What are Cilia?

Paramecium with eyelashes.

The term eyelashes is Latin for “eyelashes”. Common in single-celled organisms, this hair-like structure moves to move the cell or something around it. Cilia are also present in most cells in the human body. Some body tissues, such as the fallopian tubes in women and the trachea, also have a special type of cilia that help transport substances along the surface of the tissues.

Types of eyelashes on the body

Three Paramecium caudatum, which have cilia.

In the body, tissue surface cilia are responsible for protecting a person from germs in the lungs and for pushing an egg down the fallopian tube, among other tasks. These eyelashes are called mobile eyelashes and they are found in groups and beat in waves. Primary cilia, on the other hand, are usually found only one at a time in cells.


Cilia is the Latin term for eyelashes.

The structure of a single cilia is very similar to a tube and its long fibers are called microtubules. These microtubules often pair up to form doublets, which in turn form a ring. The cross section of microtubule doublets looks like Figure 8, because the two microtubules come together along a line. Nine doublets form the largest ring in what is known as the 9-2 pattern. When kinesin attaches to one side of the gibbons and not the other, the cilium flexes and curves, similar to the way a person’s skeletal muscles contract.


A woman’s fallopian tubes contain celia which carries the egg.

Single-celled eukaryotes, which are organisms with cells that have a nucleus, often use cilia to move through fluid. This type of organism is surrounded by a cytoskeleton, made of filaments of proteins that allow the cell to maintain its shape. A cilium attaches to the cell’s cytoskeleton with a basal body, in the same way that a root attaches hair to human skin.

See also  What is a monocular microscope? (with photos)

Flagella are cilia-like strands of hair that can be found in bacteria.

The rhythm of undulating cilia is controlled by centrioles, which are organelles located within the cell wall. Mitochondria, other units within the cell, provide adenosine triphosphate (ATP), a source of cellular energy, to the cilia. ATP directs the chemical kinesin to bind to certain parts of the cilia that control their movement. Thus, cilia are able to flap or essentially swim in a viscous liquid.


Some of the eukaryotes found in ferns use cilia and flagella.

Similar to cilia, flagella are longer, usually found in one or two, like a sperm’s tail. They share many features with cilia, but they also occur in prokaryotes, which are organisms with cells that do not contain a nucleus. Some eukaryotes that use cilia and flagella to move are also found in ferns, algae, bacteria, and inside many animals. This adaptation originally allowed independent cellular creatures such as paramecium to move around in search of food, rather than waiting for food to reach them. Cells that are part of larger systems continued to use cilia to their advantage.

Leave a Comment