This human body video lesson is all about our nose and how we breathe, smell and taste. Learn about the nostrils, septum, dorsum nasi, nasal cavity, nasal passages, trachea, mucus membranes, cilia, olfactory nerves, odor receptors and keeping your nose clean. Snakes smell through their mouths, and flies have chemosensory hairs. Smell is a powerful memory tool and what we taste is determined by what we smell.