Cilia are tiny, hair-like structures found on the surface of many cells. They serve various functions, but two of the primary uses of cilia are:
- Movement: Cilia can beat in coordinated waves to help move fluids, mucus, and other substances across the cell surface. For example, in the respiratory tract, cilia help to push mucus out of the lungs, trapping pathogens and debris.
- Sensory Functions: Cilia also play a crucial role in sensing the environment. They can detect chemical signals, changes in fluid movement, and other stimuli, transmitting this information to the cell to initiate appropriate responses.
In summary, cilia are essential for both the movement of materials across cell surfaces and for sensory functions that help cells react to their environment.