STD-6, CHAPTER-9, CIRCULATORY SYSTEM, EXTRA OBJECTIVE QUESTION ANSWERS

1. Where is the heart located?

Ans: The heart is located, slightly towards the left, in the chest cavity.

2. Heart is made up of _____.

Ans: muscle (a special type of muscle known as cardiac muscle)

3. The heart is divided into ____ equal halves.

Ans: 2

4. Each half of the human heart is divided into ____ chambers.

Ans: 2

5. There are ____ chambers in the human heart.

Ans: 4

6. The upper two chambers of the human heart are called as _____.

Ans: Auricles or Atriums

7. The lower two chambers of the human heart are called as _____.

Ans: ventricles

8. Name the four chambers of the human heart.

Ans: The four chambers of the human heart are left auricle, left ventricle, right auricle and right ventricle.

9. In which side of the human heart, do blood rich in carbon dioxide flow?

Ans: Right side

10. In which side of the human heart, do blood rich in oxygen flow?

Ans: Left side

11. The _____ side of the heart is bigger.

Ans: left

12. What is the main function of the heart?

Ans: The main function of the heart is to pump blood and keep it moving in the blood vessels.

13. What is heart beat?

Ans: A heart beat is the sound the heart makes when the heart valves open and close.

14. Heart beat can be heard by using _____.

Ans: stethoscope

15. The average heart beat rate of a person is ____.

Ans: 72 times per minute

16. When does the heart beat rate increase?

Ans: The ‘heart beat rate’ increases during heavy exercise, excretion or when a person is excited.

17. The heart of a new born baby beats _____ times per minute.

Ans: 140 times

18. The heart of a three year old child beats ____ times per minute.

Ans: 100 times

19. What are blood vessels?

Ans: The system of tubes through which blood moves around in the living body, are called the blood vessels.

20. There are _____ types of blood vessels.

Ans: three

21. Name the three types of blood vessels.

Ans: The three types of blood vessels are- the arteries, the veins and the capillaries.

22. Name the blood vessels which take blood away from the heart.

Ans: arteries

23. Name the blood vessels which take blood towards the heart.

Ans: veins

24. Generally arteries carry blood rich in ___.

Ans: oxygen

25. Generally veins carry blood rich in _____.

Ans: carbon dioxide

26. Distinguish between arteries and veins.

Ans:

ARTERIES	VEINS
1. These blood vessels take blood away from the heart.	1. These blood vessels take blood towards the heart.
2. Generally arteries carry blood rich in oxygen.	2. Generally veins carry blood rich in carbon dioxide.
3. Arteries are thick walled.	3. Veins are thin walled
4. Arteries are seated deep inside the skin.	4. Veins are superficial (located just under the skin)

 

27. What are capillaries?

Ans: Capillaries are fine blood vessels which connect arteries to veins.

28. The arteries, and veins, are connected to each other by fine vessels, called the ______.

Ans: Capillaries

29. What is blood?

Ans: Blood is a type of tissue made up of cells like RBCs, WBCs and Platelets. It is a red thick fluid.

30. Blood is red in colour due to the presence of _____.

Ans: Haemoglobin

31. Why the blood of insects is not red in colour?

Ans: The insects have no haemoglobin in blood. So, they have blue, green or colourless blood.

32. Name the components of blood.

Ans: The components of blood are- RBCs, WBCs and Platelets.

33. RBCs stand for _____.

Ans: Red Blood Cells

34. WBCs stand for _____.

Ans: White Blood Cells

35. Name the four types of blood groups.

Ans: The four types of blood groups are: A, B, AB and O.

36. What are the functions of blood?

Ans: The functions of the blood are to:

i) transport oxygen, food materials and hormones to all parts of the body.

ii) take back carbon dioxide, from all parts of the body, to the lungs.

iii) protect the body from diseases and other infections.

iv) help to maintain the body at a constant temperature.