Learn About The Digestive System

Simply put, the digestive system is a portal for nutrients from the environment to gain access to the circulatory system.
Before such transfer can occur, foodstuffs first have to be reduced to very simple molecules by a combination of mechanical and enzymatic degradation. The resulting sugars, amino acids, fatty acids and the like are then transported across the epithelium lining the intestine into bloo

Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones.

In mammals, food enters the mouth, being chewed by teeth, with chemical processing beginning with chemicals in the saliva from the salivary glands. This is called mastication. Then it travels down the esophagus into the stomach, where hydrochloric acid kills most contaminating microorganisms and begins mechanical break down of some food (e.g., denaturation of protein), and chemical alteration of some. The hydrochloric acid also has a low pH, which allows enzymes to work more efficiently. After some time (typically an hour or two in humans, 4?6 hours in dogs, somewhat shorter duration in house cats, ...), the resulting thick liquid is called chyme. Chyme will go through the small intestine, where 95% of absorption of nutrients occurs, through the large intestine, and are eliminated during defecation.

Other organisms use different Category: wikt - :mechanism|mechanisms to digest food.

The esophagus (or oesophagus; see spelling differences), sometimes known as the gullet, is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach. The word esophagus is derived from the Latin ?sophagus, which derives from the Greek word oisophagos , lit. "entrance for eating." In humans the esophagus is continuous with the laryngeal part of the pharynx at the level of the C6 vertebra. The esophagus passes through posterior mediastinum in thorax and enters abdomen through a hole in the diaphragm at the level of the tenth thoracic vertebrae (T10). It is usually about 25?30 cm long and connects the mouth to the stomach. It is divided into cervical, thoracic and abdominal parts. Due to the inferior pharyngeal constrictor muscle, the entry to the esophagus opens only when swallowing or vomiting.

After the food has been swallowed, it's carried down the oesophagus (a muscular tube) towards the stomach. The oesophagus can contract and relax in order to propel the food onwards, and each mouthful of food takes about six seconds to reach the stomach once swallowed.

The mouth is the first portion of the alimentary canal that receives food and

saliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth.

In addition to its primary role as the beginning of the digestive system, in humans the mouth also plays a significant role in communication. While primary aspects of the voice are produced in the throat, the tongue, lips, and jaw are also needed to produce the range of sounds included in human language. Another non-digestive function of the mouth is its role in secondary social and/or sexual activity, such as kissing.

The mouth is normally moist, and is lined with a mucous membrane. The lips mark the transition from mucous membrane to skin, which covers most of the body.

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When you drink plenty of water, your digestive system is able to run much more smoothly. Many health problems can be at least partially traced to your digestive tract, and the easiest, best way to increase your digestive health is to drink plenty of pure water

The stomach is a sack made of muscle and, when it's empty, it has a volume of only 50ml but this can expand to hold up to 1.5 litres or more after a meal. The walls of the stomach are made of three different layers of muscle that allow it to churn food around and make sure it's mixed with the stomach's acidic digestive juices. The presence of hydrochloric acid in the stomach prevents the action of salivary amylase and helps to kill bacteria that might be present. The stomach also produces the enzyme pepsin, which breaks down proteins

In some animals, including vertebrates, echinoderms, insects (mid-gut) and molluscs, the stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract. It is involved in the second phase of digestion, following mastication (chewing). The stomach is located between the oesophagus and the small intestine. It secretes protein-digesting enzymes and strong acids to aid in food digestion, (sent to it via oesophageal peristalsis) through smooth muscular contortions (called segmentation) before sending partially-digested food (chyme) to the small intestines.

The word stomach is derived from the Latin stomachus which is derived from the Greek word stomachos, ultimately from stoma (), "mouth". The words gastro- and gastric (meaning related to the stomach) are both derived from the Greek word gaster ().

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