1. The Skeletal System
Section 1.2

2. Components The skeletal system is a living organ system.
Bones are organs, and there are 206 in the human skeleton.
The skeletal system consists of bones, cartilage, and connective tissue that holds bones together.

3. Functions Support and protect body parts
Ribs protect heart and lungs.
Skull protects brain.
Vertebrae protect spinal chord
Storage of minerals and fat needed by our bodies
Movement of our bodies when pulled on by skeletal muscles
Blood cell formation
Blood cells are produced by marrow in some bones

4. Bone Structure Made of connective tissue and minerals Compact bone
Rigid and dense with small blood vessels
Spongy bone
Many open spaces, most of a bone’s strength and support
Marrow
Red marrow- produce red and white blood cells
Yellow marrow- stores fat in central cavity of long bones

5. Joints Spot where 2 or more bones meet
Different types of joints allow different kinds of movement
Ligaments- connective tissue that holds bones to each other at joints
Cartilage- connective tissue that covers the ends of many bones to cushion joints
Most bones started out as cartilage.
Tip of nose and top of ears are still cartilage

6. Fun fact
Humans have a tailbone