Human respiratory system includes: Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Lungs. Hands, legs, skin (except in amphibians) are not part of respiratory system.
The question asks which organ is not involved in respiration. To answer this, we need to understand the role of each organ listed in the options in the respiratory process.
Nose: The nose plays a crucial role in respiration. It serves as the main entry point for air, which is then filtered, warmed, and humidified before it travels down the respiratory tract.
Lungs: The lungs are the primary organs of the respiratory system, handling the exchange of gases (oxygen and carbon dioxide) with the blood. They are essential for respiration.
Trachea: Also known as the windpipe, the trachea is a vital component of the respiratory system. It provides a clear airway for air to enter and exit the lungs.
Hand: The hand is not involved in the process of respiration. It does not play any role in the respiratory system or in facilitating the exchange of gases.
Based on this analysis, we can conclude that the Hand is the organ not involved in respiration. Therefore, the correct answer is Hand.
