Body Fluids and Circulation Question 60

60. Figure shows blood circulation in humans with labels A to D. Select the option which gives correct identification of label and functions of the part:

[NEET Kar. 2013]

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(a) A-Artery - thick walled and blood flows evenly

(b) B-Capillary - thin without muscle layers and wall two cell thick

(c) $C$ - Vein - thin walled and blood flows in jerks/spurts

(d) D - Pulmonary vein - takes oxygenated blood to heart $PO_2=95 mmHg$

Show Answer

Answer : d

Hints & Solutions

(d) Artery is a blood vessel which receives blood from heart, has elastic thick wall showing jerky movements due to pumping activity of heart. Vein is a blood vessel which carries blood towards the heart, has wider lumen with internal valves where blood flows smoothly and slowly. Blood capillary is a very fine blood vessel which has a single layered wall. Pulmonary veins are the only veins which carry oxygenated blood. (PO2 $=95 mmHg, PCO 2=40 mmHg$ )