Movement of mucus Cilia in the nose move the mucus formed there towards the throat where it is swallowed and digested in the stomach. In cold weather, this process slows and the mucus sometimes gathers in the nose and drips or dribbles out – a winter runny nose. Particles larger than 4mm in diameter usually become trapped in mucus in the nose and rarely get any further down the airways. The nasal mucosa has many sensory nerve endings and large particles irritate these nerves, stimulating a sneeze – a violent burst of air – which expels the particles along with mucus.