Question map
In the human body, blood flows through a process of double circulation. Which one of the following statements is true in this regard ?
Explanation
In the human double circulation system, blood passes through the heart twice per circuit. Oxygenated blood from the lungs returns to the heart via the pulmonary veins and enters the left atrium [1]. From the left atrium, it is transferred to the left ventricle, which then pumps this oxygen-rich blood through the aorta to the rest of the body [3]. Conversely, deoxygenated blood from the body enters the right atrium and moves to the right ventricle, which pumps it to the lungs for re-oxygenation [2]. Therefore, statement 1 is correct as oxygenated blood specifically reaches the left side of the heart from the lungs. Statements 2, 3, and 4 are incorrect because the left side of the heart handles oxygen-rich blood, while the right side handles oxygen-poor blood destined for the lungs [1].
Sources
- [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Our pump — the heart > p. 92
- [2] https://www.nhlbi.nih.gov/health/heart/blood-flow
- [3] https://www.ncbi.nlm.nih.gov/books/NBK279250/