The skeletal system consists of bones, cartilage, and connective tissue that hold bones together. Bones have two types of tissue - compact bone that is solid and spongy bone that has many open spaces. Bones perform four key functions: providing structure, allowing movement, protecting organs, and storing minerals. There are three types of joints - fixed, slightly movable, and freely movable. Common injuries to the skeletal system include fractures and broken bones, while diseases include arthritis which causes joint swelling and stiffness and osteoporosis which reduces bone density.

1. Life Science : 1.2 The Skeletal System

2. Objectives: Identify the major organs of the skeletal system. Describe four functions of bones. Describe three types of joints. List three injuries and two diseases that affect bones and joints.

3. Bones Bones, cartilage, and the connective tissue that holds bones together make up your skeletal system. Bone Structure Bone tissue without any visible open spaces is called compact bone. Bone tissue that has many open spaces is called spongy bone. Bones contain a soft tissue called marrow. Bone Growth Most bones start out as a flexible tissue calledcartilage. Eventually, most cartilage is replaced by bone.

4. 4 functions of Bones

5. Joints Joint Place where two or more bones meet. Joints are held together byligaments. Three Joints:

6. Skeletal System Injuries and Diseases Bones may be fractured or broken. Ligaments can be stretched or torn. Arthritis is a disease that causes the joints to swell or stiffen. Osteoporosis is a disease that causes bones to become less dense.