Digestive System

It depends on what you've eaten and if you've eaten a lot of carbohydrates, then that will take a while. but if you ate soup then that will take maximum half an hour and you'll definitely go to the bathroom. On the other hand if you've eaten Veggies , then that will take maximum 1 hour, and if you've eaten Meat then that will take approx. 1 hour and a half.

It will take almost 7 hours to digest a chewing gum!!!! If you swallow it. of course !!

Before answering this question you should be aware of the meaning of food and different types of food.

The body needs Proteins, Carbohydrates and fat in order to grow. But this can not function without the breaking of food i.e Digestion. Digestion helps the food to be broken down into simple particles so that can enter the body through the flow of blood.

In mammals, food enters the mouth, being chewed by teeth, with chemical processing beginning with chemicals in the saliva from the salivary glands. Then it travels down the esophagus into the stomach, where acid both kills most contaminating microorganisms and begins mechanical break down of some food (e.g., denaturation of protein), and chemical alteration of some. After some time (typically an hour or two in humans, 4-6 hours in dogs, somewhat shorter duration in house cats, ...), the results go through the small intestine, through the large intestine, and are excreted during defecation.

Upper and Lower human gastrointestinal tract

The whole digestive system is around 9 meters long. In a healthy human adult this process can take between 24 and 72 hours.

• Cephalic phase - This phase occurs before food enters the stomach and involves preparation of the body for eating and digestion. Sight and thought stimulate the cerebral cortex. Taste and smell stimulus is sent to the hypothalamus and medulla oblongata. After this it is routed through the vagus nerve and release of acetylcholine. Gastric secretion at this phase rises to 40% of maximum rate. Acidity in the stomach is not buffered by food at this point and thus acts to inhibit parietal (secretes acid) and G cell (secretes gastrin) activity via D cell secretion of somatostatin.
• Gastric phase - This phase takes 3 to 4 hours. It is stimulated by distention of the stomach, presence of food in stomach and decrease in pH. Distention activates long and myentric reflexes. This activates the release of acetylcholine which stimulates the release of more gastric juices. As protein enters the stomach, it binds to hydrogen ions, which lowers the pH of the stomach to around pH 1-3. Inhibition of gastrin and HCl secretion is lifted. This triggers G cells to release gastrin, which in turn stimulates parietal cells to secrete HCl. HCl release is also triggered by acetylcholine and histamine.
• Intestinal phase - This phase has 2 parts, the excitatory and the inhibitory. Partially-digested food fills the duodenum. This triggers intestinal gastrin to be released. Enterogastric reflex inhibits vagal nuclei, activating sympathetic fibers causing the pyloric sphincter to tighten to prevent more food from entering, and inhibits local reflexes.

There fore; All kinds of food must be digested.

Consider for a moment a Big Mac. The purpose in your eating a Big Mac, other than simple hedonism, is to assimilate the nutrients it represents and make them available to build, repair and maintain your own tissues, as well as provide energy for studying and occasional other pursuits.

You may have asked yourself - "Exactly what nutients are present in a Big Mac that I can assimilate?" MacDonald's comes close to full disclosure in this regard, but what they don't tell you is that in order to take advantage of these nutrients, you have to provide the means to carefully break them down into much smaller molecules that can be imported into blood. Luckily, your digestive system takes care of this very complex process so efficiently that most of the time you don't even need to think about it.

At its simplest, the digestive system it is a tube running from mouth to anus. This tube is like an assembly line, or more properly, a dissembly line. Its chief goal is to break down huge macromolecules (proteins, fats and starch), which cannot be absorbed intact, into smaller molecules (amino acids, fatty acids and glucose) that can be absorbed across the wall of the tube, and into the circulatory system for dissemination around your body.

The breakdown of foodstuffs like a Big Mac is accomplished through a combination of mechanical and enzymatic processes. To accomplish this breakdown, the digestive tube requires considerable assistance from accessory digestive organs such as the salivary glands, liver and pancreas, which dump their secretions into the tube. The name "accessory" should not be taken to mean dispensible; indeed, without pancreatic enzymes you would starve to death in short order.

In many ways, the digestive system can be thought of as a well-run factory in which a large number of complex tasks are performed. The three fundamental processes that take place are:

• Secretion: Delivery of enzymes, mucus, ions and the like into the lumen, and hormones into blood.
• Absorption: Transport of water, ions and nutrients from the lumen, across the epithelium and into blood.
• Motility: Contractions of smooth muscle in the wall of the tube that crush, mix and propel its contents.

Each part of the digestive tube performs at least some of these tasks, and different regions of the tube have unique and important specializations.

Like any well-run factory, proper function of the digestive system requires robust control systems. Control systems must facilitate communication among different sections of the digestive tract (i.e. control on the factory floor), and between the digestive tract and the brain (i.e. between workers and managment).

Control of digestive function is achieved through a combination of electrical and hormonal messages which originate either within the digestive system's own nervous and endocrine systems, as well as from the central nervous sytem and from endocrine organs such as the adrenal gland. Different parts of these systems are constantly talking to one another. The basic messages are along the lines of "I just received an extraordinary load of food, so I suggest you get prepared" (stomach to large intestine) or "For goodness sake, please slow down until I can catch up with what you've already given me" (small intestine to stomach).

Finally, a note about differences in digestive anatomy and physiology among animals. The digestive systems of humans, dogs, mice, horses, kangaroos and great white sharks are, to a first approximation, virtually identical. If you look more carefully however, it becomes apparent that each of these species has evolved certain digestive specializations that have allowed it to adapt to a particular diet.

These differences become particularly apparent when you compare a carnivore like a cat with a herbivore like a goat or a horse. Goats and horses evolved from ancestors that subsisted on plants and adapted parts of their digestive tracts into massive fermentation vats which enabled them efficiently utilize cellulose, the major carbohydrate of plants.

In contrast, cats evolved from animals that lived on the carcasses of other animals, and have digestive systems that reflect this history - extremely small fermentation vats and essentially no ability to utilize cellulose. Bridging the gap between carnivores and herbivores are omnivores like humans and pigs, whose digestive tracts attest to a historical diet that included both plants and animals. The image above shows a young omnivore in the company of herbivore and carnivore friends.