Describe the function of the heart.
HEART: The heart is an organ which pumps blood to all the parts of our body through a network of tubes called blood vessels. Heart beats continuously to circulate blood in the body. The heart works like a pump non-stop throughout our life. It is located in the chest cavity slightly towards the left side. The heart lies between the two lungs and above the diaphragm and its size is roughly equal to our fist. The heart is made up of special muscle called ‘cardiac muscle’ but it is not solid muscle. The heart is hollow inside. The heart has four compartments called ‘chambers’. The upper two chambers of heart are called atria (singular of atria is atrium) and the lower two chambers of heart are called ventricles. On the left side of the heart are left atrium and left atrium and left ventricle. On the right side of the heart are right atrium and right ventricle. Right atrium receives carbon dioxide rich blood from the body. Blood from right atrium enters the right ventricle, which contracts and pumps the blood to the lungs. On the other hand, oxygen rich blood from the lungs returns to the left atrium. From the left atrium, blood enters left ventricles. Left ventricles contracts and pumps the blood to all parts of the body.
Human heart diagram:
Functions of heart: The main functions of heart-
1. Pumping oxygenated blood to the other body parts.
2. Pumping hormones and other vital substances to different parts of the body.
3. Receiving deoxygenated blood and carrying metabolic waste products from the body and pumping it to the lungs for oxygenation.
4. Maintaining blood pressure.
Popular Questions of Class 7 Science
- Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
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Sketch the cross section of soil and label the various layers.
- Q:-
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human bodyDown
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water - Q:-
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
- Q:-
Sketch the reproductive parts of a flower.
- Q:-
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil. - Q:-
Describe how crystals of copper sulphate are prepared.
- Q:-
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus - Q:-
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
Recently Viewed Questions of Class 7 Science
- Q:-
Salma takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school.
- Q:-
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil. - Q:-
Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.
- Q:-
Consider the following statements:
(a) Both acids and bases change colour of all indicators.
(b) If an indicator gives a colour change with an acid, it does not give a change with a base.
(c) If an indicator changes colour with a base, it does not change colour with an acid.
(d) Change of colour in an acid and a base depends on the type of the indicator.Which of these statements are correct?
(i) All four (ii) a and d (iii) b and c (iv) only d - Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Match the words of Column I with those given in Column II:
Column I Column II
1. Scouring (a) Yields silk fibres
2. Mulberry leaves (b) Wool yielding animal
3. Yak (c) Food of silk worm
4. Cocoon (d) Reeling
(e) Cleaning sheared skin - Q:-
Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?
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The distance between two stations is 240 km. A train takes 4 hours to cover this distance. Calculate the speed of the train.
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One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be
(a) 80°C (b) more than 50°C but less than 80°C
(c) 20°C (d) between 30°C and 50°C - Q:-
Describe the various ways by which seeds are dispersed.
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