Joint classes Flashcards
Synovial joints
Most free moving joints but also for control, found in most limbs
FEATURES
* Has a different supporting tissues and cartilage depending on the bony congruence of the joint
*The bones determines its range of movement and control
What does joint structure determine?
The amount and direction of movement
What would happen if the pubic symphysis was fibrous?
Wouldn’t be able to walk as the swaying movement as we walk if aided by the symphysis/ can’t bend over
Important structures of synovial joints
- Bone ends - made of at least 2 bones maybe 3, the ends determine how many supporting structures are needed, some space between the bones
- Hyaline cartilage
*Joint capsule
*Joint cavity - between sunovial membrane and bones, has synovial fluid, is a potential space for any extra movement if needed - Synovial membrane
- Ligaments that are part of the joint capsule or seperate
Hyaline
Hyaline cartilage - at the articulations, provides a smooth, watery surface for smooth, frictionless movement against bones, right over the subchondral area if bone (facet)
They dont touch each other as they are seperated by a thin film of synovial fluid
Joint Capsule
surrounds the joint, continuous with the periosteum adds more strength and mobility to joint, prevents everything from leaking out
Outer layer made of DFCT and inner made of specialised cells of synovial membrane (areolar tissue) that secretes synovial fluid (has high content of HYA). Viscosity of fluid increases wiith more pressue
*Synovial fluid provides lubrication for frictionless movement and also nutrients for avas cartilage tissue through joint loading
It is tight and loose where needed i.e tight for more stability and loose for more movement. Eg shoulder joint tight at back and looser at front
Ligaments
Capsular ligs, part of joint capsule
eg knee - Medial and Lateral collateral ligaments
*MCL - femur to tibia, resists abduction of knee during movement
*LCL - femur to fibula, resists adduction of knee during movement
Intracapsular ligs, inside the joint capsule
eg cruciate ligaments in the knee, arises from the tibia
*ACL - from anterior of tibia to posterior of femur, prevents femur from sliding backwards
*PCL - from posterior of tibia to anterior of femur, prevents femur from sliding forwards
BONUS: Fibrocartilaginous pads/structures
shock absorption, weight distribution, cushion, deepen articulation, fill space
meniscii in the knee, sing. meniscus, cups femur and increases bony congruence for stability
Synovial joints cannot have…
Both high stability and high mobility, it is a tradeoff between the two
7 types of synovial joints
*Hinge
*Saddle
*Ellipsoid
*Ball and Socket
*Condyloid
*Plane
*Pivot
What influences possible movements of joints?
Ligaments and bony congruence
Range of motion
The different types of movement, depends on bone ends, congruence and ligament control + position
What are the planes and axes of movement?
Sagittal, transverse and coronal
axes - coronal plane sagittal axes
- Sagittal plane coronal axis
- Transverse plane vertical axis
Uniaxial
Biaxial
Multiaxial
depending on how much movement a joint has
Plane joint
Sliding and gliding joints, multiaxial, flat surfaces
visual: put palm of hands together and rub and rotate
egs. intercarpal and intertarsal, clavicle and manubrium
Hinge joint
Uniaxial, flexion and extension, how the bone hooks
egs interphalangeal, ankle, elbow
