The key difference between alimentary canal and digestive system is that alimentary canal, which is a part of the digestive system, is the long tubular canal running from mouth to anus while digestive system consists of both alimentary canal and other digestive glands.
Digestion is the principal process of acquiring nutrients and energy. The human digestive system consists of a long tubular canal in which the ingested food travels along. After the digestion of food, absorption, and assimilation take place. Finally, undigested foods excrete from the body by a process called egestion. The alimentary canal is a main part of the digestive system. In addition to the alimentary canal, the digestive system contains several accessory organs and glands. Hence this article discusses the difference between alimentary canal and digestive system.
CONTENTS
1. Overview and Key Difference
2. What is Alimentary Canal
3. What is Digestive System
4. Similarities Between Alimentary Canal and Digestive System
5. Side by Side Comparison – Alimentary Canal vs Digestive System in Tabular Form
6. Summary
What is Alimentary Canal?
The alimentary canal is a long tubular canal starting from the buccal cavity or the mouth and ending at the anus. The gastrointestinal canal is a synonym of the alimentary canal. It is a continuous tube that has a length of 7.62 meters. Smooth muscles form the alimentary canal. Therefore, it is involuntary in nature. Throughout the tube, there are other accessory organs such as the pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus.
Figure 01: Alimentary Canal
The alimentary canal opens to the exterior at the mouth and the anus. Also, many microorganisms reside on the alimentary canal. They are collectively called gut microbiota. They are very important in maintaining the homeostasis of the alimentary canal. The food moves through the alimentary canal by a constant rhythmic movement called the peristaltic movement. Furthermore, foods remain in the stomach for 2-3 hours before passing on to the intestines where the food absorption takes place. Finally, water absorption takes place at the large intestine, and the undigested food is released through the anus.
What is Digestive System?
The digestive system is a collective system comprising the alimentary canal and the other digestive glands and organs. Apart from the basic alimentary canal, organs such as the salivary glands, liver, gall bladder and the pancreas also a part of the digestive system and play a major role in it. They secrete various chemical compounds such as enzymes and hormones, which trigger the digestion process.
Figure 02: Digestive System
The salivary glands secrete saliva that facilitates the mechanical and chemical digestion in the oral cavity. The liver produces bile that enters the alimentary canal through the bile duct across the gall bladder and takes part in fat emulsification. The pancreas is another gland that secretes hormones and digestive enzymes to the alimentary canal through the pancreatic duct. It facilitates digestion in an alkaline environment.
Thus, with the help of the digestive glands and the alimentary canal forming the complete digestive system, digestion takes place efficiently in humans and other higher-order heterotrophs that follow the holozoic mode of nutrition.
What are the Similarities Between Alimentary Canal and Digestive System?
- Alimentary canal and digestive system help in facilitating the holozoic mode of nutrition that includes ingestion of food, digestion, absorption, assimilation, and egestion.
- Both systems function involuntarily.
- They consist of various secretions.
- Moreover, both systems are made up of smooth muscles that facilitate their respective functions.
- Gut microorganisms live in both systems.
What is the Difference Between Alimentary Canal and Digestive System?
The alimentary canal forms one part of the digestive system, and it is the long tubular canal that runs from mouth to anus. But, on the other hand, the digestive system is the complete organ system including the alimentary canal and other organs that carries out digestion in heterotrophs. So, this is the key difference between alimentary canal and digestive system.
Summary – Alimentary Canal vs Digestive System
The digestive system facilitates the digestion process in higher-order animals. It has two main components; alimentary canal and accessory organs and glands. The alimentary canal is a continuous tube through which accessory glands release secretions required for the digestion process. Both parts together function efficiently to facilitate digestion. Thus, this summarizes the difference between alimentary canal and digestive system.
Reference:
1. “ Overview of the Digestive System.” Anatomy and Physiology, OpenStax, 6 Mar. 2013, Available here.
Image Courtesy:
1. “Alimentary Canal (PSF)” By Pearson Scott Foresman – Archives of Pearson Scott Foresman, donated to the Wikimedia Foundation – extracted from another file: Alimentary Canal (PSF).jpg, (Public Domain) via Commons Wikimedia
2. “2401 Components of the Digestive System” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013 (CC BY 3.0) via Commons Wikimedia
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