Cavity: The rounded end of one bone fits into the cavity of the other bone.
Pivotal Joint: The joint where our neck joins the head is a pivotal joint. It allows us to bend our head and other movements.
Hinge joints: This elbow has a hinge joint that allows only a back and forth movement.
Fixed joints: Some joints between bones in our head cannot move. These joints are called fixed joints.
Carples: It is made up of several small bones called carples. Like Palm and fingers.
Ribcage: The ribs are bend which 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 chest.
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.
Shoulder bones: The two bones on the back are prominent where the shoulders are. They are called shoulder bones.
Pelvic bones: They enclose the portion of your body below the stomach. This is the part we sit on.
Cartilage: Some additional parts of the skeleton that are not as hard as the bones and which can be bent. These are called cartilage. In the upper parts of the ear that is not as soft as the ear lobe but, not as hard as a bone. This is cartilage. It is also found in the joints of the body.
Muscle: It is a swollen region in the upper arm. It bulged due to contraction.
The body of an earthworm is made up of many rings joined end to end. It does not have bones. It has muscles which help to extend and shorten the body. During movement, the earthworm first extends the front part of the body, keeping the rear portion fixed to the ground. Then it fixes the front end and then shorten the body and pulls the rear end forward. Under its body, it has a large number of tiny bristles projecting out. The bristles are connected with muscles. The bristles help to get a good grip on the ground. It eats the soil. Its body then throws away the undigested part, which is more useful for plants.
The body of a fish tapers at both ends. This body shape is called streamlined. During swimming, muscles make the front part of the body curve to one side and the tail part swings towards the opposite side. This makes a jerk and pushed the body forward. This is helped by the fins of the tail. Other fins on the body of fish help to keep the balance of the body and to keep direction.
Snakes have a long backbone and 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.
The snake’s body curves into many loops. Since its long body makes many loops and each loop gives it this push, the snake moves forward very fast and not in a straight line.
The ancient Greek philosopher Aristotle, in his book ‘Gait of Animals’, asked himself many questions related to the body structure of Animals and some also of humans.