Ass. Prof. Faculty of Medicine Essentials of Human Anatomy The Skeletal System 4 Joints of the Skeletal System Chapter 5 Dr Fadel Naim Ass. Prof. Faculty of Medicine IUG 1

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

Naming of Joints Usually derived from the names of the articulating bones.

Classification of Joints Fibrous Joints dense connective tissues connect bones between bones in close contact synarthrotic immovable amphiarthrotic slightly movable diarthrotic freely movable Cartilaginous Joints hyaline cartilage or fibrocartilage connect bones Synovial Joints most complex allow free movement

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

Fibrous Joints Suture 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 2 Types Synchondrosis Symphysis 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

General Anatomy of Synovial Joints Basic features: articular capsule joint cavity synovial fluid articular cartilage ligaments nerves blood vessels

General Anatomy of Synovial Joints – Accessory Structures Bursae fibrous, saclike structure that contains synovial fluid and is lined by a synovial membrane Fatpads often distributed along the periphery of a synovial joint act as packing material and provide some protection for the joint fill the spaces that form when bones move and the joint cavity changes shape Tendons attaches a muscle to a bone help stabilize joints

Types of Synovial Joints Classified by the shapes of their articulating surfaces Types of movement they allow uniaxial if the bone moves in just one plane biaxial if the bone moves in two planes multiaxial (or triaxial) if the bone moves in multiple planes

Types of Synovial Joints From least movable to most freely movable, the six specific types of synovial joints are: planar (gliding) joints hinge joints pivot joints condyloid (ellipsoid) joints saddle joints ball-and-socket joints

Types of Synovial Joints Ball-and-Socket Joint hip shoulder Condyloid Joint between metacarpals and phalanges

Types of Synovial Joints Gliding Joint between carpals between tarsals Hinge Joint elbow between phalanges

Types of Synovial Joints Pivot Joint between proximal ends of radius and ulna Saddle Joint between carpal and metacarpal of thumb

Types of Synovial Joints

Mobility and Stability in Joints Motion permitted ranges from none to various extensive motions. Structure determines both its mobility and its stability. more mobile = less stable

Types of Joint Movements abduction/adduction dorsiflexion/plantarflexion flexion/extension/hyperextension

Types of Joint Movements rotation/circumduction supination/pronation

Types of Joint Movements eversion/inversion protraction/retraction elevation/depression

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

Life-Span Changes Joint stiffness is an early sign of aging Fibrous joints first to change; can strengthen over a lifetime Changes in symphysis joints of vertebral column diminish flexibility and decrease height Synovial joints lose elasticity Disuse hampers the blood supply Activity and exercise can keep joints functional longer

Cycle of Life: Articulations Bone development and the sequence of ossification between birth and skeletal maturity affect joints Fontanels between cranial bones disappear Epiphysial plates ossify at maturity Older adults ROM decreases Changes in gait occur Skeletal diseases manifest as joint problems Abnormal bone growth (lipping)—influences joint motion Disease conditions can be associated with specific developmental periods

Clinical Application 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 Tendonitis An inflammation of the tendon Caused by excessive use.

Arthritis A group of inflammatory or degenerative diseases of joints that occur in various forms. swelling of the joint pain stiffness Most prevalent crippling disease in the United States. gouty arthritis osteoarthritis :A condition which results when the articular cartilage is enlarged or as deteriorated this results is a decrease in the range of movement of the joint. rheumatoid arthritis: An inflammation of a joint which is the result of an autoimmune disease

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