CBSE Class 6 Science Chapter 8 Notes Body Movements
Body Movements Class 6 Notes Understanding the Lesson
1. Bones and cartilages form the skeleton of our body. It gives the outer shape to our body and helps in movement. It also protects the inner organs.
2. Human beings and other animals show two types of body movements.
3. The movements of the body parts (g., mouth, head, backbone, etc.)
4. The movement of the whole body from one place to another (locomotion).
5. In human beings, the skeleton is inside the body, so it is called ‘endoskeleton’.
6. The X-ray images show the shape and number of bones in the various parts of our body.
7. There are 206 bones in human skeleton.
8. Cartilage is a firm but flexible material found at some places in the skeleton.
9. The place where two or more bones meet the skeleton is called a joint.
10. In the freely movable joints like elbow, shoulder, knee and hip joints, the ends of the bones joining the joint are held in place by a strong connective tissue which is called ‘ligament’.
11. The main types of joints in the human body are:
- Hinge joint
- Ball and socket joint
- Pivot joint
- Fixed joint
12. A hinge joint is a joint which allows movement in only one direction, e., forward -and backward, e.g., knee and elbow joints.
13. In the ball and socket joint, one end of the bone has a round shape like a ball which fits into a socket (hollow space) of the other bone. Such a joint allows movement in all directions, g., shoulder joint.
14. In a pivot joint, a cylindrical bone twines in a ring.
15. In some joints, the bones are held so tightly together that they cannot move at all. Such joints are called fixed joints.
16. Muscles are attached to the bones of our skeleton through strong fibres called
17. The bones are moved by alternate contractions and relaxations of two sets of muscles.
18. The human skeleton consists of skull, backbone, ribs, breastbones, shoulder bones, hip bones, arm bones and leg bones.
19. Ribs are attached to the upper part of the backbone forming a rib cage. There is a breastbone called sternum in front of rib cage.
20. The shoulder bone consists of two bones – the collar bone and the shoulder blade.
21. The scientific name of collar bone is clavicle and that of shoulder bone is
22. The upper arm consists of a single bone called humerus.
23. The lower arm is from the elbow to the wrist. The lower arm is made up of two bones radius and
24. The upper leg consists of a single bone called
25. The lower leg consists of two bones tibia and fibula
26. There is a knee cap on the knee which is called
27. The bony part of our head is called The skull is made of 22 bony plates joined together.
28. The brain is made up of soft tissues which could be easily damaged without a hard covering.
29. The eyes are contained in two large cavities called ‘eye socket’ in front of the skull.
30. The scientific name of backbone is vertebral column.
31. The small bones which make up the backbone are called vertebra.
32. The chest bones are called ribs. There are 12 pairs of ribs in the chest of our body.
33. Heart, lungs and the liver lie inside the bony ribcage.
34. The hip bone form a large, basin-shaped frame at the lower end of the backbone, to which the legs are attached.
35. The hips bone has two sockets one each on the two sides of its lower part.
36. Our hand is made up of three parts – the wrist, the palm and the fingers.
37. The wrist consists of 8 small bones known as
38. The palm of the hand is composed of 5 longer bones called
39. The fingers are made up of jointed bones called phalanges.
40. Cockroaches and birds are the animals which have legs to walk, on the ground and wings to fly in the air.
41. The body of a cockroach is covered with hard and tough outer covering called ‘exoskeleton’.
42. A cockroach has six legs (three legs on each side of its body).
43. A cockroach has two pairs of wings attached to its breast by flight muscles.
44. Birds walk on the ground and also fly in the air.
45. Birds can fly because of their strong muscles and light bones which work together.
46. The body of an earthworm is soft and segmented having no bone.
47. An earthworm moves by stretching out its body in the front, keeping the hind end fixed to the ground. Then it fixes the front end and releases the hind end. It then shortens the body and pulls the hind end forward.
48. The streamlined body shape of the fish enables it to move through water with least resistance.
Class 6 Science Chapter 8 Notes Important Terms
Ball and socket joint: A joint in which rounded end of one bone fits into the cavity of the other bone is called ball and socket joint.
Backbone: The backbone is a long hollow, rod-like structure running from the neck to the hips, inside our body. The scientific name of backbone is vertebral column.
Bristles: Hair like structures projecting out of the body of earthworms with which, it fixes itself with the ground.
Cartilage: It is the part of the skeleton that are not as hard as the bones but are tough and elastic.
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 ball and socket joint.
Fixed joints: Some of the joints allow no movement. These are called fixed joints, e.g., joints in skull and upper jaw.
Gait of animals: The patterns of movement of limbs in animals during their locomotion over a solid surface is called gait of animals.
Hinge joint: Hinge joint is found in fingers, elbow and knee. It allows movement only in one direction. Muscle: Muscle is a soft tissue which is involved in the movement of bones.
Outer skeleton: Skeleton found outside the body is called outer skeleton, e.g., hair and nails in human. 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 rib cage.
Shoulder bones: The two bones of the shoulders, i.e., clavicle and scapula, are called shoulder bones.
Skeleton: The framework of the body i.e., made up of bones and cartilage is called skeleton.
Streamlined: The body shape where body tapers at both ends is called streamlined body, e.g., body of birds and fishes.