The SkeletalMuscular System Meet Charlie Why do we

The Skeletal/Muscular System

Meet Charlie • Why do we need a skeleton? • Broken bones, x-ray • Find the bone on Charlie • http: //www. innerbody. co m/image/skelfov. html

Skull Shoulder Blade Humerus Ulna Radius Collarbone Ribs Vertebrae Pelvis Femur Tibia Fibula

Skull Shoulder Blade Humerus Ulna Radius Collarbone Ribs Vertebrae Pelvis Femur Tibia Fibula

Why do we need a skeleton? N Protection N Movement N Support

Movement and joints

Joints • occur where bone meets bone • 2 main divisions of joints: Ø Immovable Ø Moveable

Immovable fused joint • No movement • Where? – skull, pelvis

Moveable E. g. synovial joint

E. g. hinge joint • Movement in one direction only • Where? - Elbow and knee

E. g. ball and socket joint • Movement in all directions • Where? – shoulder and hip

Double jointed? • having unusually flexible joints especially of the limbs or fingers • Joint hypermobility

Summary There are 3 main types of joints: 1. Fused joint e. g. skull 2. Ball and socket joint e. g. shoulder and hip 3. Hinge joint e. g. elbow and knee

Muscles and joints

What holds our bones together? • Ligaments connect bone to bone • Tough rope like fibres known as ligaments. • Restrict movement

Can bones move on their own? 2 1

What joins muscles to bones? • Tendons join muscle to bones • Strong and nonelastic • Pulls on bone

How do muscles work? • Muscles can only actively contract – Relaxing does not require action • Muscles work in pairs – Called Antagonistic pairs • When one muscles contracts, the other relaxes • E. g. biceps and triceps

The biceps and triceps - an antagonistic pair

Tendon Biceps Contracted Tendon Triceps Relaxed

Tendon Triceps Biceps Contracted Relaxed Tendon

Tendon Biceps Contracted Tendon Triceps Relaxed

Tendon Triceps Biceps Contracted Relaxed Tendon

Bone composition • Bone is made of living and nonliving material • The living material lays down the non -living

What is bone made of? Organic – living – cells and protein • Cells – take up calcium salt from the blood – Cells release salts to make hard material • Protein – Flexibility • Inorganic –non-living – Calcium salts

How do we keep our bones healthy? • Weight bearing exercise • Calcium • Vitamin D

Summary • • Ligaments connect bone to bone Tendons join muscle to bones Muscles can only actively contract Muscles work in pairs called Antagonistic pairs • Bone is made of living and non-living material • Healthy bones need exercise, calcium and vitamin D.