MODELING JOINTS, MUSCLES AND BONES MOVING BODIES

VOCABULARY Joint: The place where two or more bones meet Cartilage: A smooth, flexible material that lines and cushions joints. It is also the material that nose and ears are made of Ligament: Strong bands of tissues that hold bones in place at joints Tendon: Less flexible tissues that connect muscles to bone

More vocabulary Muscle: An organ that can relax, contract and provide the force to move body parts. Extensor muscle: pulls bones apart at joints Flexor muscle: pulls bones together at joints

Ball and Socket Joint This joint consists of a bone with a rounded end that fits into a cuplike cavity on another bone. This type of joint is found in hips and shoulders. It provides for a wide range of motion which is why arms and legs can swing in almost any direction.

Hinge Joint This joint has a back and forth motion like hinges on a door Elbows, knees and fingers have hinge joints. These have a smaller range of motion than ball and socket joints.

Gliding Joint One part of a bone slides over another bone. These joints move in a back and forth motion and are found in wrists, ankles and between vertebrae. These are used the most in the body.

Pivot Joint In these joints, one bone rotates in a ring of another bone that does not move. Turning the head is an example.

How muscles move bones Muscles can only contract or get shorter Therefore, muscles work in pairs called flexors and extensors. A flexor muscle pulls the bones of a joint together An extensor pulls these same bones apart. In a joint, there are opposing muscles that contract in opposing directions so you can move in a range of motion. For example, your biceps (flexor) bend your arm at the elbow and your triceps (extensor) straighten your arm. One group of muscles contracts while the opposing muscle group relaxes.

Link to an interactive example. http://www.purchon.com/biology/flash/elbow.swf

Muscles of the Body

How we move: The Big Picture The food we eat and air we breath provides the energy for our muscles to contract. The circulatory system transports these needed materials to all body tissues Muscles, which are connected to bones with tendons, work in pairs to move our bones at joints. Bones are connected at joints by ligaments which hold the bones together. Nerve impulses given by the brain determine our movements

Instructions for Modeling Movable Joints or How Muscles Work Draw designs. Include measurements and materials used for bone, ligaments, tendons and muscles. Build the model with classroom materials Test the model. Research and modify if needed Test the model with another group, modify based on feedback Present to class with explanations of how your model is a good representation of how the body moves. Describe revisions. How could the model be improved? Include: type of joint, where the joint is found, type of movement, muscles involved, materials used for bones and ligaments or tendons, muscles and bones.