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:
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.
The liver, Pancreas, Gallbladder, stomach, and small and large intestines all do a different part in digesting the food.
Each part of the factory has it's own ability and job.
Because the food is being carried down a tube (convayer belt) and the body is taking all the neutriance it needs while it travels down.
It takes food apart into its components.
They both eat nig@@s
sike
it is different cause they are smaller
The digestive system is a large system and takes up space from the mouth to the pelvis. Different parts of the digestive system are located in different regions of the body.
Many different structures are needed by the digestive system to function different parts of the digestive system.
my mom
the urinary system
The digestive system is a large system and takes up space from the mouth to the pelvis. Different parts of the digestive system are located in different regions of the body.
Digestive system
the urinary system
Tigers are carnivores and deer are vegetarians - their digestive systems have to be different in structure and function because of different diets.
well the circulatory system is different to the digestive system because its responsible to pass nutrients and to transport blood,deals with heart arteries,veins,which the digestive system is responsible to provide energy for the heart to pump blood.
The digestive system is different from the other human body systems because the digestive system holds food and no other human body system does also the digestive system has organs that none other human body systems have.
my mom