Other structures associated with synovial joints

ligaments

bands of regular connective tissue

function of ligaments

stabilize the joint by connecting bone to bone

limit excessive or abnormal movement

types of ligaments

extracapsular - outside the joint capsule

intracapsular - inside the capsule but outside the synovial cavity

articular discs (menisci)

pads of fibrocartilage inside the joint

functions of articular discs

improve the fit between articulating bones

provide shock absorption

help distribute weight across the joint

allow separate movements within the joint

reduce wear and tear by spreading synovial fluid

Labrum

fibrocartilage rim in ball-and-socket joints (ex; shoulder, hip)

Function of labrum

deepens the socket

provides extra stability for the joint

Bursae

flattened bags of synovial fluid-like “fluid-filled pillows”

not part of the joint itself but closely associated

function of bursae

reduce friction where ligaments, tendons, muscles, skin, or bones rub together

tendon sheaths

elongated bursae that wrap around tendons

function of tendon sheaths

reduce friction on tendons that move in tight spaces or over bones

Function of nerves

detect pain, monitor joint position and stretch

Capillary beds function

supply filtrate that becomes synovial fluid