Memory Bones, Muscles, LungsVersion en ligne Skeletal and Muscular System par Elizabeth Lowes INvoluntary muscle Breath OUT Leg / Thigh bone (Femur) Protects Brain Protein Protects Heart and Lungs Mineral that makes bones strong Made from Tobacco plant Longest Bone Strongest muscle Intestines Carbon Dioxide Skull Breathe IN Calcium Oxygen Cigarettes ribcage Jaw muscle Food Group that builds muscle