Which part of the body is primarily responsible for smelling and breathing?

The nose is primarily responsible for both smelling and breathing due to its anatomical structure and functions. It contains olfactory receptors that detect odor molecules, allowing for the sense of smell. The nasal cavity is lined with mucus membranes that trap particles and pathogens while also humidifying the air we inhale.

When breathing, the nose filters and warms the air before it passes into the lungs, which is crucial for maintaining optimal respiratory health. In contrast, the mouth primarily facilitates breathing and is also involved in the digestion of food but does not play a significant role in the sense of smell. The lungs are essential for gas exchange—oxygen intake and carbon dioxide expulsion—but do not contribute directly to the olfactory process. The throat serves as a passageway for air and food but does not actively participate in the senses of smell or the initial intake of air in a filtering manner like the nose does.