Key Difference – Peristalsis vs Segmentation
Peristalsis and segmentation are two types of the smooth muscle movements of the GI tract. Peristalsis pushes the food downward in one direction while segmentation does not cause for net movement of food inside the GI tract. This is the key difference between peristalsis and segmentation.
Digestion and absorption are regulated by the different types of muscular movements of the gastrointestinal system. Ingested food is broken down into small components and is propelled through the GI tract and maximized the absorption in the intestine. Peristalsis and segmentation are two types of intestinal movements or the smooth muscle movements of the GI tract. Peristalsis is the alternate contractions and relaxations of circular and longitudinal muscles in the GI tract that propels foods into the downward direction from the mouth through the GI tract. Segmentation is the contraction of circular muscles of the small and large intestine that mixes chyme with gastric secretions and breaks chyme into small pieces.
CONTENTS
1. Overview and Key Difference
2. What is Peristalsis
3. What is Segmentation
4. Similarities Between Peristalsis and Segmentation
5. Side by Side Comparison – Peristalsis vs Segmentation in Tabular Form
6. Summary
What is Peristalsis?
Peristalsis is the alternate contraction and relaxation of smooth muscles in the GI tracts in a wave-like manner that propels food bolus downward from the mouth through the GI tract. Contraction and relaxation of muscles happen continuously in one direction.
Figure 01: Peristalsis
Peristalsis predominately occurs in the oesophagus, and it occurs throughout the GI tract. Food movement occurs in one direction during peristalsis and hence, mixing of the food with other secretions is low.
What is Segmentation?
Segmentation is a type of muscular movement of the GI tract that helps chyme to mix with gastric secretions and breaks into small parts for easy digestion. Segmentation occurs when the circular muscles of the GI tract contracts. It predominately occurs in the small intestine and large intestine.
Figure 02: Segmentation
Segmentation does not show the net movement of food in one direction. Instead, it mixes chyme with gastric secretions for the purpose of digestion and absorption.
What are the Similarities Between Peristalsis and Segmentation?
- Both Peristalsis and Segmentation are movements of food along the gastrointestinal tract.
- Both Peristalsis and Segmentation help break up, mix and move food along the GI tract.
- Both Peristalsis and Segmentation may be triggered by pacemaker cells, hormones, chemicals, and physical stimulation.
- A number of hormonal and nervous factors initiate and maintain peristalsis and segmentation.
What is the Difference Between Peristalsis and Segmentation?
Peristalsis vs Segmentation |
|
| The wave-like rhythmic muscular contractions of the GI tract that propel food downward is known as peristalsis. | Segmentation is a muscular type movement of the intestine. |
| Part of the GI tract It Predominates | |
| Peristalsis predominates in the oesophagus. | Segmentation predominates in large intestine and small intestine. |
| Direction | |
| Peristalsis involves pushing bolus in a downward direction (one-way motion). | Segmentation moves chyme in both directions. |
| Muscle Contraction | |
| Peristalsis involves rhythmic contractions of the longitudinal muscles in the gastrointestinal tract. | Segmentation involves contractions of the circular muscles in the digestive tract. |
| Action | |
| Peristalsis is also known as propulsive contractions. | Segmentation is also known as mixing contractions. |
| Muscles Involved | |
| Both circular and longitudinal muscles are involved with peristalsis. | Circular muscles are involved with segmentation. |
| Occurrence | |
| Peristalsis occurs in whole GI tract. | Segmentation occurs in small intestine and large intestine. |
| Speed | |
| Peristalsis shows the comparatively high progression of the bolus through the oesophagus. | Segmentation shows slow progression of chyme through the system. |
| Direction of Food | |
| Peristalsis pushes foods downwards. | Segmentation does not produce a net movement of foods in any particular direction. |
| Thorough Mixing | |
| Some mixing occurs during peristalsis. | Thorough mixing of chyme with secretions occurs during segmentation. |
| Breaking of Food | |
| Compared to segmentation, breaking food into small pieces is low by peristalsis. | Segmentation helps break chyme into small pieces. |
Summary – Peristalsis vs Segmentation
Peristalsis and segmentation are two muscular actions of GI tract during digestion. Peristalsis is responsible for the downward direction of foods through the GI tract while segmentation is responsible for the proper mixing of the foods with gastric secretions and breaking of foods into small pieces for easy digestion. Peristalsis occurs when the circular and longitudinal muscles of the GI tract contract and relax with an alternate manner. Segmentation occurs when the circular muscle contracts in front and backward directions. This is the difference between peristalsis and segmentation.
Reference:
1. “Segmentation.” Digestive System. Available here
2.“Segmentation Contractions.” Wikipedia, Wikimedia Foundation, 3 Apr. 2018. Available here
Image Courtesy:
1.’Peristalsis’By Boumphreyfr – Own work, (CC BY-SA 3.0) via Commons Wikimedia
2.’2419 Segmentation’By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013., (CC BY 3.0) via Commons Wikimedia