The Wonderful World of Joints!

What holds your joints together and keeps them connected as you move?

Bones come together at joints.

Joints are wrapped with ligaments that hold the joint together.

Cartilage, a soft type of protein, acts as padding and helps to decrease friction where bones connect.

Damaged cartilage causes pain and arthritis!

Arthritis: damaged cartilage in joints

Types of JointsJoints are places

where bones connect.

Joints increase skeletal flexibility

FFF (Form Follows Function) The configuration of a joint (form) determines the degree and direction of possible motion (function).

Immovable joints: no motion between the bonesCranium sutures

Slightly movable/semi-movable jointsRibs to sternumProvide flexibility

during breathing

Freely Movable Joint typesHinge joint: An

angle change in one planeElbowKneeFingers

Like a door hinge, opening and closing

Freely Movable Joint typesBall and

Socket Joint: circular rotational motionHipShoulder

Like a “joy stick”

Provides maximum mobility

Freely Movable Joint typesPivot JointSide to side

rotation, like turning a doorknobElbow (

http://www.shockfamily.net/skeleton/ARM.MOV)

Neck

Freely Movable Joint types: Glide Joint

Slide back and forth across connecting surfaceMetacarpal/

metatarsal (hands, feet)

vertebrae

Reading review: bone typesLong bones

Arms, legsShort bones

Feet, handsIrregular bones

spineFlat bones

Ribs, skull

Reading review: Joints improve body flexibility

Immovable: Skull and pelvisSlightly movable: ribs to sternumFreely movable: large range of motion

Hinge: angular movement Elbow, knee

Pivot: side to side rotational motion elbow, neck

Ball and socket: circular rotation Shoulder, hip

Glide: small back and forth slide Spine, wrists, ankles

questionsWhat questions do you have about bones and

bone growth? Growth platesOsgood schlattersBone, tendon, ligament deal...when does that

happen?What do other organisms use?

WHY? Bird bones are easier to

break. Why?Some fish, like sharks

and skates, do not have calcium in their bones –instead, their bones are made entirely of cartilage protein-–like the cartilage in your nose and ears. Why is this an advantage? Why is it a disadvantage?