The Skeletal System Section 1.2

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.

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

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

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

Fun fact Humans have a tailbone