Joints Flashcards
2 ways of classifying joints
Structural and functional
Structural classification of joints
- Fibrous
- Cartilaginous
- Bony (form when fibrous or cartilaginous joints ossify)
- Synovial
Synarthrosis
Immovable joint that can be fibrous, cartilaginous or bony
Amphiarthrosis
Slightly movable joint that can be fibrous or cartilaginous
Diarthrosis
Freely movable joint or synovial joint
Joint capsule
Surrounds the synovial joint
Articular cartilage
Provides smooth, frictionless movement
Synovial fluid
Clear, viscous solution containing proteoglycans
Functions of synovial fluid
- Lubrication
- Nutrient distribution
- Shock absorption
Meniscus
A fibrocartilage pad lying between opposing articular surfaces
Fat pads
Localised masses of adipose tissue covered by a layer of synovial membrane
Ligaments
Localised thickenings that support, strengthen and reinforce synovial joints
Sprain
When a ligament is stretched so much that some of the collagen fibres are torn, but the ligament as a whole survives and the joint is not damaged
Tendons
Connect to the fleshy part of muscles to bones that make up the joint
Bursae
Small, thin, fluid-filled pockets in connective tissue that reduce friction and act as shock absorbers
Factors that stabilise synovial joints
- Collagen fibres
- Shapes of articulating surface and menisci
- Presence of other bones, muscles, or fat pads
- Tension in tendons attached to articulating bones
Intervertebral disc
Tough outer layer of anulus fibrosus
Anulus fibrosus surrounds soft inner core nucleus polposus
Vertebral end plates cover superior and inferior surface of the disc
Intervertebral joints
- Intervertebral discs
2. Intervertebral ligaments
Structure of elbow joint
Complex hinge joint
Main joint humero-ulnar joint
What limits the degree of extension in the elbow joint?
Shape of the trochlear notch of the ulna and the olecranon
Why is the elbow joint stable?
- The bony surfaces of the humerus and ulna interlock
- A single, thick joint capsule surrounds both humero-ulnar and proximal radio-ulnar joints
- Strong ligaments reinforce joint capsule
Function of knee joint
Transfers weight from femur to tibia
Medial and lateral menisci
Lie between femoral and tibial surfaces to cushion, change shape and provide lateral stability.
Why is a complete dislocation of the knee very rare?
Seven major ligaments stabilise the knee joint
Shoulder joint
Ball and socket diarthrosis formed by articulation of humerus with glenoid cavity of scapula
Hip joint
Ball and socket diarthrosis formed between acetabulum oh the hip bone and the head of the femur
Movements of hip joint
Flexion-extension, adduction-abduction, circumduction and rotation
Movement of elbow joint
Flexion-extension only
Movement of knee joint
Flexion-extension and limited rotation
Rheumatism
General term for pain and stiffness affecting the musculoskeletal system
Arthiritis
Joint inflammation and encompasses all the rheumatic diseases that affect synovial joints
What does arthritis always involve?
Damage to articular cartilages
4 major types of synarthroses
- Suture
- Gomphosis
- Synchondrosis
- Synostosis
2 major types of amphiarthroses
- Syndesmosis
2. Sympysis
Dislocation
Occurs when articulating surfaces are forced out of position
Systems interacting with skeletal system
Integumentary, muscular, cardiovascular, lymphatic, digestive, urinary and endocrine systems
