musculoskeletal system Flashcards
Characteristics of joints
- Excellent nerve supply, can detect pain, touch, temperature, and proprioception (awareness of where joint is)
where do joints get their blood supply
- Arteries supplying joint arise from large named arteries near joints – ‘articular branches’. periarticular anastomoses are common
what can be damaged in dislocation
arteries supplying blood to joints
classification of joints
synovial, cartilaginous, fibrous. Each compromise between mobility and stability
fibrous joints
limited mobility, most stable. 2 types
2 types of fibrous joints
syndesmoses and sutures
syndesmoses
unites bones with fibrous sheet fibrous membrane eg interosseous membranes
sutures
between bones of skull, eg between fontanelles, highly stable
what are fontanelles
wide sutures in the neonatal skull, anterior, posterior and lateral. Allow the bones to slide over each other to make the head fit in birth canal
cartilaginous
fairly limited mobility, relatively stable. 2 types
2 types of cartilaginous joints
primary ‘synchondroses’ and secondary ‘symphyses’
primary. synchondroses
‘synchondroses’ bones joined by hyaline cartilage eg in long bone epiphyseal growth plate. Permit growth in length. Ossification and fusion
secondary. symphyses
‘symphyses’ strong, slightly movable, fibrocartilage eg intervertebral discs. Made of outer annulus fibrosus (fibrous ring) and inner sort nucleus pulposus (soft center). Each disc allows small movements, but all together allow a wide range
what can happen with a slipped disc
can compress spinal cord
synovial
most mobile, least stable. 2 or more bones articulating with each other
characteristics of synovial joints
- Surfaces covered in hyaline cartilage
- capsule wraps around the joint
- contains a joint cavity which contains synovial fluid (cushions, nourishes, lubricates)
- supported by ligaments, which associate with skeletal muscles and their tendons
- associated with bursae, extensions of joint cavity and prevent friction around joint
- often have special features eg articular disc in jaw
5 subtypes of synovial joints
Pivot eg rotating head. Plane, minimal movement in one place. Hinge, reasonable movement in one place. Biaxial, range of movement in one plane and less in another. Ball and socket, good range, multi-axial movement
mobility/stability
type of joint dictates. - In synovial joint. The shape and fit are important for mobility and stability
- Eg shoulder has a shallow socket = more movement but less stable
- While the hip socket has a deeper socket therefor a tighter fit = less mobility but more stable
direction of movement
shape of articular surface determines this. Example, shallow socket of the glenoid fossa of the scapula – permits circumduction of the shoulder
ligament injury/ slipped disc
- Ligament injury or slipped disc still allows normal anatomical relationship w each other
subluxation
- Subluxation = reduced area of contact between surfaces but still kind of work
dislocation
complete loss of contact between articular surfaces. Common = shoulder, elbow, interphalangeal. And sometimes during pregnancy under influence of hormone relaxin the pubic symphysis can too
skeletal muscle
- They provide movement, found under deep fascia of skin they have a tough fibrous connective tissue covering
types of skeletal muscle
circular, usually cover an opening. Pennate, feather like with fibers spreading out. Quadrate, have 4 sides eg the abs. flat, aponeurosis. Fusiform, spindle shape eg biceps
