Why do you think that teens might not always practice these healthful behaviors?

1. Quick Quiz Complete each of these statements with always, sometimes, or never. I ____ warm up before exercising. When I ride a bicycle or play contact sports, I ____ wear a helmet and other protective gear. When I ride in a vehicle, I ____ fasten my seat belt. My backpack for school is ____ less that 15% of my body weight. I ____ make an effort to eat balance meals and exercise regularly. Why do you think that teens might not always practice these healthful behaviors?

2. Section 11.1 Your Skeletal System Goals/Objectives Identify the five main roles of the skeletal system. Describe the functions of bones and joints. Explain how you can keep your skeletal system healthy.

3. Key Terms Skeletal system The body system that serves as a support framework, protects vital organs, works with muscles to produce movement, and produces blood cells.

4. Functions of the Skeletal System Your skeletal system has five main roles. • provides support • protects internal organs • allows your body to move • stores and produces materials that your body needs (blood cells)

5. Support and Protection • Your skeleton is made up of all the bones inyour body. • Your skeleton gives your body its basic shape and provides the support that you need. • Many bones of the skeletal system protect internal organs.

6. Movement In coordination with your muscular and nervous systems, your skeletal system allows you to move.

7. Storage and Production of Materials • Your bones store essential substances which are released when other parts of the body need them. • Some bones also produce blood cells.

8. Skull The Skeletal System 9 1) Sternum (breastbone) 10 1 2) Vertebral column (backbone) 11 12 12) Ribs 3) Carpals 2 13 13) Radius 4) Metacarpals 14 15 14) Ulna 5) Phalanges 3 4 15) Pelvic girdle 6) Tarsals 5 16 16) Femur 7) Metatarsals 17 17) Patella 8) Phalanges 18 19 18) Fibula 9) Clavicle (collarbone) 10) Scapula (shoulder blade) 19) Tibia 6 7 11) Humerus 8

9. Skull The Skeletal System 9 1) __________________ 10 1 2) _____________________ 11 12 12) ______ 3) ____________ 2 13 13) ________ 4) ____________ 14 15 14) ______ 5) ____________ 3 4 15) __________ 6) ____________ 5 16 16) ________ 7) ____________ 17 17) ________ 8) ____________ 18 19 18) ________ 9) ____________ 10) __________________ 19) _______ 6 7 11) ____________ 8

10. 17 18 11 19 20 12 Radius 21 22 Carpals 13 14 23 24 Fibula 25 15 16 Phalanges

11. Bones and Joints • Your skeletal system is made up of just over 200 bones. • A place in your body where two or more of your bones come together is called a joint.

12. Development of Bones • Your bones are living structures that undergo change throughout your life. • Cartilage is a tough supportive tissue that is softer and more flexible than bone. • By young adulthood, most of this cartilage is replaced by bone in a process called ossification. • In a process called ossification minerals, such as calcium and phosphorus, are deposited within the cartilage, making it hard.

13. Structure of Bones • Bone consists of two different types of tissue—compact bone and spongy bone. • Another type of tissue called marrow fills the spaces in bones. • There are two types of marrow—red and yellow.

14. Compact Bone Compact bone makes up theouter layer of all bones. Althoughit looks dense and solid, It is fullof holes for nerves and blood vessels. Spongy Bone Spongy bone contains flatand needlelike structuresthat resist stress. Red bonemarrow may fill the openspaces in some bones. Outer Membrane An outer membranecovers most of a long bone.The inner portion of a membrane contains cells that build up and breakdown bone. Central Cavity Central cavities in long bones usually contain yellow bone marrow (fat).

15. Joints • Joints allow for movement and protect bones from friction and force. • Bones are held together at joints by strong, fibrous bands called ligaments.

16. Pivot Joint A pivot joint connects your head to the first vertebra in your backbone. It allows you to turn your head from side to side. Ball-and-Socket Joint A ball-and-socket joint allows movement in all directions. Your shoulders and hips are ball-and-socket joints. Gliding Joint Gliding joints allowmovement in many directions as the bones slide along each other. Your wrists and ankles contain gliding joints. Hinge Joint Hinge joints allow bending and straightening movements.Your knees and elbows are hinge joints.

17. 1)_______ Joint connects your head to the first vertebra in your backbone. It allows you to turn your head from side to side. 3)_____________ Joint allows movement in all directions. Your shoulders and hips are these joints. 2)_______ Joint allow movement in many directions as the bones slide along each other. Your wrists and ankles contain these joints. 4)_______ Joint allow bending and straightening movements. Your knees and elbows are these joints.

18. FYI – Cracking Knuckles • Cracking knuckles has not been clearly linked to causing arthritic problems. • The popping or cracking sound is normal. • When a joint is pulled, lower pressure is created in the joint area, causing tiny air bubbles to break. • Which is the noise people hear.

19. Keeping Healthy • A combination of eating well, exercising, and avoiding injuries contributes to lifelong bone andjoint health. • Regular medical checkups can help detect skeletal system problems.

20. Eating Well • Adequate intake of calcium and phosphorus will help your bones grow to their maximum size and strength. • Osteoporosis is a condition in which the bones become weak and break easily. • Other nutrients that are important for bone health include potassium, magnesium, and vitamins A, C, and D.

21. Exercising • Another way to build strong bones and prevent osteoporosis is to get plenty of weight-bearing exercise. • Activities in which the bones support the entire weight of your body help your bones grow strong and dense.

22. Avoiding Bone Injuries • A fracture is a break in a bone. • You can protect your bones from fractures. • When participating in a physical activity, wear appropriate safety equipment, such as helmets and pads. • Always wear a seat belt when traveling in a vehicle.

23. Avoiding Joint Injuries Proper warm-up and stretching exercises are important to help prevent joint injuries. • Sprains - A sprain is an overstretched or torn ligament. • Dislocations - In a dislocation, the ends of the bones in a joint are forced out of their normal positions. • Torn Cartilage - Serious damage to the cartilage between the bones in a joint is known as torn cartilage. • Overuse Injuries - When an activity is performed too often or too strenuously, joints may become irritated and inflamed.

24. Medical Checkups • A doctor can advise you on how to prevent serious injury or recommend other professionals who can help you. • A nurse or doctor may check your spine for scoliosis, an abnormal curvature of the spine.

25. Questions • List the 4 main functions of the skeletal system. • Explain the function of bones. • Describe the two types of bone marrow. • What is a joint? Describe the function of movable joints in the body. • Identify 4 ways you can help your skeletal system stay healthy. • What type of joint allows you to kneel down? • What type of joint allows you to move your arm in a circle? • If you run your fingers down the center of your back, which bones can you feel? • What joint allows you to wave hello to a friend? What type of joint is it? • What connects bones?