The Motor System

C.E.I.P. Manuel Laza Palacio Carmen Posadas Gallardo Manuel Alvarez Vigil

Movement

• Our muscles ,bones and joints work together so that we can move.

• The skeleton can not move on its own. It needs muscles.

• Muscles can contract and relax and this is the way people and lots of animals can move:

It is very important to do exercise every day so that our muscles get

strong and resistant.

The Motor System and The Muscular System:

• We use the motor system to move our body.The motor system has muscles, bones and joints.

• There are lots of muscles in every part of our body, and together they form the muscular system.

• Muscles are elastic. They contract and relax,and they are attached to bones.

The muscles in our body:

• In our head we have jaw muscles, they open and close our mouth, and face muscles, that we use when we make expressions on our face.

• In the trunk we have lots of muscles: neck muscles, pectorals, intercostals and abdominals are the main ones.

• In our arms we have the deltoids in our shoulders,and the biceps and triceps that we use to bend and stretch our arms.

• In our legs, we have quadriceps and biceps and we use them to bend our legs. We also have calf muscles at the back of our legs.

The Bones: The Skeleton

• All of the bones in the body form the skeleton.Bones are hard,and they can have different shapes. The bones in the arms and legs are long bones. The vertebraes are short bones and the bones in the skull are flat bones.

What are the uses of the skeleton?

• It holds up the body and keep it firm.The skeleton is like a frame and it gives the body a shape.

• It protects the organs inside our body. For example, the ribs protects the heart and the lungs, and the skull protects our brain.

Main bones in the body:

• In the head we have the skull. It protects the brain, and give the face its shape.

• The rib cage is inside the trunk. The bones that form the rib cage are: the spine, that is made of small bones called vertebrae,and the ribs that join the spine to the sternum. That is a strong bone in the centre of our chest and it is a flat bone.

• In the arms we have the humerus, ulna and radius.

• In the legs we have femur, tibia and fibula.

Joints:

• The place where two or more bones meet is called a joint.

• There are two types of joints:1. Mobile joints: to bend and stretch

different parts of our body:the neck, shoulders, elbows, wrists, hips, knees and ankles are the mobile joints.

2. Fixed joints do not move, like the skull, for example.