What is the primary function of cilia?

Cilia are hair-like structures that extend from the surface of many types of cells. Their primary function revolves around movement or sensation. Cilia can move in coordinated waves to help propel fluids and particles across cell surfaces, as seen in the respiratory tract where they help move mucus out of the lungs, facilitating cleaning and protection against pathogens. Additionally, cilia play a significant role in sensory perception, particularly in cells that are involved in the detection of environmental signals.

Although other functions like absorbing nutrients, cell reproduction, and protein synthesis are critical for cell function, they are not the primary roles associated with cilia. Absorption is typically handled by microvilli in absorptive cells, while cell reproduction and protein synthesis are processes managed by other cellular organelles and structures. The unique structure and functionality of cilia underscore their key role in movement and sensory functions in various biological systems.