NCERT Summary: Body Movements | Science Class 6 PDF Download

What is Locomotion?

• Locomotion is movement of the entire body from one place to another.
• Locomotion forms a framework that gives shape and support to the body.
• The human body consists of 206 bones.
• Bones protect internal organs.

Parts of Human Skeleton

• The bones present in our body form a framework this frame work is called Skeleton.
• The human skeleton has two parts:
  (i) The axial skeleton system: It includes the skull, vertebral column and the chest bones or the rib-cage.
  (ii) Appendicular skeleton system: It includes hip girdles and shoulder and the limbs.

Types of joints in Human Body

Different types of Joints

• Ball and socket joints
• Pivotal joints
• Hinge joints
• Fixed joints

1. Ball and socket joints

• It is a type of joint in which ball shape surface of one bone fitted into the hollow space of another bone known as socket.

2. Pivotal Joints

• Pivotal joints allow for flexibility, extension, rotation and twisting.

3. Hinge Joint

• It is found between two or more than two bones where we need back and forth movement.

4. Fixed Joint

• It does not move in any direction.

Bones

• Skeletal structure is composed of hard material which is made up of calcium called bone Various shape and functions of bones
• The number of small bones on the back side these small bones combine called as backbone, which is helpful in bending front and back.
• Bones which joins the chest and the backbone is called ribs
• If you will touch just below your stomach area you will find the presence of pelvic bone.
• The skull is the most hard and tough bone of our body which protects our brain from any mechanical injuries.

Cartilage

• It is softer and more flexible than bone. Cartilage is found between the joints of knee and hips.

Muscles

• Muscles are attached to the bones and it is responsible for the movement of human body.
• There is change in the length of muscle due to contraction and relaxation.

Gait(Locomotion) of Animals

Locomotion of Earthworm

• Earth worms commonly found in soil, it do not have bones. Their body is segmented, forms rings all over.

Locomotion of Snail

• Snails commonly found on land or in soil.
• It possesses wavy movement with muscular contraction.
• Snail has hard shell on its back but it is not made up of bone and not helpful in locomotion.

Locomotion of Cockroach:

• Cockroach is an insect and is a terrestrial animal mostly a common household pet.
• The body is divided into three parts—head, thorax, and abdomen.
• 3 pair of legs is present in thoracic part which moves by the muscles present near its limbs (legs).
• The body is covered with the outer hard exoskeleton.
• It uses breast muscles for the movement of wings due to which they can fly.

Birds

• Birds were egg laying animal with feathers, wings and beak.
• Fore limbs of birds were modified into wings due to which these can fly.
• Hind limbs are legs due to which they can jump, walk or swim as can be seen in ducks.
• The skeleton of birds is hollow to reduce weight and the breastbone muscle use to move the wings up and down.

Fishes

• Fishes found in oceans, rivers, lakes, aquarium etc.
• Fishes has well-arranged skeleton covered with strong muscles.
• This movement is helped by the fins present on tail and also the fins presents on body helps to balance the body while swimming.

Snakes

• Snakes live on ground, water, on trees. These were legless reptile.
• During its movement snakes creates curves in many loops which pushes them to the forward direction, they moves very fast but not in straight-line the motion created by snakes is called serpentine motion.