This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System Pa 1, Subject name: Physiology
"Raptures of the depth" are caused by: 
Select and explain. 
A. CO narcosis, B. CO2 narcosis, C. N2 narcosis, D. O2 toxicity
C: N2 narcosis
Answer: C: N2 narcosis 
Explanation: A diver working at the depth for prolonged periods has gases in the body getting compressed and dissolved in body fluids. Major gas being N2, its dissolution in the body fluids, and paicularly in the myelin sheaths of CNS neurons, results in the 'raptures of the depth'.