Question

Which vertebrate organ receives only oxygenated blood?
A. Gill
B. Lung
C. Spleen
D. Liver

Answer 1

Hint: Deoxygenated blood is transferred to the organs responsible mainly for oxygenation.

Complete answer:
The spleen is the organ that receives only oxygenated blood.
- The spleen is supplied by the splenic artery that is a branch of the celiac trunk that arises from the aorta. It supplies only oxygenated blood to the spleen. On the other hand, the splenic vein carries the deoxygenated blood away from the spleen and drains it into the hepatic portal vein.
- Spleen is situated in the upper left quadrant of the abdomen. It is mainly responsible for filtering the blood i.e., removing dead RBCs and pathogens from the blood. So, it is also known as ‘the Scavenger of RBC's'.
- Gills receive impure blood for oxygenation in fishes and amphibians.
- Lungs receive impure blood through the pulmonary artery from the heart in order to oxygenate it.
- The liver receives deoxygenated blood laden with food through the hepatic portal system from the small intestine and spleen and further sends it to the heart.

So, the correct option is ‘spleen’.

Note:
- The abdomen is divided into nine quadrants for a better understanding and description of its contents.
- The spleen is part of our lymphatic system, which fights infection and keeps our body fluids in balance. It contains specialized white blood cells i.e. ‘Kupffer cells' that fight germs.
- The brain also receives only oxygenated blood and even a small amount of increased $CO_2$ can cause the brain to dysfunction.