Tiêu đề 8 Body Movements.pdf ✅

Science Body movements Additional Important Questions Q1. Which is the longest bone in your body? Measure it with your scale. Ans. Femur is the longest bone in our body. It is a thigh bone. Q2. Does the shoulder bone also move when you move your arm? Ans. The shoulder bone does not move when we move our arm. Only arm moves, the shoulder bone remains fixed. Q3. Do the bones of the upper jaw move? Ans. The bones of the upper jaw are joined with fixed joints. So they do not move. Q4. Name various parts of skeletal system. Ans. The skeletal system can be divided into following main parts: 1. Skull 2. Back bone 3. Limb bones 4. Chest bones 5. Shoulder bones 6. Hip bones. Q5. What is cartilage? Give one example. Ans. These are some additional parts of the skeleton that are not as hard as the bones and which can be bent. For example, the upper part of our ear has cartilage. Q6. At which point does the arm rotate? Ans. The arm rotates on the round pit like structure. Q7. Name the bones which protect the heart from all sides.
Ans. Breastbone from front and the backbone at the back makes a type of box to protect the heart. Q8. Keeping your arm straight, move it forwards and backwards, up and down. Can the arm move freely in all directions? Ans. Yes, the arm can move forward, backward down and up. Q9. Why do animals move from one place to other? Ans. Animals move from one place to other: (i) To obtain their food and shelter. (ii) To protect themselves from enemies and unfavourable climate. Q10. Name the organs of locomotion of (a) Man (b) Birds (c) Fish Ans. (a) Man – Legs (b) Birds – Wings (c) Fish – Fins. Q11. Do the bones on top of the skull move? Ans. The bones on top of the skull form the structure similar to the structure of teeth. They are joined strongly with one another. So these bones are also fixed. These bones do not move. Q12. What is the function of skeleton? Ans. Skeleton: (a) It forms the framework of body. (b) It gives shape and structure to the body. (c) It protects the internal organs. (d) It helps in the movement and keeping body erect. (e) Ribs of chest help in breathing Q13. What is exoskeleton? Explain giving examples. Ans. The bodies of crabs, insects and spiders are covered and protected by hard coverings. These hard parts outside are called exoskeleton (ekso–skel–e–ton). Nails and hair are also exoskeleton found in our body. Similarly the scales of cockroach, fish, outer shell of snails and oyster are also exoskeleton of these animals.
Q14. What is a bone joint? Describe various kinds of joints found in our body. Ans. Joints: The place where two or more bones meet together is called a joint. There are five main types of joints in our body. (i) Fixed joints: Some attachments do not allow movement. They are fixed joints. Joint of the cranium is a fixed joint (ii) Ball and socket joints. The rounded end of one bone fits into the hollow space of the other bone. Such a kind of joint allows movements in all directions and is called ball and socket joint. For example: the joint between the upper arm and the shoulder; the thigh and the hip. (iii) Pivotal joints: The skull is joined to the first two vertebrae of the backbone like a ball to a stick. This type of joints allow movements in many planes – up and down, to the side and all other planes. (iv) Hinge joints: These joints allow movement only in one plane like a door hinge and not more than 180 degrees. Examples, the fingers; the knee. The wrist is a double hinge joint.
(v) Gliding joints: These joints allow only a limited amount of movement of sliding nature of cartilages. For example, the joints in backbone. Gilding joint Q15. How can we get photograph of a bone? What is the use of such photographs? Ans. We can get photograph of a bone by a machine called X-ray machine. Doctors use these photographs to examine the dislocations and fractures in the bone.
Q16. Which important organ is fully protected inside the bones of the skull (head)? Ans. The bones of the skull form the structure similar to a box. The bones are joined with strong joints. It is not easy to break them. The bones of the skull protect the most important organ i.e. the brain. Q17. Try to eat your food without moving the lower jaw. Do you find this difficult to do? Ans. Without moving the lower jaw, we cannot chew the food. Without chewing we cannot engulp the food into food pipe. It would be difficult to digest unchewed food. Q18. Draw a labeled diagram of a ball and socket joint. Ans. Q19. Identify and label the different bones in the skeleton shown in the figure. Ans.