NCERT Solutions Class 6th Science Chapter – 5 Body Movements Notes In this Chapter We Will read about Skeletal System, Functions of skeleton, X-ray machine, The skull, Eye sockets, Gait of animals, Snakes, Insects and Snails etc. and More much. you have provided easy notes which use in your study make progress in education.
NCERT Solutions Class 6th Science Chapter – 5 Body Movements
Chapter – 5
Body Movements
Notes
Skeletal System
• Bones in our body form the framework that supports the whole body. This framework is called the skeleton. • Our skeleton is made up of a number of bones and cartilages. • There are about 650 muscles attached to the various bones in our body. • The bones are hard and rigid. • Cartilages are comparatively soft and elastic.
Functions of skeleton • The Skeleton system gives support to the body. • It protects the inner organs. • Together with muscles, it gives the body its shape. • Red blood cells and some white blood cells are produced in the marrow of the bone.
X-ray machine
• We can get photographs of bones by a machine called an X-ray machine. • Doctors use these photographs to examine the injuries and diseases of bones. • The bones in our body vary in size and shape. Different types of c bones have different functions.
Bones of hands and legs – Bones of arms, thighs, etc., are long. They give strength to our bodies. The bones of fingers and toes are short. They help us in holding things. The hands and legs are constructed in the same pattern as described below: (See Figs).
Part of hand
Part of leg
Number of Bones
Upper arm
Thigh
One long bone
Forearm
Lower leg
Two long bones
Wrist
Ankle
Several small bones
Palm
Foot
Five bones
Fingers
Toe
Each has three small bones (except the thumb, which has two small leaves)
The skull – The skull has two main parts
Cranium – The bones of the cranium are flat. They are held firmly like a zipper. It covers and protects the brain.
The Shoulder bones – The shoulder bone is formed by the collar bone and the shoulder blade. The shoulder bones are flat and large. They help in forming joints with long bones.
Facial bones – The facial bones comprise the upper jaw, lower jaw and a few other bones. The lower jaw is movable. The movement of the lower jaw enables us to eat, talk and sing.
Eye sockets – The skull also includes a pair of eye sockets. These form a safe pocket for the eyes.
The backbone – The backbone or vertebral column is composed of 33 small, ring-like vertebrae joined end to end. It forms a hollow bony tube. The main nerve cord passes through it.
The Chest bones – 12 pairs of ribs along with the backbone make a cone-shaped cage, called rib-cage, which protects the heart.
Hip bones – The hip bone is formed by the fusion of three bones. Like shoulder bones, the hip bones are also flat and large. They help in forming joints with long bones. Together with the last two parts of the backbone, it forms a large bony bowl called the pelvis.
Bone joints
• The place where two or more bones meet together is called a joint. In our body, five types of joints are present namely. • Fixed joints that do not allow movement, e.g., joints of the cranium. • Ball and socket joints allow movement in all directions, e.g., joints between the upper arm and shoulder, thigh and hip. • The pivotal joint allows movement in many planes, e.g., the skull makes such a joint with the first two vertebrae. • Hinge joints allow movement only in one direction, e.g., fingers, the knee, etc. • Gliding joints allow only a limited amount of movement, e.g., joints of the backbone.
Muscles – The bones are moved by the alternate contractions and relaxations of two sets of muscles.
Tendons – join muscles to the bones.
Ligament – joins two bones.
Bristles – Bristles are hair-like structures, connected with muscles. The bristles help to get a good grip on the ground.
Cavity – It is the hollow space or cavity in one bone, into which the other bone fits. Such joint allows movements in all directions.
Gait of animals – Some animals do not have bones. They have muscles that help to extend and shorten the body. During movement, the animal first extends the front part of the body, keeping the rear position fixed to the ground. After that animal fixes the front end and releases the rear end. Now animal shortens the body and pulls the rear end forward. During this practice, the animal moves forward by a small distance.
Rib cage – Ribs join with the chest bone and the backbone together to form a box. This is called a rib cage.
There are two kinds of movements:
• The organisms move their body parts without changing their position. • Animals move from one place to another. This kind of movement is called locomotion.
Birds – Most birds have two kinds of locomotion. They walk with their legs on the ground. They also fly in the air. Ducks and swans also swim in the water.
Flying adaptations – Streamlined body, bones with air spaces, forelimbs modified into wings, air sacs connected to lungs and massive flight muscles are some adaptations in birds for flying.
Fish – The fish swims by forming loops alternately on the two sides of the body. The tail pushes them forward. The vertebrae and the muscles attached to the work for it.
Snakes – Similarly, the snakes crawl on the ground by alternately looping sideways. A large number of vertebrae and associated muscles push the body forward. The ventral scales also help in the process.
Insects – The body and legs of insects have hard joined coverings, forming an exoskeleton. The muscles of the breast connected with three pairs of legs and two pairs of wings help the cockroach to walk and fly.
Snails – The snails are moved by the muscular foot. The hard unjoined shell has no relation to the foot.
Earthworm – The earthworm moves by alternate extension and contraction of the body affected by the muscles. The minute movable bristles help in gripping the ground.
Backbone – The backbone or vertebral column is composed of 33 small ring-like bones called vertebrae. It is a hollow bony tube.
Ball and socket joint – A joint in which the rounded end of one bone fits into the cavity of the other bones.
Bristles – Hair-like structures projecting out of the body of earthworms. With the help of these, it fixes itself with the ground.
Cartilage – It is the additional part of the skeleton that is not as hard as the bones and which can be bent also.
Cavity – The bowl-like part (hollow space) in the shoulder bone allows the rounded end of the arm bone to fit into it to form a ball and socket joint.
Fixed joints – Some of the joints allow no movement. These are called fixed joints, e.g., joints in the skull and upper jaw.
Gait of animals – Some animals do not have bones. They have muscles that help to extend and shorten the body. During movement, the animal first extends the front part of the body, keeping the rear position fixed to the ground. After that animal fixes the front end and releases the rear end. Now animal shortens the body and pulls the rear end forward. During this practice, animal moves forward by a small distance.
Hinge joint – Hinge joint is found in the fingers, elbow and knee. It allows movement only in one direction.
Muscle – Muscles are involved in the movement of bones.
Outer Skeleton – Skeleton found outside the body is called an outer skeleton, e.g., hair and nails in humans.
Pelvic bones – Bones in the hip region are called pelvic bones.
Pivotal joint – The joint where our neck joins the head is a pivotal joint.
Rib cage – Ribs join the chest bone and the backbone together to form a box. This is called a rib cage.
Shoulder bones – The two bones of the shoulders are called shoulder bones.
Skeleton – The framework of the body which is made up of bones and cartilage is called the skeleton.
Streamlined – The body shape where the body tapers at both ends is called the streamlined body, e.g., the body of birds and fish.
Q. 1. What do you mean by movement?
Ans – The changing position of the body or any part of the body is called movement.
Q. 2. At which part does the arm rotate?
Ans – The arm rotates on the round pit-like structure.
Q. 3. If you tie a scale with your arm, are you able to bend your elbow?
Ans – No, we cannot bend our elbow.
Q. 4. Name the places where two parts of the body are seen to be joined together.
Ans – These places are called joint.
Q. 5. If there are no joints then will it be possible to move?
Ans – No, it is not possible.
Q. 4. Name the places where two parts of the body are seen to be joined together.
Ans – No, bones cannot be bent.
Q. 7. Can we bend our body at every part?
Ans – No, we can bend our body only at joints.
Q. 8. How many types of joints are there?
Ans – There are five types of joints in our body.
Q. 9. What is cavity in bone?
Ans – The hollow space in the bone is called cavity.
Q. 10. Give an example of pivotal joint.
Ans – The joint of skull with backbone.
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