BONESBONES

The SkeletonThe Skeleton

-Contains approx. 206 bones.-Contains approx. 206 bones.

-Main function: rigid framework for support, -Main function: rigid framework for support, protection, and storage.protection, and storage.

-The human skeleton is divided into two parts:-The human skeleton is divided into two parts:

1. axial (skull, ribs, spine, sternum)1. axial (skull, ribs, spine, sternum)

2. appendicular (everything else)2. appendicular (everything else)

Bone StructureBone Structure

Bone Marrow --- Red and YellowBone Marrow --- Red and Yellow Red Marrow --- Produces red blood cells & Red Marrow --- Produces red blood cells &

certain types of white blood cells.certain types of white blood cells.

Yellow Marrow --- Consists of fat cells & Yellow Marrow --- Consists of fat cells & serves as energy storage.serves as energy storage.

Bones ContinuedBones Continued

Periosteum --- Membrane that contains a network Periosteum --- Membrane that contains a network of blood vessels which supplies nutrients. (Outer of blood vessels which supplies nutrients. (Outer layer of the bone.)layer of the bone.)

Compact bone --- Allows the bone to endure a Compact bone --- Allows the bone to endure a large amount of stress it receives upon impact.large amount of stress it receives upon impact.

Spongy Bone - Network of connective tissue.Spongy Bone - Network of connective tissue.

Bone develops from Bone develops from cartilage.cartilage.

Cartilage is a tough, flexible connective Cartilage is a tough, flexible connective tissue.tissue.

Cartilage will eventually harden during Cartilage will eventually harden during fetal development in a process called fetal development in a process called ossification.ossification.

JointsJoints

JointsJoints are places where two bones meet. are places where two bones meet.

Joints are held together by Joints are held together by ligamentsligaments, tough bands , tough bands of connective tissue.of connective tissue.

Bursae help to absorb shock & keep bones from Bursae help to absorb shock & keep bones from rubbing against each other.rubbing against each other.

Tendons attach muscle to bones.Tendons attach muscle to bones.

Hinge JointHinge Joint

Found in your elbow. Found in your elbow. Allows you to move Allows you to move arm forward & arm forward & backward. Like a backward. Like a door.door.

Gliding JointGliding Joint

Allows bones to slide Allows bones to slide over one another. over one another. Example are the Example are the joints between the joints between the small bones of your small bones of your feet. Allows your foot feet. Allows your foot to flex when you walk.to flex when you walk.

Pivot JointPivot Joint

Forms the top 2 Forms the top 2 vertebrae in your vertebrae in your neck. Allows you to neck. Allows you to move your head side move your head side to side. (Saying “no”).to side. (Saying “no”).

Ball & Socket JointBall & Socket Joint

Found in your Found in your shoulder or hip. shoulder or hip. Allows you to move Allows you to move your arm up & down, your arm up & down, forward & backward, forward & backward, & rotate in a complete & rotate in a complete circle.circle.

Saddle JointSaddle Joint

Found at the base of each thumb, allows Found at the base of each thumb, allows you to rotate your thumbs and helps you you to rotate your thumbs and helps you grasp objects with your hand.grasp objects with your hand.