Pollen trapped in mucus on nose hair, SEM

Coloured scanning electron micrograph (SEM) of pollen trapped in mucus on nose hair. Nose hair helps to protect against organisms and foreign debris from entering the nasal passages and lungs. Nose hair is larger than scalp or axillary hair in order to provide a larger surface area to collect foreign objects that pass through the nose. Nose hair is associated with the nasal epithelium and mucus of the nose (collectively known as the mucous membrane or mucosa). Specialized cells called goblet cells are present in the nasal epithelial layer of the nose. They are responsible for producing mucus that coats the surface of the nasal epithelial cells. The nose is one of the mucous membranes (mucosae) of the body that is involved in absorption and secretion. Mucus is a slippery secretion in the nasal passages consisting of a viscous colloid containing antiseptic enzymes and immunoglobulins. Phlegm is a type of mucus that is restricted to the respiratory tract. Foreign debris and organisms get trapped in the mucus. Nasal epithelial cells possess cilia (small hair-like threads) on their surface. The cilia beat rapidly back and forth pushing mucus back in towards the oropharynx where it can be either swallowed or ejected. Magnification: x340 when shortest axis printed at 25 millimetres., Creditline:DENNIS KUNKEL MICROSCOPY/SCIENCE PHOTO LIBRARY