What is the Difference Between Peristalsis and Segmentation

The main difference between peristalsis and segmentation is that peristalsis is a one-way motion in the caudal direction, whereas segmentation is responsible for the movement in both directions, allowing a greater mixing. Furthermore, peristalsis occurs by the contractions of the circular muscles while segmentation occurs due to the rhythmic contractions of the longitudinal muscles. Also, peristalsis mainly occurs in the esophagus, while segmentation mainly occurs in the small and large intestine.  

Peristalsis and segmentation are two types of muscular movements that occur in the gastrointestinal tract. They are responsible for the movement of food through the gastrointestinal tract. 

Key Areas Covered 

1. What is Peristalsis
     – Definition, Characteristics, Importance
2. What is Segmentation
     – Definition, Characteristics, Importance
3. What are the Similarities Between Peristalsis and Segmentation
     – Outline of Common Features
4. What is the Difference Between Peristalsis and Segmentation
     – Comparison of Key Differences

Key Terms 

Gastrointestinal Tract, Muscular Movements, Peristalsis, Segmentation

What is Peristalsis 

Peristalsis is a radially symmetrical muscular movement responsible for the propagation of materials. Generally, it is more common in the esophagus of the gastrointestinal tract, propelling a ball of food from the mouth to the stomach. Basically, the contraction of the circular muscles of the wall of the esophagus is responsible for peristalsis. Moreover, peristalsis produces a one-way movement.

Figure 1: Peristalsis

Furthermore, primary peristaltic wave occurs first with the entrance of the bolus into the esophagus after swallowing. And, this wave lasts for about 8-9 seconds. However, if the bolus gets stuck or moves slowly, a secondary peristaltic wave occurs around the bolus with the stimulation of a local reflex. Therefore, it forces the bolus down. 

What is Segmentation 

Segmentation is a type of local contractions of circular muscles of the gastrointestinal tract. In general, it mainly occurs in the small intestine. However, these localized contractions are responsible for the back and forth movement of food. It allows the continuous subdivision, breaking up, and mixing the contents. Therefore, segmentation facilitates the mixing of food with the secretions of the small intestine while allowing mechanical digestion. Thus, it both facilitates absorption of nutrients through digestion as well as the propagation of food towards the end of the gastrointestinal tract slowly.

Figure 2: Digestive Process

Similarities Between Peritstalsis and Segmentation 

• Peristalsis and segmentation are two types of muscular contractions occur in the gastrointestinal tract. 
• They are involuntary muscular movements. 
• Furthermore, they are responsible for the movement of food through the gastrointestinal tract. 
• They are also responsible for the mechanical digestion of food as well as the mixing of food with different secretions of the gastrointestinal tract. 
• Moreover, smooth muscles in the wall of the gastrointestinal tract perform these contractions. 
• Long reflexes, enteric nervous system, and gastrointestinal peptides control the movement of these muscles. 

Difference Between Peristalsis and Segmentation 

Definition 

Peristalsis refers to the involuntary contraction and relaxation of muscles of the intestine, creating wave-like movements, pushing the contents of the canal forward while segmentation refers to the back and forth smooth muscle contractions mainly in the small intestine for the smooth muscle contractions. 

Occurrence 

While peristalsis mainly occurs in the esophagus, segmentation mainly occurs in the small and large intestine.  

Types of Muscles 

Peristalsis occurs by the contractions of the circular muscles while segmentation occurs due to the rhythmic contractions of the longitudinal muscles.  

Type of Movement 

Moreover, peristalsis is a one-way motion in the caudal direction while segmentation is responsible for the movement in both directions, allowing a greater mixing.  

Speed of Propagation 

Peristalsis results in high-speed propagation of food while segmentation results in slow propagation of food. 

Conclusion 

Basically, peristalsis is a type of muscular contraction mainly occurs in the esophagus. Generally, the circular muscles of the esophagus produce one-way motion for the propulsion of food. On the other hand, segmentation is another type of muscular contraction mainly occurs in the small intestine. However, the longitudinal muscles in the small intestine produce back and forth movement of food. Furthermore, this allows the proper mixing of food with the secretions of the small intestine while facilitating mechanical digestion of food. Therefore, the main difference between peristalsis and segmentation is the type of motion they produce. 

References:

1. “155 23.2 Digestive System Processes and Regulation.” Anatomy and Physiology, OpenStax, 6 Mar. 2013, Available Here.

Image Courtesy:

1. “2404 PeristalsisN” By OpenStax College – Anatomy & Physiology, Connexions Web site. (CC BY 3.0) via Commons Wikimedia   
2. “2405 Digestive Process” By OpenStax College – Anatomy & Physiology, Connexions Web site. (CC BY 3.0) via Commons Wikimedia