1. The Skeletal System

2. Overview Allows Movement SupportProtection Red Blood Cell Production Mineral Storage

3. Overview A newborn baby has 305 bones in it’s body, and it continues to develop to the age of 25 At that age the bones fuse together to obtain maximum strength.

4. Overview The average adult skeleton has 206 bones The largest bones are in the thigh (Femur) and in the upper arm (Humerus). The smallest bones are the 3 tiny bones in you middle inner ear

5. Overview All bones are living organs, which contain living materials (cells), and non- living (mineral) materials

6. Divisions of the Skeleton The skeleton is divided into 2 parts: 1.The Axial Skeleton 2.The Appendicular Skeleton

7. Divisions of the Skeleton The Axial Skeleton refers to all bones that are grouped along the midline (middle) of the body. These include: the skull, spinal column & chest.

8. Divisions of the Skeleton The Appendicular Skeleton refers to appendages that are attached to the axial skeleton. These include: the pelvic girdle, arms & legs (126 bones)

9. Functions Body Movement Framework (support) Protection Mineral Storage Production of Red Blood Cells

10. Functions Movement: Bones work together with skeletal muscles to help produce movement Muscles, which are usually arranged in pairs, are attached to the skeleton, when one contracts…the other relaxes, etc…

11. Functions Muscles move the bones, bones meet (articulate) at the joints, and the whole body then becomes mobile

12. Functions Framework (Support): Bones provide support for tendons and ligaments and the framework for body shape Tendons= cords of thick, strong fibres that connect muscle to bone Ligaments= cords of thick, strong fibres that connect bone to bone

13. Functions Protection: Bones such as the cranium, ribs and sternum provide vital protection for internal organs such as the brain, heart and lungs

14. Functions Mineral Storage: Bones are a site for storage and the release of minerals. Foods that contain more calcium and phosphorus than the body are stored in the bones in the form of collagen. Collagen = A strong, flexible material produced by bone cells. Forms the main part of connective tissue such as tendons and ligaments

15. Mineral Storage

16. Functions Red Blood Cell Production: Bones are responsible for the production of new blood cells. The spaces between the spongy bone are filled with red bone marrow Haemoglobin is a protein inside RBCs that transports Oxygen around the body

17. Functions Red Bone Marrow is bone tissue that makes Red Blood Cells and some White Blood Cells Production decreases as you age, after peaking during puberty.

18. What’s in a Bone? Periosteum Is a tough membrane. Contains blood vessels that enter the bone at many points nourishing the cells inside. Contains the cells for growth and repair.

19. What’s in a Bone? Compact bone lies beneath the periosteum and as the name suggests it is hard and dense. Compact bone covers the spongy bone at either end of long bone.

20. What’s in a Bone? Compact bone is at it’s thickest at the shaft of the bone. Compact bone gives strength, whilst spongy bone acts as a shock absorber

21. What’s in a Bone? Yellow Bone Marrow fills the shaft of the long bone and is used as a fat storage site (long term energy). It is mostly made of fat cells