The Skeletal System

1. The Skeletal System 6th Grade Health

2. Learning Target: I will learn about the skeletal system. Success Criteria: To be successful I will know: • The 3 major jobs of the skeletal system. • The 2 minor jobs of the skeletal system. • How many bones are in the adult human skeleton. • Where over half of them are located. • What shape the human backbone is. • The names of the bones, their functions, and be able to locate and label them on a skeletal picture.

3. The Skeleton is the name given to the collection of bones that holds the rest of our body up. Our skeleton is very important to us. It does three major jobs. • It protects our vital organs such as the brain, the heart, and the lungs. • It gives usourshape that we have. Without our skeleton, 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, and we move.

4. The skeletal system also has two minor jobs. • It makes blood cells so the rest of the body can use them. • It is a warehouse for fat cells, calcium, and other minerals.

5. Words to Know… vertebrae: the backbone cranium: the skull ligament: connective tissue that connects bones to other bones tendon: connective tissue that connects bones to muscles joint: place where two bones meet cartilage: flexible tissue that protects bones and acts as a shock absorber

6. When you were born, your skeleton had around 350 bones. • By the time you become an adult, you will only have 206 bones. • As you grow, some of the bones join together (fuse) to form one bone.

7. Hands & Feet Each hand has twenty-seven separate bones. These are connected with muscles and tendons. Hand bones are also called the metacarpus. Just like the foot, the bones in the fingers are called phalanges.

8. Hands & Feet The seven bones in the ankle are called tarsal bones. The main part of the foot is made of metatarsal bones. Phalanges are the bones in the toes. The arch in the foot helps to support the body's weight.

9. Over half your bones are found in your hands and feet. There are 26 bones in each foot and 27 in each hand. Look, Mom, no hands....no feet!!

10. What about my legs? . • Another name for the femur is the thigh bone. The femur extends from the hip joint to the knee This is the longest bone in the body. • The tibia and fibula are the bones of the lower leg. As it helps to support the body's weight, the tibia is the strongest bone in the body. The thinner bone is the fibula and helps to control the movement of the ankle. Another name for the tibia is the shin bone. • The bone that is at the middle of the leg is the patella, or knee cap.

11. What about the ribs? • The breastbone, or the sternum, is linked to the bones which make up the ribs. The sternum is a flat bone that is about 6 inches long. • Most people have 12 pairs of ribs. The ribs are connected to the sternum by cartilage. This makes the ribs more flexible, which is necessary during breathing. • The first seven pairs of ribs are attached directly to the breastbone. • The eighth, ninth and tenth pairs are attached to the sternum by a cartrilage band. The last two pairs of ribs are not attached to the sternum or cartilage. The last five pairs of ribs are called false ribs.

12. You need your ribs for protection!! Your rib cage is made up of 12 vertebrae, 24 ribs and a breastbone. It protects your heart and lungs from knocks and bumps.

13. THE BACK The spine is the central support for the body. Another word for the spine is the backbone. The spine is made of separate irregular bones called vertebrae. The vertebrae are made up of spongy or cancellate bone surrounded by a layer of compact bone. In between each vertebrae is a layer of cartilage that keeps the bones from rubbing against each other. There are twenty six vertebrae in the spine. Although each vertebrae can only move a little bit, the total spine is very flexible. The spine of a human being is curved. Most other mammals have a straight spine. The curves allow the spine to support and balance the body on only two legs.

14. Interesting Facts… • The human hand has 27 bones; your face has 14! • The longest bone in your body? Your thigh bone, the femur -- it's about 1/4 of your height. The smallest is the stirrup bone in the ear which can measure 1/10 of an inch. • Did you know that humans and giraffes have the same number of bones in their necks? Giraffe neck vertebrae are just much, much longer! • You have over 230 moveable and semi-moveable joints in your body.

15. What is a bone made of? • A typical bone has an outer layer of hard or compact bone, which is very strong, dense and tough. • Inside this is a layer of spongy bone, which is like honeycomb, lighter and slightly flexible. • In the middle of some bones is jelly-like bone marrow, where new cells are constantly being produced for the blood.

16. What's bone marrow? • Many bones are hollow. Their hollowness makes bones strong and light. • It's in the center of many bones that bone marrow makes new red and white blood cells. • Red blood cells ensure that oxygen is distributed to all parts of your body and white blood cells ensure you are able to fight germs and disease.

20. Bone is one of the strongest materials. Bones are much lighter than steel or concrete, but weight for weight, they are much stronger.

21. Are your bones alive? • Bones not only are made of a mix of hard stuff that gives them strength, but also tons of living cells which help them grow and repair themselves. • The bone cells rely on blood to keep them alive. Blood brings them food and oxygen and takes away waste.

22. If they weren't made of living cells, broken bones would never mend. • Your bone cells are busy growing and multiplying to repair the break! • When you break a bone, blood clots form to close up the space between the broken segments. Then your body signals bone cells to deposit more of the hard stuff to repair the break.

23. They actually range in color from beige to light-brown. The white, sterile bones seen in museums have been boiled and cleaned.

24. Click on the link below to watch a short video clip on the skeletal system: http://www.kidshealth.org/PageManager.jsp?lic=1&article_set=59294&cat_id=20607