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]
(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 $=95 mmHg, PCO 2=40 mmHg$ )
