Difference Between Cilia and Stereocilia (With Table)

The human body is one of the most complex structures of the world, where each cell and organ starting from the tiniest cerebellum’s granule cell to the biggest muscle of the gluteus maximus, i.e., the buttock muscle has its own work and responsibilities to make the body function actively on a regular basis. 

The plasma membrane of the free end gets modified to form three types of functional junctions microvilli, Stereocilia, Cilia, or kinocilia. Stereocilia and Cilia are cytoplasmic projections. Though they both are confused for each other, in reality, Stereocilia is more similar to microvilli.

Cilia vs Stereocilia

The difference between Cilia and Stereocilia is that Cilia can be motile or non-motile but are mostly motile while Stereocilia are non-motile, meaning Cilia have the ability to move on their own while Stereocilia can not propel by themselves. Also, Cilia are smaller in comparison to Stereocilia. 

Cilla is small projections that arise from basal granules of the body. Basal granules are a type of cellular membrane structure. They are mostly contractile motile. The function of this fibrous process is to move particles, primarily mucus, in a specific direction.  

Stereocilia is a mechanosensing organelle that plays the role of increasing the in-between surface cells so that it can help them in absorption and secretion. Since there is a 9+2 arrangement in Stereocilia, they are also absent in the basal granules.

Comparison Table Between Cilia and Stereocilia

Parameters of Comparison Cilia Stereocillia 
Definition  Cilia, plural of Cilium, are a group of organelle that provides propulsion. Stereocilia are non-motile modifications of the cell.  
Another name Kinocilia  Stereovilli 
Function(s) Provide locomotion, i.e., to Move cells into a regular movement. Turn physical force into an electric signal in the process of hearing and absorption, secretion of excess fluid in the hollow human. 
Arrangement  9+2 arrangement is present. 9+2 arrangement is absent. 
LocationIn the middle ear, lungs, and respiratory tract.  In the hair cells of the inner body, ductus deferens and epididymis. 

What is Cilia?

The name “Cilia” came from a Latin word that translates into “the edge of the eyelids and of the eyelashes.” It was first discovered in 1675 by Anthony Van Leeuwenhoek, making it the first known cellular organelle. Cilia are small hair-like structures. These cells are many in numbers, to be approx., hundreds per cell. It originates all over the human body or on the peristomial region/end. A single unit of it would be called Cilium. 

The arrangement of cilia fuses with each other to form membranelles and cirri or undulating membranes. The movement is fast, in a pendular type movement or sweeping movement. They are the fastest protozoans. These are located on the inner surface of the hollow organ. 

Their main function is to protect the body from germs and bacteria entering the body by the mucus of the airways and from the lungs by propelling microbes. Like the respiratory track, whenever oxygen is inhaled into the body, there are certain dirt particles in it. There comes the use of mucus, and in that, Cilia helps in tracking those dirt particles.

What is Stereocilia?

Stereocilia is a specialization of the free surface. They are the mechanosensing organelles of hair cells, which means it is a kind of receptor that has the ability to sense its microenvironment. Though Stereocilia shares its name with Cilia, the tissues share more features to microvilli than Cilia. Its structure is long and is non-motile. 

They are located at the Epididymis, in the inner ear of the hearing guard, and in Vas deferens. It can also be found in the lining of the urethra. The main function is plays of increasing the surface area for the process of secretion and absorption. Unlike Cilia, Stereocilia does not have any ultra arrangement.

The Stereocilia of the inner ear is about 10–50 micrometers in length. They respond to fluid motions not only in humans but for various types of other animals s well. The sound above a certain decibel can damage the Stereocilia that lies in the inner ear. But according to the new studies, damaged hearing loss can be restored in the future that is caused by damaged inner ear Stereocilia.

Main Differences Between Cilia and Stereocilia 

  1. Stereocilia is like Cilia, but their projections are long, whereas Cilia’s projections are small in comparison to Stereocilia.  
  2.  Stereocilia are non-mobile or non-motile. On the other hand, Cilia can be motile or non-motile but are mostly motile in number.  
  3.  Their locations located in the human body are also different. Cilia is present in the basal granules of the body, while Stereocilia are present in the inner ear and the male reproductive parts that are: Vas deferens and Epididymis. 
  4. The functions of these particular projections are also different. The main function of Cilia is to sweep the mucus in a particular direction, while the function of Stereocilia is to increase the surface area of the cell that allows greater absorption.  
  5. Cilia is a cytoplasmic process, and Stereocilia is a protoplasmic process, meaning that it arises from the plasma membrane. 
  6. A Cilium has a 9+2 ultra-structure that means that it has 9 pairs of microtubules that are fused and 2 pairs of unfused microtubules. While Stereocilia has no ultrastructure. 

Conclusion 

Both Cilia and Stereocilia are epithelial tissues. They are long in length and are small in size. The main function of Cilia is the process of carrying out locomotion in the body in a certain direction, while the function of Stereocilia is to increase the surface area of cells to help in absorption. Cilia are also the oldest known organelle. 

To an average person, it is rather hard to differentiate between the two, but once if one looks closely and pay attention to the anatomy of the epithelial tissues, it will be seen that Cilia and Stereocilia have different functions, are located at different parts at the body and are quite diverse from each other. 

References

  1. https://books.google.co.in/books?id=yrdqAAAAMAAJ&q=difference+between+cilia+and+stereocilia&dq=difference+between+cilia+and+stereocilia&hl=en&sa=X&ved=2ahUKEwjNyaK9qLXwAhXSbCsKHdXpBf4Q6AEwAHoECAMQAw
  2. https://www.sciencedirect.com/science/article/pii/S0006349507713711
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