Each major organ of the body comprises millions of different components and tissues. Each tissue is made up of cells, the fundamental unit of life.
The cell is further divided into various cell organelles with different functions. The organelles include the plasma membrane, mitochondria, cilia, etc. The cilia is a cell organelle present in mostly all types of cells except the blood cells. Let us study the cilia functions.
Cilia
The plural form of the cilium is cilia. The cilium is a Latin word for eyelash. Since this cell organelle looks like an eyelash, it is named so. The cilia are found on the eukaryotic cells. It looks like grass growing out on the cell.
Since the cilia are part of the Eukaryotic cells, let us learn about the Eukaryotic cells briefly. It will also help us understand the cilia functions.
Eukaryotic cells
Eukaryotic cells are advanced cells with a nucleus enclosed in a nuclear membrane. The prokaryotic cells contain membrane-bound organelle comprising the Golgi apparatus, mitochondria, chromosomes and cilia. Unicellular and multicellular organisms can be made up of Eukaryotic cells.
Let us study the functions of cilia from the Eukaryotic cells.
Types of Cilia
The cilia in the Eukaryotic cells can be divided into two types as follows.
- The motile cilia
- The non-motile cilia
The non-motile cilia are regarded as the primary cilia, and the non-motile cilia act as sensory components of the cell. The motile cilia are usually found along the flagella and are somewhat similar in structure. The cilia’s function of the immotile type is to communicate signals from other cells or the environment.
Primary Cilia and its function
The non-motile cilia are called the primary cilia as they are found on almost all cells of the animals. However, they are absent from the blood cells of the animals. The number of cilia found on each cell is usually equal to one. Therefore, in the olfactory sensory neurons, which help with the sense of smell, about ten cilia are present in each cell in the odorant receptors.
Although the cilia function in the cell is quite essential, the primary cilia were considered vestigial organs for many centuries. The primary cilia get assembled during the G1 phase before the mitosis.
The cilia functions of primary cilia are as given below;
- Coordination of cellular signal pathways
- Coupling signals to ciliary motility
- Acting as a messenger between other cells as the environment
Motile Cilia
The Eukaryotic animals with large bodies also contain the motile cilia and the primary cilia. Numerous motile cilia are present on the cell surface. The motile cilia are found in the following places.
- In humans, the motile cilia are present on the epithelium lining of the lungs. The cilia function of the cilia here is sweeping the mucus and dirt out of the lungs.
- In the case of the female mammals, the cilia lined up the fallopian tube. The cilia function here moves the ovum from the ovaries to the uterus.
Non-classical Cilia
These are the third type of cilia that are not considered in classification as they do not occur in many cells. Like the primary cilia, the non-classical cilia do not have any central apparatus. These cilia are components of the epithelial cells of the choroid plexus.
The function of the cilia is to change structure when introduced to hot temperatures and become sharp. Their movement is slow, but they are found in large numbers together.
The main function of the primary cilia, which are present in the Eukaryotic cells, is to sense the environment around them. The cilia send signals to the remaining cell and help maintain the cellular environment by the outside environment.
The cilia act as a messenger and give information from one cell to its neighbouring cells.
In a mouse embryo, the cilia’s function is to direct the flow of the extracellular fluid.
Such are the functions of various types of cilia in various organisms.
Conclusion
The cell, which is the fundamental unit of life and forms the organs that lead to the formation of organisms, comprises multiple cellular organelles. These organelles include the chromosomes, mitochondria, cytoplasm, cilia, etc. The cilia are shaped like eyelashes.
There are three types of cilia: motile cilia, non-motile cilia and non-classical cilia.
The primary cilia are found on most of the cells of the animals except for the blood cells. The non-motile cilia are found in organisms with large bodies. The cilia’s function is primarily to act as messengers between various cells and the environment. The cilia’s function of the immotile type is to communicate signals from other cells or the environment.