This is a magnified picture of the inside of the mouth (under the tongue), where the digestive system begins.
The course from when you take your first bite of food to when the indigestible parts are excreted is a lengthy one. The ingested food must take a 20-30 feet route to reach its destination, which ranges from twenty-four to seventy-two hours total. To put this in perspective, this journey takes longer than flying around the whole world. Rather than a plane, though, the food's means of transportation is the digestive system (also known as the gastrointestinal system or alimentary canal). When you travel around the world you visit many different countries, similarly when the food travels through the digestive system it "visits" various parts of the body. These parts include the oral cavity (mouth), esophagus, stomach, small intestine, and large intestine. The accessory organs, such as the liver, pancreas, and gall bladder, are also essential parts of the journey, however the food doesn't actually pass through these organs. The accessory organs could be compared to the maintenance crew or radio control people, who make the flight around the world possible. The digestive system is a vital component of the human body, because it is necessary for life function, homeostasis, and it also works interdependently with other body systems.
The digestive system involves ingesting food and using mechanical and chemical methods to break down the food into nutrient molecules that can be absorbed into the bloodstream. This life function is known as nutrition. Nutrition is the obtaining and processing of materials needed for energy, growth, repair, and regulation. Some examples of nutrients needed by the body are proteins, carbohydrates, water, fats, vitamins, and minerals. The digestive system makes it possible for these nutrients to be consumed by the cells in the human body, but to do so the digestive system must work closely with the circulatory system. The food is macerated by the digestive system and the absorbed nutrients are then carried throughout the body to the cells by the circulatory system. Chemical signals from the endocrine system, which control the speed of digestion, are also transported by the Circulatory system. The nervous system also has an essential relationship with the digestive system. The nervous system's ANS (involuntary nervous system) controls movement, secretion, passage of materials along the tract, and skeletal muscles which regulate ingestion. In return the digestive system provides substrates critical for neurotransmitter synthesis.
The digestive system is also important in helping to maintain homeostasis in humans. As we use up energy, we are using up nutrients, substances that provide the body with the materials and energy needed to carry out all life functions, so in order to keep a balance we must take in more nutrients. The digestive system allows us to do this by breaking down food, which supplies the blood with nutrients and then the blood distributes them to the rest of the body. This once again demonstrates the critical interaction between it and the circulatory system. The digestion of water is also important in preserving homeostasis because water helps sustain body temperature and almost all chemical reactions take place in water. Without it the human body would not be able to keep equilibrium. The liver also plays a role in maintaining homeostasis. The liver stores excess glucose as glycogen and then secretes it when the body has a low balance of glucose.
The digestive system involves ingesting food and using mechanical and chemical methods to break down the food into nutrient molecules that can be absorbed into the bloodstream. This life function is known as nutrition. Nutrition is the obtaining and processing of materials needed for energy, growth, repair, and regulation. Some examples of nutrients needed by the body are proteins, carbohydrates, water, fats, vitamins, and minerals. The digestive system makes it possible for these nutrients to be consumed by the cells in the human body, but to do so the digestive system must work closely with the circulatory system. The food is macerated by the digestive system and the absorbed nutrients are then carried throughout the body to the cells by the circulatory system. Chemical signals from the endocrine system, which control the speed of digestion, are also transported by the Circulatory system. The nervous system also has an essential relationship with the digestive system. The nervous system's ANS (involuntary nervous system) controls movement, secretion, passage of materials along the tract, and skeletal muscles which regulate ingestion. In return the digestive system provides substrates critical for neurotransmitter synthesis.
The digestive system is also important in helping to maintain homeostasis in humans. As we use up energy, we are using up nutrients, substances that provide the body with the materials and energy needed to carry out all life functions, so in order to keep a balance we must take in more nutrients. The digestive system allows us to do this by breaking down food, which supplies the blood with nutrients and then the blood distributes them to the rest of the body. This once again demonstrates the critical interaction between it and the circulatory system. The digestion of water is also important in preserving homeostasis because water helps sustain body temperature and almost all chemical reactions take place in water. Without it the human body would not be able to keep equilibrium. The liver also plays a role in maintaining homeostasis. The liver stores excess glucose as glycogen and then secretes it when the body has a low balance of glucose.