Question

Which of the following gas(es) function(s) as signaling molecule(s) in the human nervous system?

• A. Nitric oxide
• B. Carbon monoxide
• C. Helium
• D. Argon

Hint:

Nitric oxide (NO) is a key signaling molecule in the nervous system, while carbon monoxide (CO) also plays a role in certain physiological processes.

Answer 1

The Correct Option is A, B

Step 1: Understanding the role of gases in signaling. 
Certain gases like nitric oxide (NO) and carbon monoxide (CO) function as signaling molecules in the human nervous system. These gases are involved in regulating various physiological processes, such as vasodilation and neurotransmission. 
 

Step 2: Analyzing the options. 
- (A) Nitric oxide: Correct — Nitric oxide is a well-known signaling molecule in the nervous system, where it helps in processes like vasodilation and neurotransmission. 

- (B) Carbon monoxide: Correct — Carbon monoxide, though toxic at high concentrations, also acts as a signaling molecule in the body, particularly in the nervous system. 

- (C) Helium: Incorrect — Helium does not function as a signaling molecule in the nervous system. 

- (D) Argon: Incorrect — Argon is an inert gas and does not play a role in signaling in the nervous system. 
 

Step 3: Conclusion. 
The correct answer is (A) Nitric oxide and (B) Carbon monoxide. Both nitric oxide and carbon monoxide act as signaling molecules