What do the hairs in the nose and the mucus in the throat accomplish when someone inhales?

Answer 1

The air you breathe is full of tiny particles that have to be filtered out before the air can go into your lungs. The hair in your nose helps stop bits of dust and other debris from passing further into your nose. Further inside, the layer of sticky mucus catches the tiny particles that got through the hairs. The cells in your nose have microscopic hairlike projections on them called cilia. They actually beat back and forth about 16 times a second, and move the layer of mucus toward the back of your nose where it's normally swallowed. If something happens, like a particularly irritating particle gets caught in the mucus, you'll feel a tickle in your nose, triggering your sneeze reflex. It causes you to take in a big breath of air, and forcefully expel it through your mouth and nose, taking some mucus (and hopefully the irritant) with it. The mucus in your throat does the same filtering job, and irritations there cause coughing. The mucus also helps moisten the air, to make it better to breathe into your lungs.

Answer 2

Well the mucus is on the tiny hairs, called cilia. They are there to prevent the intake of foreign particles, if one is to get in the cilia will attempt to sick to it so it does not cause harm to your body. It's part of your immune system.