Read the two statements provided and select the correct option:
I. Veins have valves which prevent the backflow of blood.
II. Flow of blood is not very fast in veins as there is low pressure.
Important Questions on Respiration and Circulation
Statement (S): The sinoatrial node is called 'Pace-maker'.
Reason (R): The sinoatrial node contains specialised cardiomyocytes and generates action potentials without any external stimuli.
The correct answer is
Reason (R): In the heart of the human embryo, oxygenated and deoxygenated blood is completely separated.
Given below are sets of five terms each. Rewrite the terms in correct order in a logical sequence beginning with the first word that is underlined:
Artery, Capillaries, Venule, Vein, Arteriole.
| Column – I | Column – II | ||
| a. | Tricuspid valve | i. | Between left atrium and left ventricle. |
| b. | Bicuspid valve | ii. | Between the right ventricle and pulmonary artery. |
| c. | Semilunar valve | iii. | Between the right atrium and right ventricle. |
Which one of the following graphs best describes the Blood Pressure (BP) change when blood moves from aorta to capillaries?
Blood capillaries are made of
A vein possesses a large lumen because
Pulmonary artery differ from pulmonary vein in having:
Given below are three statements (I–III) regarding the human blood circulatory system.
(I) In the treatment of angina pectoris, nitrous oxide and nitroglycerine are used.
(II) Veins have thinner walls and broader lumen than arteries.
(III) Artificial pacemakers are used in arrhythmia.
How many of the above are correct statements?
