heterotrichous

Heterotrichous is a term used in biology to describe a type of ciliation, which is the presence of hair-like structures called cilia on the surface of cells. In heterotrichous ciliation, the cilia are of two different lengths. This type of ciliation is commonly found in the ciliated epithelium of the respiratory tract, particularly in the trachea and bronchi of mammals. The longer cilia, known as primary cilia, are responsible for moving mucus and debris away from the lungs, while the shorter cilia, known as secondary cilia, help to propel the mucus towards the pharynx. This dual-length ciliation system is crucial for maintaining the health of the respiratory system by clearing it of harmful particles and pathogens. Heterotrichous ciliation is also observed in other organisms, such as certain protozoa and algae, where it plays a role in locomotion and feeding.