joints/articulations

joint

place where two bones come together

structural classification

based on what structure holds 2 bones together

structural classifications of joints (3)

• fibrous joints

• cartilaginous joints

• synovial joints

fibrous joints

bones are joined by fibrous cartilage

cartilaginous joints

bones are joined by cartilage

synovial joints

bones are joined by an articular capsule which creates a joint cavity containing synovial fluid

functional classification

based on how much movement occurs at that joint

functional classifications of joints (3)

• synarthrotic joints

• amphiarthrotic joints

• diarthrotic joints

synarthrotic joints

no movement

amphiarthrotic joints

some movement

diarthrotic joints

freely movable

articular cartilage

found in all synovial joints; absorbs compression so the bone won’t be crushed

• hyaline cartilage covers the opposing bone surfaces

joint/articular capsule

found in all synovial joints; surrounds the joint cavity and has two layers:

• an outer fibrous capsule continuous with the periosteum

• an inner synovial membrane

joint cavity

found in all synovial joints; cavity that contains synovial fluid

synovial fluid

found in all synovial joints; slippery fluid that occupies all free space within the joint capsule

• reduces friction between the cartilages

• distributes nutrients

reinforcing ligaments

found in some synovial joints; reinforce the joint

bursae

found in some synovial joints; small, fluid-filled pockets that contain synovial fluid to reduce friction and absorb shock

suture

joint between skull bones

• structural classification: fibrous

• functional classification: synarthrotic

• example: sutures

syndesmosis

ligament connects two bones

• structural classification: fibrous

• functional classification: amphiarthrotic

• example: ligaments connecting bone

gomphosis

a peg-in socket joint

• structural classification: fibrous

• functional classification: synathrotic

• example: teeth joints

synostosis

formed when two bones completely fuse together

• structural classification: none

• functional classification: synarthrotic

• example: fusion of ilium, ischium, and pubis

synchondrosis

hyaline cartilage joins two bones

• structural classification: cartilaginous

• functional classification: synarthrotic

• example: true rib joint

symphysis

fibrocartilage joins two bones

• structural classification: cartilaginous

• functional classification: amphiarthrotic

• example: pubic symphysis joint

synovial joints

joint capsule joins two bones

• structural classification: synovial

• functional classification: diarthrotic

• example:

ball and socket joints

mostly freely movable of the synovial joints

pivot joints

allows for rotational movement

hinge joints

allows for flexion/extension movement

gliding joints

allows for only slight sliding movements

ellipsoidal joint

allow for flexion/extension and circumduction but not rotation

saddle joint

allow for flexion/extension and circumduction but not rotation

shoulder joint

• structural type: synovial; ball and socket

• functional type: diarthrotic

• movements: lots of movement

elbow joint

• structural type: synovial; hinge

• functional type: diarthrotic

• movements: flexion/extension

atlanto-axial joint

• structural type: synovial; pivot

• functional type: diarthrotic

• movements: rotation

proximal & distal radio-ulnar

• structural type: synovial; pivot

• functional type: diarthrotic

• movements: rotation

carpometacarpal of thumb joint (thumb joint)

• structural type: synovial; saddle

• functional type: diarthrotic

• movements: flexion/extension and circumduction

metacarpophalangeal joint (knuckle joint)

• structural type: synovial; saddle

• functional type: diarthrotic

• movements: flexion/extension and circumduction

hip joint

• structural type: synovial; ball and socket

• functional type: diarthrotic

• movements: lots of movement

knee joint

• structural type: synovial; hinge

• functional type: diarthrotic

• movements: flexion/extension

intercarpal & intertarsal joints

• structural type: synovial; gliding/plane

• functional type: diarthrotic

• movements: gliding movements