Digestive Systems And The Digestive System - amazonia.fiocruz.br

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The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion the tongue , salivary glands , pancreas , liver , and gallbladder. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase , the gastric phase , and the intestinal phase. The first stage, the cephalic phase of digestion, begins with gastric secretions in response to the sight and smell of food. This stage includes the mechanical breakdown of food by chewing , and the chemical breakdown by digestive enzymes, that takes place in the mouth. Saliva contains digestive enzymes called amylase , and lingual lipase , secreted by the salivary glands and serous glands on the tongue. The enzymes start to break down the food in the mouth. Chewing, in which the food is mixed with saliva, begins the mechanical process of digestion.

Digestive Systems And The Digestive System Video

Digestion in Human Beings 3D CBSE Class 7 Science (amazonia.fiocruz.br)

Digestive Systems And The Digestive System - something also

Directions: Print out Week 6 worksheet. Fill it out electronically and return it to instructor via email by the end of the class period. Main Function:. Food provides us with fuel to live, energy to work and play, and the raw materials to build new cells. All the different varieties of food we eat are broken down by our digestive system and transported to every part of our body by our circulatory system. Digestive Systems And The Digestive System

The function of the digestive system is to break down the foods you eat, release their nutrients, and absorb those nutrients into the body.

Although the small intestine is the workhorse of the system, where the majority of digestion occurs, and where most of the released nutrients are absorbed into the blood or lymph, each of the digestive system Digestibe makes a vital contribution to this process Figure As is the case with all body systems, the digestive system does not work in isolation; it functions cooperatively with the other systems of the body. Consider for example, the interrelationship between the digestive and cardiovascular systems.

Arteries supply the digestive organs with oxygen and processed nutrients, and veins drain the digestive tract. These intestinal veins, constituting the hepatic portal system, are unique; they do not return blood directly to the heart. Rather, this blood is diverted to the liver where its nutrients are off-loaded for Syxtems before blood completes its circuit back to the heart. At the same time, the digestive system provides nutrients to the heart muscle and vascular tissue to support their functioning.

The interrelationship of the digestive and endocrine systems is also critical. Hormones secreted by several endocrine glands, as well as endocrine cells of the pancreas, the stomach, and the small intestine, contribute to the control of digestion and nutrient metabolism. In turn, the digestive system provides the nutrients Andd fuel endocrine function.

Table The easiest way to understand the digestive system is to divide its organs into two main categories. The first group is the organs that make up the alimentary canal. Accessory digestive organs comprise the second group click are critical for orchestrating the breakdown of food and the assimilation of its nutrients into the body. Accessory digestive organs, despite Digeestive name, are critical to the function of the digestive system. The main function of the organs of the alimentary canal is to nourish the body. This tube begins at the mouth and terminates at the anus.

Between those two points, the canal is modified as the pharynx, esophagus, stomach, and small and large intestines to fit the functional needs of the body. Both the mouth and anus are open to the external environment; thus, food and wastes within the alimentary canal are technically considered to be outside the body. Each accessory digestive organ aids in the breakdown of food Figure Within the mouth, the teeth Digesstive tongue begin mechanical digestion, whereas the salivary glands begin chemical digestion. Once food products enter the small intestine, the gallbladder, liver, and pancreas release secretions—such as bile and enzymes—essential for digestion to continue.

Together, these are called accessory organs because they sprout from the lining cells of the developing gut mucosa and augment its function; indeed, you could not live without their vital contributions, and Digestive Systems And The Digestive System significant diseases result from their malfunction.

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Even after development is complete, they maintain a connection to the gut by way of ducts. Throughout its length, the alimentary tract is composed of the same four tissue layers; the details of their structural arrangements vary to fit their specific functions. Starting from the lumen and moving outwards, these layers are the mucosa, submucosa, muscularis, and serosa, which is source with the mesentery see Figure ]