Joints

example of synovial joints

shoulder, knee, elbow, hip are large, freely movable joints

movable or synovial joints

1. 90% of the bones in our bodies are freely movable 2. these joints contain synovial fluid which is located inside a pocket called synovial membrane, this lubricates the joints 3. all the moving parts are held together by ligaments - highly movable joints, like your shoulder or knee

types of joint movement

1. abduction/adduction 2. dorsiflexion/plantar flexion 3. flexion/extension/hyperextension 4. lateral flexion 5. rotation 6. circumduction 7. supination/pronation 8. eversion/inversion 9. protraction/retraction 10. elevation/depression

slightly movable joints

1. also known as cartilaginous joints 2. the bones are separated by a cushion of cartilage, the joints between the vertebrae in the spine are cartilaginous joints 3. these bones can move a little bit, but ligaments stop them from moving to far, this is why we can bend, straighten and rotate our back but not too far

general structure of a synovial joint

1. articular cartilage 2. joint cavity 3. joint capsule 4. synovial membrane 5. synovial fluid - meniscus in knee

hip joint

1. ball and socket - head of femur and acetabulum of hip bone - heavy joint capsule - many reinforcing ligaments - variety of movement, yet less than at shoulder joint - ilio-, ishio-, and pubofemoral ligaments make joint capsule

shoulder joint

1. ball and socket - head of humerus and glenoid cavity of scapula - loose joint capsule - bursae - ligaments prevent displacement - very wide range of movement (circumduction) - rotator cuff muscles holds it in

types of synovial fluid

1. ball and socket/spheroidal joint - hip and shoulder joint 2. condylar/ellipsoidal joint - between metacarpals and phalanges; between radius and carpals 3. plane/gliding joint - b/w carpals and tarsals; b/w facets of adjacent vertebrae

synchondrosis includes

1. bands of hyaline cartilage unite bones 2. epiphyseal plate (temporary) 3. between manubrium and the first rib (costal cartilage) - ribs 2-7 usually synovial joints

suture

1. between flat bones - teeth-like projections - thin layer of connective tissue connects bones - skull - synarthritic

cemented vs. cementless

1. cemented - elderly >65 - low demand - better early fixation 2. cementless - younger - more active - better long-term fixation

gomphosis

1. cone-shaped bony process in a socket - tooth in jawbone ' - synarthritic

synarthrotic joints

1. considered immovable

fibrous joints

1. dense connective tissue connect bones - bones in close contact

diarthrotic joints

1. freely movable

elbow joint

1. hinge joint with ulna and plane joint with head of radius and humerus 2. joint capsule thickened laterally and medially- collateral ligaments 3. anular ligaments of radius allows radius to rotate - radial head dislocation (subluxation)

cartilaginous joints

1. hyaline cartilage or fibrocartilage connect bones

three classifications of joints

1. immovable or fixed joints 2. slightly movable joints 3. movable or synovial joints

lifespan changes

1. joint stiffness is an early sign of aging 2. fibrous joint first to change 3. changes in symphysis joints of vertebrae column diminish flexibility and decrease height 4. synovial joint lose elasticity 5. disuse hampers the blood supply 6. activity and exercise can keep joints functional longer

introduction of joints

1. known as articulations - functional junctions between bones - binds parts of skeletal system together - make bone growth possible - permits parts of skeleton to change shape during childbirth - enable body to move in response to skeletal muscle contraction - classified by structure and function (movement)

knee joint

1. largest joint - most complex 3 bones - medial and lateral condyles of distal end of femur - medial and lateral condyles of proximal ends of tibia - femur articulates anteriorly with patella - strengthened by many ligaments and tendons - menisci separate femur and tibia - several bursae

synovial joints

1. most complex; allows free movement

synovial joints cont.

1. most joints - all are diarthritic 2. consist of: - articular cartilage - joint capsule - synovial membrane - secretes synovial fluid

arthroplasty

1. osteoarthritis most common cause 2. hip and knee most common - 1891: used ivory to replace head of femur - 1970's: we got good at it - future: condrocyte culturing to fix arthritic joints

symphysis includes

1. pad of fibrocartilage between bones 2. pubic symphysis 3. joints between bodies of adjacent vertebrae

amphirarthrotic joints

1. slightly movable

bursae

1. small fluid-filled sac lined by synovial membrane 2. provides a cushion between bones and tendons and/or muscles around a joint

joint classification

1. structural classification: a. fibrous joints b. cartilaginous joints c. synovial joints 2. functional classification: a. synarthrotic joints b. amphirarthrotic joints c. diarthrotic joints

connective tissues include

1. tendons: connect muscles to bones 2. ligaments: are tough, elastic fibers that link bones to bones 3. cartilage: prevents the ends of bones from rubbing together at joints, its slippery surface helps to lubricate the joints

fibrous joints cont.

1. there are 3 types (synarthroses) a. syndesmosis - a sheet or bundles of fibrous tissue connecting bones - lies between tibia and fibula (interosseous membrane) - amphiarthritic b. suture c. gomphosis

immovable or fixed joints

1. there are fewer than 10 immovable joints in body - also called fibrous joints because the bones are held together by tough fibers 2. immovable joints can be found in skull and pelvis, where several bones are fused together to form a rigid structure

cartilaginous joints cont.

1. two types a. synchondrosis b. symphysis

types of synovial fluid cont.

4. hinge joint - elbow joint; b/w phalanges 5. pivot joint - b/w atlas (C1) and axis (C2) 6. saddle joint - b/w carpal and 1st metacarpal of thumb