What is the Difference Between Merkel Cells and Meissner Corpuscles

The main difference between Merkel cells and Meissner corpuscles is that the Merkel cells respond to the light touch whereas the Meissner corpuscles respond to the low-frequency vibrations. Furthermore, Merkel cells are slow-adapting while Meissner corpuscles are rapidly-adapting. Moreover, Merkel cells are unencapsulated while Meissner corpuscles are encapsulated. 

Merkel cells and Meissner corpuscles are two of the four types of primary tactile mechanoreceptors in human skin. They are sensitive to stimuli, which physically deform their plasma membrane. However, the other two types of primary tactile mechanoreceptors occur deeper in the skin. They are Ruffini endings and Pacinian corpuscle. The fifth type of primary mechanoreceptors is the Krause end bulbs, which only occurs in the specialized regions of the skin. 

Key Areas Covered 

1. What are Merkel Cells
     – Definition, Location, Response
2. What are Meissner Corpuscles
     – Definition, Location, Response
3. What are the Similarities Between Merkel Cells and Meissner Corpuscles
     – Outline of Common Features
4. What is the Difference Between Merkel Cells and Meissner Corpuscles
     – Comparison of Key Differences

Key Terms 

Meissner Corpuscles, Merkel Cells, Light Touch, Low-Frequency Vibrations, Primary Tactile Mechanoreceptors 

What are Merkel Cells 

Merkel cells are one of the two types of primary tactile mechanoreceptors located near the upper surface of the skin. They occur in skins with hair and without hair. The skin without hair is known as the glabrous skin; this type of skin occurs in the palms, fingers, soles of the feet, and lips. Moreover, fingertips and lips especially contain many Merkel cells.  

Figure 1: Merkel Cell

Furthermore, the nerve endings of the Merkel cells are unencapsulated and slow-adapting. They respond to light touch. Here, the light touch is a discriminative touch, a type of light pressure, which pinpoints the location of the stimulus. Although the receptive field of Merkel cells is small, it has a well-defined border.  

What are Meissner Corpuscles 

Meissner corpuscles are the other type of primary tactile mechanoreceptors located near the upper surface of the skin. They mainly occur in the glabrous skin on the eyelids and fingertips. More importantly, Meissner corpuscles respond to low-frequency vibrations or flutter. They also respond to fine touch and pressure.  

Figure 2: Meissner Corpuscle

However, the nerve endings of the Meissner corpuscles are encapsulated and fluid-filled. Moreover, they adapt rapidly to the stimulus.  

Similarities Between Merkel Cells and Meissner Corpuscles 

• Merkel cells and Meissner corpuscles are two types of primary tactile mechanoreceptors in the human skin. 
• Both are nerve endings that occur just below the epidermis of the skin. Therefore, they are the two types of primary tactile mechanoreceptors located toward the surface of the skin. 
• Moreover, they consist of mechanically-gated ion channels, which open and close based on the stimuli. 

Difference Between Merkel Cells and Meissner Corpuscles 

Definition 

Merkel cells refer to cells that occur in the basal part of the epidermis, characterized by dense granules in its cytoplasm, closely associated with the unmyelinated tip of a nerve fiber, and probably function in tactile sensory perception. Meissner corpuscles refer to any of the small elliptical tactile end organs in hairless skin containing numerous transversely placed tactile cells and fine flattened nerve terminations. 

Type of Sensation 

The main difference between Merkel cells and Meissner corpuscles is that Merkel cells respond to light touch while Meissner corpuscles respond to low-frequency vibrations. 

Adaptation 

Adaptation is also a major difference between Merkel cells and Meissner corpuscles. Merkel cells are slow-adapting while Meissner corpuscles are rapidly-adapting. 

Encapsulation 

Furthermore, Merkel cells are unencapsulated while Meissner corpuscles are encapsulated. Hence, this is another difference between Merkel cells and Meissner corpuscles. 

Location 

Also, Merkel cells occur in the upper surface of the skin with hair or glabrous while Meissner corpuscles occur in the glabrous skin on eyelids and fingertips. 

Conclusion 

Both Merkel cells and Meissner corpuscles are primary tactile mechanoreceptors located near the upper surface of the skin. Merkel cells respond to light touch while Meissner corpuscles respond to low-frequency vibrations. Thus, the main difference between Merkel cells and Meissner corpuscles is the type of stimuli to which they respond.

References:

1. “Somatosensation|Boundless Biology.” Lumen Learning, Lumen, Available Here

Image Courtesy:

1. “Blausen 0805 Skin MerkelCell” By “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia
2. “Blausen 0808 Skin TactileCorpuscle” By “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia