Joints Flashcards
Functions of Joints (Articulations)
1) Bind parts of the skeleton together
2) Allow for bone growth
3) Permit parts of the skeleton to change shape during childbirth
4) Enable the body to move in response to skeletal muscle contraction
Classification of Joints
- Structural
- Functional
Structural Classifications
- Fibrous joints
- Cartilaginous joints
- Synovial joints
Fibrous joints
dense connective tissue connecting bones in close contact
Cartilaginous joints
hyaline or fibrocartilage connecting bones
Synovial joints
most complex, widest range of movement; joint cavity contains synovial fluid; DIATHROTIC
Functional classification
- Synarthrotic
- Amphiarthrotic
- Diathrotic
Synarthrotic
immovable joints
Amphiarthrotic
slightly movable
Diathrotic
freely movable
Fibrous joints (types)
- Syndesmosis
- Suture
- Gomphosis
Syndesmosis (Fibrous, description)
- sheet or bundle of fibrous tissue that connects bones
- AMPHIARTHROTIC
Syndesmosis (Fibrous, example)
between radius and ulna; between tibia and fibula
Suture (Fibrous, description)
- between flat bones
- SYNARTHROTIC
- thin layer of CT connects bones until they ossify
Suture (Fibrous, example)
b/w bones of upper skull
Gomphosis (Fibrous, description)
- cone-shaped bony process in socket
- SYNARTHROTIC
Gomphosis (Fibrous, example)
tooth in jaw
Cartilaginous joints (types)
- Synchondrosis
- Symphysis
Synchondrosis (Cartilaginous, description)
- bands of hyaline cartilage uniting bone
- SYNARTHROTIC
Synchondrosis (Cartilaginous, example)
epiphyseal plate; between manubrium and 1st rib
Symphysis (Cartilaginous, description)
- pad of fibrocartilage between bones
- AMPHIARTHROTIC
Symphysis (Cartilaginous, example)
pubis symphysis; intervertebral discs
Synovial joints (description)
- all are DIARTHROTIC
- joint cavity contains SYNOVIAL FLUID within a synovial membrane (reduces friction)
- surrounded by a joint capsule (fibrous layer) for support
Synovial joints (types)
- Ball-and-Socket
- Condyloid
- Gliding/Plantar
- Hinge
- Pivot
- Saddle
Ball-and-Socket Joint (example)
hip; shoulder
Condyloid Joint (example)
b/w metacarpals and phalanges
Gliding/Plantar Joint (example)
b/w carpals; b/w tarsals
Hinge Joint (example)
elbow; b/w phalanges
Pivot Joint (example)
b/w atlas and axis; b/w proximal ends of the radius and ulna
Saddle Joint (example)
b/w carpal and metacarpal of the thumb
Shoulder Joint
- Ball-and-Socket
- b/w head of humerus and glenoid cavity of scapula
- loose joint capsule with ligaments to prevent displacement
- widest range of movement
Elbow Joint
- Hinge joint (humeroulnar)
- Gliding/Hinge joint (humeroradial)
- Pivot joint (radioulnar)
- Flexion, extension, rotation (supination and pronation)
Hip Joint
- Ball-and-Socket
- b/w head of femur and acetabulum of coxa
- heavy joint capsule with many reinforcing ligaments
- less freedom of movement than shoulder
Knee Joint
- largest, most complex joint (very vulnerable to injury)
- b/w condyles on distal end of femur and condyles on proximal end of the tibia
- femur articulates anteriorly with patella
- includes bursa to prevent friction
- modified hinge joint
- flexion, extension, little rotation
- strengthened by many ligaments
Anterior Cruciate Ligament (ACL)
- comes between condyles of the tibia (posterior to anterior connection)
- stabilizes the knee joint by preventing excessive forward movement of the tibia and limits rotational movements
Posterior Cruciate Ligament (PCL)
- upside down Y
- stabilizes the knee joint by preventing the tibia from slipping too far back in relation to the femur
Medial (Tibial) Collateral Ligament (MCL)
- runs from the inside surface of the upper tibia to the inner surface of the lower femur
- stabilizes the knee joint by preventing the leg from extending too far inward
Lateral (Fibular) Collateral Ligament (LCL)
- runs from the inside surface of the upper fibula to the inner surface of the lower femur
- stabilizes the knee joint by preventing the leg from extending too far outward
Meniscus
- between the femur and the tibia (looks like two cups, medial and lateral)
- provide increased stability, distribute weight load, absorb shock, and provide lubrication of the knee joint (reduce friction)
