synovial Joints Hinge Joint Allow angular motion in ONE direction Convex surface of one bone fits into concave surface of the other Allows for flexion, extension, and sometimes hyperextension elbow, knee between phalanges

Types of Synovial Joints Pivot Joint Pointed process of one bone turns within a ring formed Partly by another bone and partly by a ligament Allows for rotation atlas and axis

Types of Synovial Joints Saddle Joint Allow movement in 2 directions between trapezium and metacarpal of thumb

Types of Joint Movements Abduction drawn away from the midline of the body Adduction bring toward the midline of the body

Types of Joint Movements Dorsiflexion Flexing your foot Plantarflexion Pointing your toes

Types of Joint Movements Flexion Decrease in the angle between the bones Extension Angle is increased Hyperextension Over-extending joint beyond healthy range

Types of Joint Movements Supination turns the palm anterior Pronation turns the palm posterior

Types of Joint Movements Rotation Bone moves around a central axis Circumduction The distal end of a bone moves around a circle while the proximal end remains stationary The bone outlines a cone in the air

Types of Joint Movements Eversion sole of the foot turns away from the midline Inversion sole of the foot turns toward the midline

Types of Joint Movements Protraction moves forward on a plane parallel to the ground Retraction move backward

Types of Joint Movements Elevation Raising the shoulders Depression Lowering the shoulders

Shoulder Joint ball-and-socket head of humerus glenoid cavity of scapula loose joint capsule bursae ligaments prevent displacement very wide range of movement

Shoulder Joint

Elbow Joint hinge joint gliding joint flexion and extension trochlea of humerus trochlear notch of ulna gliding joint capitulum of humerus head of radius flexion and extension many reinforcing ligaments stable joint

Elbow Joint

Hip Joint ball-and-socket joint head of femur acetabulum of coxa heavy joint capsule many reinforcing ligaments less freedom of movement than shoulder joint

Hip Joint

Knee Joint largest joint most complex medial and lateral condyles of distal end of femur medial and lateral condyles of proximal end of tibia femur articulates anteriorly with patella modified hinge joint flexion/extension/little rotation strengthened by many ligaments and tendons menisci separate femur and tibia bursae

Knee Joint

Knee Joint Patellar ligament Popliteal ligaments Central portion of insertion for the quadriceps muscles Strengthens anterior surface Popliteal ligaments Criss-cross ligaments on the posterior surface Medial (tibial) collateral provides lateral support and is easily injured Lateral (fibular) collateral

Knee Joint Intra articular ligaments Meniscus Bursae Posterior cruciate keeps tibia from sliding backward (back part of X) Anterior cruciate keeps tibia from sliding forward (anterior part of X) Meniscus fibrocartilage that may tear and the loose parts may impede movement Bursae sac of synovial fluid found at the friction points of your body

Knee Joint Clinical Application Terrible triad Causes Treatment Tear in the medial collateral, anterior cruciate and medial meniscus Causes sports or accidents Treatment surgery with intense rehabilitation

Clinical Application Sprains Joint Disorders Sprains damage to cartilage, ligaments, or tendons associated with joints forceful twisting of joint Bursitis inflammation of a bursa overuse of a joint

Clinical Application Rheumatoid Arthritis Arthritis inflamed, swollen, painful joints Rheumatoid Arthritis Autoimmune disease body attacks its own tissue--cartilage and joint linings inflammation of the synovial membrane Treatments aimed to reduce pain and inflammation while preserving strength and mobility (rest, aspirin, steroids, exercise, etc.) bilateral small joints 1st

Clinical Application Osteoarthritis More common and less damaging Deterioration of articular cartilage and formation of bone in the joint (bone spurs) Non-inflammatory, progressive disorder Bone spurs decrease articular cavity and restrict movement Affects large weight-bearing joints Results from combination of age, irritation of the joint, and normal wear and tear Treatments are similar to Rheumatoid Arthritis

Clinical Application Gouty Arthritis Body produces excess amounts and/or is not able to excrete normal amounts of uric acid waste produced when nucleic acid is metabolized Excess uric acid reacts with sodium to form a salt called sodium urate Sodium urate crystals are deposited into soft tissues (articular kidneys, ears)

Clinical Application Gouty Arthritis Crystals irritate and wear down the cartilage eventually destroying all joint and wearing down bones If not treated bones might fuse and become immovable Affects primarily middle to older males Treatment can be successful (other two types cannot be fully treated) by controlling the uric acid production