The Skeletal System
The Skeletal System is a large body system that is made up of mostly bones, it includes all of our skeleton. When a human is born they have more than 300 bones in their body which fuse together as you grow, however as a baby your bones are mostly made up of cartilage, a material that is more flexible than bone, making you more vulnerable to bone damage when you're a baby. As an adult you have around 250 bones and their actually mostly bone now which means your less vulnerable to bone breakage (Yay). Inside most bones is bone marrow, there are 3 types of bone marrow, they are; Red bone marrow which makes red blood cells and platelets, white bone marrow which makes white blood cells, and yellow bone marrow which stores a lot of fat for when you need extra energy, sort of like an emergency energy reserve. That is the skeletal system.