Q. 114.1( 126 Votes )
Describe the function of the heart.
The heart is an organ act as a pump for the transport of blood and various other substances.
The human heart is divided into four chambers. The upper two chambers are called right and left atrium and the lower two chambers are called the right and left ventricles.
The right atrium receives the blood rich in carbon dioxide from the body. Blood from right atrium enters the right ventricle, which contracts and pumps the blood to the lungs.
On the other hand, blood from the lungs returns to the left atrium. From the left atrium, blood enters the left ventricle.
Left ventricle contracts and pumps the blood to all parts of the body. Hence, the rhythmic contraction and expansion of various chambers of the heart maintain the transport of oxygen to all parts of the body.
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Fill in the blanks of the following paragraph using just two words – arteries and veins.
___(a)___ carry oxygen-rich blood from the heart to all parts of the body and ___ (b)___ carry carbon dioxide-rich blood from all parts of the body back to the heart. ___ (c)___ have thin walls and __ (d)___ have thick elastic walls. Blood flows at high pressure in ___ (e)____. Valves are present in __ (f) ___ which allow blood to flow only towards the heart. __ (g)___ divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form ____ (h)_____.NCERT - Exemplar Science
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Fill in the blanks.
i. The blood from the heart is transported to all parts of the body by the _________.
ii. Hemoglobin in present in ______ cells.
iii. Arteries and veins are joined by a network of _____.
iv. The rhythmic expansion and contraction of the heart is called_____.
v. The main excretory product in human beings is ______.
vi. Sweat contains water and ________.
vii. Kidneys eliminate the waste materials in the liquid form called______.
viii. Water reaches great heights in the trees because of suction pull caused by _______.NCERT Science
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(a) Name the only artery that carries carbon dioxide-rich blood.
(b) Why is it called an artery if it does not carry oxygen-rich blood?NCERT - Exemplar Science
The absorption of nutrients and exchange of respiratory gases between blood and tissues takes place in –NCERT - Exemplar Science
Observe Figure 11.2 and answer the given questions: Fig 11.2
(a) Name the instrument.
(b) Label the parts A, B, and C.NCERT - Exemplar Science