1 Articulations: Joints of the Skeletal System Joints or Articulations: – Functional junctions where bones meet – 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

2 Classification of Joints Classified according to their structure and function: 1. Fibrous Joints dense connective tissues connect bones between bones in close contact 2. Cartilaginous Joints hyaline cartilage or fibrocartilage connect bones 3. Synovial Joints most complex allow free movement Range of motion permitted is used for functional classification: 1. synarthrotic immovable 2. amphiarthrotic slightly movable 3. diarthrotic freely movable also called a synovial joint

3 Fibrous Joints 3 Types 1. Syndesmosis 2. Suture 3. Gomphosis 1. Syndesmosis – a sheet or bundle of fibrous tissue connects bones – lies between tibia and fibula – amphiarthrotic

4 Fibrous Joints 2. Suture – between flat bones – thin layer of connective tissue connects bones – synarthrotic 3. Gomphosis – cone-shaped bony process in a socket – tooth in jawbone – synarthrotic

5 Cartilaginous Joints 2 Types 1. Synchondrosis 2. Symphysis 1. Synchondrosis – bands of hyaline cartilage unite bones – epiphyseal plate (temporary) – between manubrium and first rib – synarthrotic

6 Cartilaginous Joints 2. Symphysis pad of fibrocartilage between bones pubis symphysis joint between bodies of adjacent vertebrae amphiarthrotic

7 Synovial Joints – diarthrotic – joint cavity filled with synovial fluid – joint capsule – synovial membrane – bursae

8 Types of Synovial Joints 1. Ball-and-Socket Joint hip shoulder 2. Condyloid Joint between metacarpals and phalanges

9 Types of Synovial Joints 3. Gliding Joint between carpals between tarsals Temporomandibular joint 4. Hinge Joint elbow knee between phalanges

10 Types of Synovial Joints 5. Pivot Joint between proximal ends of radius and ulna Between axis and atlas 6. Saddle Joint between carpal and metacarpal of thumb

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

12 Types of Joint Movements rotation/circumduction supination/pronation

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

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

15 Shoulder Joint

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

17 Elbow Joint

18 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

19 Hip Joint

20 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

21 Knee Joint

22 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, therefore activity and exercise can keep joints functional longer

Clinical Application Osteoarthritis –also called Degenerative Joint Disease –most common form of noninflammatory arthritis –Degeneration and fracturing of articular cartilage and by abnormal formation of new bone (osteophyte) Arthritis – inflammatory joint disease –Rheumatic diseases that affect synovial joints –inflamed, swollen, painful joints Rheumatoid Arthritis (RA) –Systemic autoimmune disease –Chronic inflammation of many different tissues and organs, but generally attacks joints first and most severely 23

Osteoarthritis Ulnar deviation: RA

Clinical Application Gout (an inflammatory arthritis) –Metabolic disorder with a build up of uric acid around small joints –Swelling, tenderness, or pain appears in fingers, wrists, elbows, ankles and knees. –Treated with Zyloprim to inhibit the uric acid synthesis in the body Bursitis –Inflammation of bursa –Caused by prolonged pressure, excessive or repetitive exercise or sudden trauma to a joint 25

Clinical Application Sprain o damage to cartilage, ligaments, or tendons associated with joints o forceful twisting or torsion or severe stress to a joint Dislocation –Displacement of articular surfaces –Strong blow to joint or ligament laxity –Subluxation is a partial dislocation 26

Clinical Application Hypermobility –Increased range of motion (ROM) of a joint –Repetitive injury Hypomobility –Decreased ROM of a joint –Joint immobilization Frozen Shoulder (Adhesive Capsulitis) –Progressive loss of ROM External Rotation, Abduction, Internal Rotation –Pain from swelling and loses function –Idiopathic – cause may be unknown or arise suddenly 27