Skeletal System

The Skeleton is the name given to the collection off bones in the body and the tissues that connect them.

The skeleton has 5 major functions. It protects our vital organs such as the brain, the heart, and the lungs It gives us structure. Without it we would just be a blob of blood and tissue on the floor. It allows us to move. Because our muscles are attached to our bones, when our muscles move, they move the bones.

Functions It stores calcium. Which keeps bones and teeth hard. It makes Red and White blood cells

Skeleton Facts When you were born, your skeleton had close to 350 bones By the time you become an adult, you will only have around 206 bones This is because, as you grow, some of the bones fuse together to form one bone such as the skull. Our bones are 5 times stronger than steel •. •

Skeleton Facts The smallest bones in the body are found in the ear. (3mm) The longest bone in the body is the femur Over half the body's bones are in the hands and feet. As your bones grow, you get taller. Girls usually stop growing around age 16, and boys around age 18.

Organization of the Human Skeleton • Your skeleton is made up of two parts; the axial skeleton and the appendicular skeleton. Green = Axial Purple = Appendicular

Colour the axial and appendicular parts of the skeleton Axial skeleton protects the organs of your body

Appendicular skeleton allows movement

The Axial Skeleton • Skull 29 • vertebral column 24 • ribs (12 pairs) 24 • Sternum 1 • Sacrum 1 • Coccyx 1 • Total 80 Green Area

The Appendicular Skeleton • pectoral girdles (2 x 2) 4 • Arms (3 x 2) 6 • Wrists ( 8 x 2) 16 • hands (19 x 2) 38 • pelvis 2 • legs (4 x 2) 8 • ankles (7 x 2) 14 • feet (19 x 2) 38 • total 126 Purple Area

There are Four Main types of bone Flat: like those found in the skull; provide protection for soft tissues and points for muscle attachment Long: found in the arms and legs; provide strength and support Short: found in the wrists and ankles; provide flexibility Irregular: backbone, middle ear; have shapes related to a specialized function

Flat Long Irregular Short

Bones • Bones get their strength and rigidity from hard deposits of minerals such as calcium and phosphate. • Bones are strong but light because they are hollow and filled with a substance called Bone Marrow.

Bone Marrow • is a spongy, fatty tissue that houses stem cells. These cells can transform themselves into platelets, white or red blood cells that are needed for immunity and circulation. • Red marrow is found in some flat bones (hip, skull, vertebrae and rib bones) Yellow marrow is a fat tissue storage site in the middle of some longer bones.