Cilia

Definition

Cilia are hair-like structures that extend from the surface of many eukaryotic cells. They play crucial roles in movement and sensory functions.

5 Must Know Facts For Your Next Test

1. Cilia are made up of microtubules arranged in a '9+2' structure.
2. They can be motile (for movement) or non-motile (for sensory functions).
3. Motile cilia beat in a coordinated manner to move fluid or mucus across cell surfaces.
4. Non-motile cilia, also known as primary cilia, act as sensory organelles.
5. Defects in cilia function can lead to diseases known as ciliopathies.

Review Questions

• What is the structural arrangement of microtubules in cilia?
• What are the two main types of cilia and their functions?
• How do defects in ciliary function affect human health?

Related terms

Flagella: Whip-like structures used for cell movement, similar to cilia but usually longer and fewer per cell.

Microtubules:

Cylindrical structures that form part of the cytoskeleton and are essential for cell division, intracellular transport, and maintaining cell shape.

Basal Body:

A structure located at the base of a cilium or flagellum that organizes the microtubules within these organelles.