Exam 3: Articulations Flashcards
Amphiarthrosis
Restricted movable joints:
- fibrous or cartilaginous connections
- more moveable than synarthrosis
- stronger than freely movable joints
Two types:
- Syndesmosis = bones connected by ligaments (btwn radius and ulna)
- Symphysis = bones separated by fibrocartilage (pubic symphysis)
Diarthrosis (synovial joints)
Freely movable joints:
- at ends of long bones
- within articulate capsules
- lined with synovial membrane
- subdivided by type of motion
Structure of synovial joints
- Articular capsules
- Articulate cartilages:
- pads articulating surfaces
- prevents bones from touching - Synovial fluid:
- contains slippery proteoglycans
- secreted by fibroblasts within synovial membrane
FUCNTION = lubrication, nutrient distribution, and shock absorption - Cartilages (accessory structure):
- cushions the joint; fibrocartilage meniscus - Fat pads (accessory structure):
- protects articular cartilages - Accessory ligaments (accessory structure):
- support, strengthen joints - Tendons (accessory structure):
- attach to muscles around joint, support joint - Bursae (accessory structure):
- pockets of synovial fluid
- cushion areas where tendons or ligaments run
Types of synovial joints
Gliding Hinge Pivot Ellipsoidal Saddle Ball-and-socket
Synarthrosis
Immovable joints:
- fibrous or cartilaginous connections
- may fuse over time
- are very strong
- edges of bones may touch or interlock
Two types:
- Suture = bones interlocked, are bound by dense fibrous connective tissue, and found only in SKULL
- Synchondrosis = a cartilaginous bridge btwn 2 bones (ex: vertebrosternal ribs and sternum)
Gliding joints
Flattened or slightly curved faces
Limited motion
Ex: acromioclavicular and claviculosternal joints
Hinge joints
Angular motion
Motion in 1 plane (monoaxial)
Ex: elbow, knee, ankle, and interphalangeal joints
Pivot joints
Rotation only
Motion in 1 plane (monoaxial)
Ex: atlas/axis
Ellipsoidal joints
Oval articular face within a depression
Motion in 2 planes (biaxial)
Ex: radiocarpal joint
Saddle joints
Two concave faces
Motion in 2 planes (biaxial)
Ex: first carpometacarpal joint
Ball-and-socket
Round articular face in a depression
Motion in 3 planes (triaxial)
Ex: shoulder and hip joint
Flexion (angular motion)
Decreases the angle btwn elements
Ex: bending forearm
Extension (angular motion)
Increases angle btwn elements
Ex: straightening forearm
Abduction (angular motion)
Ab = from
Moving limb away from longitudinal body axis
Ex: raising arm laterally
Adduction (angular motion)
At = to
Moving limb toward longitudinal axis
Ex: fingers together
Circumduction (angular motion)
Circular motion without rotation
Ex: circle shoulder, hip
Rotation
Turning of a bone around its long axis
Supination (rotation)
Lateral (outward) rotation: away from axis
Ex: Palm faces anteriorly
Pronation (rotation)
Medial (inward) rotation: toward axis
Ex: rotation of forearm, radius over ulna
Inversion and eversion (special movement)
Inversion: twists sole of foot medially
Ex: sole of foot in
Eversion: twists sole of foot laterally
Ex: sole of foot out
Depression and elevation (special movement)
Depression: moves in inferior direction (down)
Ex: jaw down
Elevation: moves in superior direction (up)
Ex: jaw up
The knee joint
Largest and most complex joint
Transfers weight from femur to tibia
Articulations of the knee joint
Two femur-tibia Articulations:
- at medial and lateral condyles
- btwn patella and patellar surface of femur
Menisci of the knee
Medial and lateral menisci:
- fibrocartilage pads
- at femur-tibia articulations
- cushion and stabilize joint
- give lateral support
Locking knees
Standing straight: “locks” knees by jamming lateral meniscus between tibia and femur
Ligaments of the knee joint
- Patellar ligament (anterior)
- Anterior and posterior cruciate ligaments (inside joint capsule)
- tibial collateral ligament (medial)
- fibulae collateral ligament (lateral)
Also:
- quadriceps tendon
- medial and lateral meniscus
- medial and lateral condyles
- patellar surface
