Basics Of The Human Digestive System: Anatomy

The digestive is a complex composition of different organs working together to convert food to the energy and nutrients that the body needs to function. The food will flow through a long tube inside the body. This tube is known as the alimentary canal or also called the gastrointestinal tract (GI Tract). The alimentary canal starts at the oral cavity, and extends from the pharynx through the esophagus, stomach small intestines, to the large intestines. There are also several other accessory organs that help the body properly digest food, how ever food does not pass through these organs. Accessory organs that help the digestive system are your teeth, tongue, salivary glans, liver, gallbladder and pancreas TheDigestiveSystemse organs all work together to provide energy and nutrients to the body, There are six major  functions that happen within the bodies digestive system.

  1. Ingestion
  2. Secretion
  3. Mixing and movement
  4. Digestion
  5. Absorption
  6. Excretion

The Anatomy of the Digestive System

The Mouth

oral cavity crossFood digestion begins at the mouth, or  oral cavity. Inside the mouth, with the help of the accessory organ, such as the tongue, teeth and salivary glands, food is initially broken down. The teeth will begin to chop and break food down into smaller pieces as it is moistened by the salvia, before the tongue and other muscles push the food to the pharynx.

  • The teeth are 32 small, hard organs that developed along the lateral and anterior edges of the mouth. Eat tooth consist of bone-like matter called dentin and covered in a layer of enamel, which is the hardest substance that exist in the body. Teeth are living organs just like other parts of the body, they contain blood vessels that appears under the dentin and soft region inner region of the tooth, called pulp. Teeth are used for cutting and grinding food into smaller pieces
  • The tongue is a muscle located on the inferior portion of the most, just posterior and medial to the teeth. Its  small organ that is made up of different pairs of muscles that are covered in a thin, bumpy and skin layer. On the tongue are rough papillae, used for gripping food as it moves through the mouth. On the surface of the tongue are taste buds, that will detect taste molecules and connect to nerves that send taste signals to the bran. The  tongue pushes food to the  back/ posterior part of the mouth to be swallowed.
  • The Salivary Glands surround the mouth in 3 sets. These are accessory organs that produce a water-like secretion called saliva. Salvia is used to moisten food  and helps yo break down carbohydratesesophagus
    . The body uses saliva to lubricate food so that it can bases through the mouth, pharynx(throat) esophagus much easier.

The Pharynx or Throat

The pharynx is tube shaped as a funnel, that is connected to the posterior end of the mouth. THe masses  of chewed food passes through the pharynx to from the mouth to the esophagus. Within the respiratory system, the pharynx passes through air from the nasal cavity to the larynx and then the lungs. Since pharynx has two different functions, for the respiratory and digestive system, it uses the epiglottis, which is  flap that switches the rout of food to the esophagus and air to the larynx.

The Esophagus, is  muscular tube that connects the pharynx to the upper gastrointestinal tract of the stomach. This is were chewed food go along its length. At the inferior end of the esophagus is muscular ring called the esophageal sphincter, or cardiac sphincter that closes the end of the esophagus and trap the food inside the stomach.


The Stomach is rounded hallow muscular organ that is located on the left side of the abdominal cavity, which is inferior to the diaphragm. It is between the esophagus and the duodenum. The inner layer of the stomach is full of wrinkled rugae, known as gastric folds, which allow the stomach to stretch. The average person size stomach is the size of two fist next to each other.  The stomach organ acts as the storage container for food so that the body can properly digest it. If humans did not have the ststomachorage capacity of  the stomach, we would have to eat constantly instead of just a few times a day. The stomach has hydrochloric acid, mucus and digestive & sanitizing enzymes that continue the process from the mouth.

Small Intestine

The small intestine is a thin, 10 feet long, tube that is about an diameter of 1 inch, thats part of the lower gastrointestinal tract. It is twice the length of the larger intestine. The lower intestine in located inferior to the stomach and takes up much of the abdominal cavity. The entire mall intestine is coiled like a hose, which winds around other organs in the abdominal cavity. A small thin membrane called the mesentery extend form the posterior body wall to the abdominal cavity to keep the intestine in place. All the blood vessels, nerves and lymphatic vessels go through the mesentery The inside surface of the small intestine is full of many folds and ridges, these folds are used to maximize the digestion of food an absorb nutrients, By the time food leaves the small intestines, 90% of all the nutrients have been extracted.

The Liver and Gallbladder

The liver is located on the right of the stomach and inferior to the diaphragm and superior to the small intestine.  The liver is a  trianglar-shaped accessory organ. It weights about 3 pounds, and is the second largest organ in the body. Although the liver does many jobs in the body, handling: metabolism, immune system, storage of nutrients, it’s main duty to help digest food and produce  bile and secretion into the small intestine. The gallbladder is a small, pear-shaped organ that is posterior to the liver. It’s about 3 liverpaninches in length and 1.5 inches in width. It is used to recycle excess bile from the small intestine can can be used for later digestion of fatty foods in the duodenum of the small intestine.


The pancreas is a large gland that is inferior and posterior to the stomach, and about 6 inches long. Its shaped like a lumpy snake, It sets in the upper abdomen.  There are two glands in the pancreas: The first is a digestive exocrine gland and a hormone producing endocrine gland.  The second is the exocrine gland, which excretes enzymes to break done proteins lipids and carbohydrates in nucleic acids in food.

Large Intestine

The large intestine is about a 5 feet long, 2 1/2 inch thick in diameter, tube. It is located inferior to the stomach and winds around the superior and lateral border of the small intestine. Inside the intestinal wall is smooth muscle tissue that contracts and relaxes to move food and waste out of the body. The large intestine will absorb water, that has symbiotic bacteria, which breaks down waste and extract small amounts of nutrients. The intestine converts food into feces, it takes out vitamins produce by gut bacteria. The waste  in the large intestine exits through the anal canal.

Health Life Media Team

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