THE SKELETAL SYSTEM

What the Skeletal System Does... 5 major functions: Shape and support Movement Protects your organs Produces blood cells Stores minerals

Shape and Support Backbone (or vertebral column) is the center of the skeleton. Vertebrae: The small bones that make up the backbone.

Movement Bones are associated with muscles. Muscles pull on the bones to make the body move.

Protection Bones protect your organs. Skull protects brain. Breastbone and ribs protect heart and lungs.

Blood Production Bones are like factories that produce blood cells.

Mineral Storage Bones store calcium and phosphorous. Bones release minerals into the blood when the body needs them.

Joints of the Skeleton Joint: A place in the body where 2 bones come together. Joints allow bones to move in different ways. 2 types of joints: immovable and moveable

Immovable Joints Joints that connect bones in a way that allows little or no movement. Bones of the skull are held together by immovable joints.

Moveable Joints Allow body to make movements. Ligaments: Strong connective tissues that hold moveable joints together. Cartilage: A 2nd type of connective tissue.

4 Types of Moveable Joints Hinge joint Ball and socket joint Pivot joint Gliding joint

Hinge Joint A hinge joint allows forward or backward motion. Your knee is a hinge joint that allows you to bend and straighten your leg. Your elbow is also a hinge joint.

Ball and Socket Joint Ball and socket joints allow the greatest range of motion. The ball and socket joint in your shoulder allows you to swing your arm freely in a circle. Your hips also have ball and socket joints.

Pivot Joint A pivot joint allows one bone to rotate around another. The pivot joint in your neck allows you to turn your head from side to side.

Gliding Joint A gliding joint allows one bone to slide over another. The gliding joint in your wrist or ankle enables you to bend and flex as well as make limited side to side motions.

Cartilage Covers the ends of bones and keeps them from rubbing.

Bone Structure Bones are complex living structures that undergo growth and development.

Compact bone- Hard and dense, but not solid. Spongy bone- Like a sponge with many small spaces within it. Marrow- Soft connective tissue that fills the spaces in your bones. (2 types- red and yellow)

TYPES OF BONE MARROW Red Marrow- Produces most of the body’s blood cells. As a child, most of your bones contain red marrow. Yellow Marrow- Stores fat. As a adult, most of your bones contain 50 %yellow marrow and 50 % red marrow.

Bone Strength The structure of bones make them both strong and lightweight. Bones can absorb more force than concrete or granite rock. 20 percent of an adults body weight is bone.

Bone Growth Bones are alive! They contain cells and tissues, such as blood and nerves.

Bone Development As an infant, much of your skeleton is cartilage. Over time, most of your cartilage is replaced with hard bone tissue.

Taking Care of Your Bones A combination of a balanced diet and regular exercise are important for a lifetime of healthy bones.

How Does Physical Activity Help Build Healthy Bones? Bones are living tissue. Weight-bearing physical activity causes new bone tissue to form, and this makes bones stronger. This kind of physical activity also makes muscles stronger. Bones and muscles both become stronger when muscles push and tug against bones during physical activity.

Exercise Examples Weight-bearing physical activity keeps you on your feet so that your legs carry your body weight. Some examples of weight-bearing physical activities include: Walking, jogging, or running Playing tennis or racquetball Playing field hockey Climbing stairs Jumping rope and other types of jumping Playing basketball Dancing Hiking Playing soccer Lifting weights

Osteoporosis A condition in which the body’s bones become weak and break easily (not enough calcium).