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प्रश्न
Answer in only one sentence of the following question:
Mention the role of the pacemaker in human heart.
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उत्तर
- The Sinu-auricular (SA) node is the pacemaker of the heart.
- It generates wave of contraction which spread along the wall of atria and bring about their contraction.
- It has highest degree of rhythmicity and is the first to originate the cardiac impulses and determine the rate of heart beat.
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संबंधित प्रश्न
The human body has an organ A which acts as a double pump. The oxygenated blood coming from the lungs through blood vessel B enters the upper left chamber C of the double pump. When chamber C contracts, then blood goes into the lower left chamber D. The contraction of chamber D forces the blood to go into a blood vessel E which supplies oxygenated blood to all the organs of the body (except the lungs). The deoxygenated blood coming out of the body organs is taken by a blood vessel F to the right upper chamber G of the pumping organ. Contraction of chamber G forces the deoxygenated blood into the right lower chamber H. And finally, the contraction of chamber H sends the deoxygenated blood into the lungs through blood vessel I.
- What is organ A?
- Name the blood vessel (i) B (ii) E (iii) F, and (iv) I.
- What are chambers (i) C, and (ii) D?
- What are chambers (i) G and (ii) H?
Multiple choice question. Tick (✓) the correct choice:
The heartbeat is measured by an instrument called
- thermometer
- sphygmomanometer
- stethoscope
- none of the above
The diagram given alongside represents the human heart in one phase of its activity. Study the same and then answer the question that follow:
Name the phase.
Name the following:
The phase of the cardiac cycle in which auricle contracts.
Why is the SA node called the pacemaker of the heart?
Given alongside is a diagram of the external features of the heart.
(i) Name the parts ‘1’ to ‘7’.
(ii) What happens if the coronary artery gets an internal clot?
(iii) Which type of blood does part ‘5’ carry?
(iv) Mention one structural difference between part ‘5’ and ‘4’.
Name the Following
The study of blood vascular system including arteries, veins and heart.
Mention the artery which supplies blood to the heart muscle.
____________ branches from bundle of His and forms a network in ventricular walls.
Analogy:
Skeletal muscle: Muscle of arm.
Cardiac muscle: ______.
