1.5 joints

what cell type makes up cartilage?

chondrocytes

what materials make up cartilage?

chondrocytes, collagen (& other organic matrix components) & water

most common joint

synovial joint

label this

synovial membrane

surrounds joint space of synovial joint
secretes synovial fluid

fibrous joint capsule

strengthens synovial joint

a healthy shoulder in arthroscopy should be:

smooth & white

what can a diseased shoulder joint look like in an arthroscopy?

rough & bumpy with detached tissue, synovial fluid becoming discoloured

what is the function of articular (hyaline) cartilage?

providing smooth gliding surface (lubrication)
shock absorption (stiff to compression)
distributes load & protects underlying bone

articular cartilage:
what is the vasculature like?
what does this mean for healing properties?

no vasculature/nerve supply
limited capacity for healing/repair

spot the chondrocytes

dark pink dots within white spaces = chondrocytes

synovial fluid

clear/straw coloured
contains hyaluronic acid
provides lubrication, shock absorption & nutrient/waste transport

menisci

accessory joint structure for shock absorption (not every joint has this)
c-shaped piece of tough, rubbery cartilage

bursae

fluid filled sack, cushioning tendon as it pushes against sesamoid bone

tendon sheath

like bursae but wrap around tendon where they pass over joints

synsarcosis joint

only muscular attachment (e.g. scapula onto ribcage)

fibrous joint

least mobile joint, connecting neighbouring bones w little to no movement (e.g. flat bones within skull)

cartilaginous joints

some motion, but not too much (e.g. pelvis allowing child to pass through canal, intervertebral disks)

multi-axial joint example

ball & socket

bi-axial joint example

condyloid
saddle

uni-axial joint example

pivot
hinge

gliding joint example

planar

pivot joint

peg fitted within ring, peg rotates around ring (or vice versa)

hinge joint

one articular surface convex, other is concave, usually a 'notch' is present to limit motion

condylar joint

convex surface w corresponding concave cavity

saddle joint

two surfaces - convex in one direction, concave in the other at right angles

joint motion

when two or more bones meet to allow movement

what does a greater range of movement increase? why?

greater the range of movement = higher the risk of injury
strength of the joint is reduced

moment arm

length between joint axis and the line of force acting on the joint