joints Flashcards
fibrous joints
limited movement, provides stability, DFCT forms ligaments which hold bones together e.g cranial sutures
cartilaginous joints
some movement - fibrocartilage holds bones together e.g. intervertebral joints.
synovial joints
free moving, most joints in appendicular skeleton, complex association of tissues and structures
what is the basic structure of synovial joints?
- at least two bone ends
- hyaline cartilage covers articulation of joints
- joint capsule wraps around the joint
- joint cavity provides potential space for movement
- synovial membrane secretes synovial fluid full of nutrients that can be pushed into avascular tissue via joint loading
- ligaments link the bone to bone
what are the 2 layers of the joint capsule and what are there functions?
outer layer of DFCT provides support and holds bones together, can be thinner or thicker depending on the need for movement
inner layer of synovial membrane secretes synovial fluid to provide nutrients to avascular tissues and lubricates the joint for smooth frictionless movement
what is a capsular ligament?
thickenings of capsules provided for joints that need more support
e.g. LCL connects femur to the fibula, restricts adduction by pulling tight if the leg tries to move towards the midline
what is a intracapsular ligament?
holds bone together in joints with additional bands of DFCT located internally to the capsule
e.g. ACL restricts posterior displacement of the femur
what are fibrocartilaginous pads??
small structures made of cartilage found in some joints (e.g. meniscus in knee) that fill space, provide cushioning and/or deepen articulations
what are two example joints that show the relationship between mobility and stability
synovial joints have lots of mobility but not much stability, fibrous joints have lots of stability but not much mobility
what determines the range of movement (ROM)
bone end shape, ligament location, body/surface contact
what are the types of axis of planes that a joint can revolve around
uniaxial (1 plane)
biaxial (2 planes)
multiaxial (3 or more planes)
what direction do axis run in, in relation to a plane
opposite, if you move down the sagittal plane your axis is in the coronal plane
the transverse plane rotates around a vertical axis (like the equator and the north and south poles)
how many types of synovial joints are there
seven different types of synovial joints
what are the features of a plane joint?
multiaxial
sliding and gliding motion
flat articular surfaces
e.g. intercarpal and intertarsal joints
what are the features of a hinge joint
uniaxial
movements are flexion and extension
e.g. ankle, elbow, interphalangeal joints
what are the features of a pivot joint
uniaxial
movement is rotation
e.g. radioulnar joints (supination and pronation) , C1-C2 vertebrae
what are the features of condylar joints
biaxial
flexion, extension and rotation (when flexed)
e.g. knee, temporomandibular joint
(condyles are the lumpy bits on the end of a bone)
what are the features of ellipsoid joints
biaxial
flexion, extension
adduction, abduction
therefore circumduction
e.g. wrist (radiocarpal) joint
what are the features of saddle joint
biaxial (+ extra on thumb)
flexion, extension, abduction, adduction
opposition in thumb
e.g. carpometacarpal joint (base of thumb
what are the features of a ball and socket joint?
multiaxial
flexion, extension, adduction , abduction
thus circumduction
rotation
e.g. shoulder and hip
