Body Movements
Joints :- we are able to bend or rotate our body in places where two parts of our body seem to be joined together — like the elbow, shoulder or neck. These places are called joints.
There are different types of joints in our body to help us carry out different movements and activities:-
1.Ball and Socket Joints:- Such a joint allows movements in all directions. It consists of a bone which has a round end which fits into the cavity (hollow space) of another bone. This helps the bone to rotate freely. For example – hip joints.
2. Pivotal Joints:- The joint where our neck joins the head is a pivotal joint .It allows us to bend our head forward and backward and turn the head to our right or left.
3. Hinge Joints:- Hinge joints allow only back and forth movement. For example:- Elbow.
4. Fixed Joints:- The bones cannot move at these joints. Such joints are called fixed joints. Joint between the upper jaw and the rest of the head which is a fixed joint.
Human Skeleton :- The human skeleton is composed of around 305 bones at birth. The number of bones in the skeleton changes with age. It decreases to 206 bones by adulthood after some bones have fused together.
All the bones in our body also form a framework to give a shape to our body.
Carpels :- The back of our palm is made up of several small bones called carpels.
Ribs:– Bones of the chest.
Rib Cage :- Ribs join the chest bone and the backbone together to form a box. This is called the rib cage. There are 12 ribs on each side of the chest. Some important internal parts of our body lie protected inside this cage.
Backbone :- It is made up of many small bones called vertebrae. The backbone consists of 33 vertebrae .The rib cage is joined to these bones.
Pelvic Bones :- They enclose the portion of our body below the stomach. This is the part
we sit on it.
Skull :- The skull is made up of many bones joined together. It encloses and protects a very important part of the body, the brain.
Cartilage :- some additional parts of the skeleton that are not as hard as the bones and which can be bent. These are called cartilage. For example:- Upper part of ear has cartilage.
Note:- Bones and cartilage form the skeleton of the human body. It gives the frame and shape to the body and helps in movement. It protects the inner organs.
Muscles:- Muscles work in pairs. A muscle can only pull. It cannot push.
Earthworms:-
- The body of an earthworm is made up of many rings joined end to end. An earthworm does not have bones. It has muscles which help to extend and shorten the body.
- Under its body, it has a large number of tiny bristles (hair like structures) projecting out. The bristles are connected with muscles. The bristles help to get a good grip on the ground.
Snail:-
- Shell is the outer skeleton of the snail, but is not made of bones. The shell is a single unit and does not help in moving from place to place.
- A thick structure and the head of the snail may come out of an opening in the shell. The thick structure is its foot, made of strong muscles.
Cockroach:-
- They have three pairs of legs. These help in walking.
- The body is covered with a hard outer skeleton. This outer skeleton is made of number of plates joined together and that permits movement.
Birds:- Strong muscles and light bones work together to help the birds fly. They fly by flapping their wings.
Fish:-
- The head and tail of the fish are smaller than the middle portion of the body – the body tapers at both ends. This body shape is called streamlined.
- Fish swim by forming loops alternately on two sides of the body.
Snake:-
- Snakes have a long backbone. They have many thin muscles. They are connected to each other even though they are far from one another. Muscles also interconnect the backbone, ribs and skin.
- Snakes slither on the ground by looping sideways. A large number of bones and associated muscles push the body forward.
International day of yoga :- 21 June