What is the digestive system
Digestive system includes the digestive tract and accessory devices, which process food into molecules that can be absorbed and used by the body's cells.
Food is broken down slowly until particles are small enough to be absorbed and disposed of waste products.
it is also called gastrointestinal tract and digestive system. It consists of a long continuous tube that runs from the mouth to the anus. And includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Tongue and teeth are accessory structures located in the mouth. Salivary glands, liver, gallbladder and pancreas are not part of the digestive tract, but is a major accessory organs in the digestive system, which plays a role in the process of digestion. These fluids excreted in the digestive tract.
Function of Digestive tract
Food is subject to three types of processes in the body:DigestionAbsorptionMetabolism
Digestion and absorption occur in the digestive tract. After nutrients are absorbed, they are available to all cells in the body, and is used by these cells in the process of metabolism. Metabolism is the sum of all chemical reactions that occur in the body, including the utilization of nutrients.
Gastroenterology is the nutrients for use by the body's cells through six activities
Swallow - the first activity of the digestive system is to take in food. This needs to be done before anything else can happen.
Mechanical digestion and a wide range of food must be broken down into smaller so that it can start various enzymes activity in a series of events. Mechanical digestion begins in the mouth with chewing or mastication of food and continues with churning and mixing procedures within the stomach.
Chemical digestion digestion by chemical molecules in smaller molecules can be easily absorbed and utilized by the cells.
Movements after eating, chewing, and the transfer of food particles from the mouth into the stomach, then into the esophagus. This movement is swallowing or swallowing. And called on the movements that push food particles through the digestive tract peristalsis. These are the waves of rhythmic contractions that move food particles through the various regions in the process of digestion by mechanical and chemical takes place.
The absorption of simple molecules that result from the passage of chemical digestion through the cell membrane of the lining of the small intestine into the blood in the capillaries or lymph. This process is called absorption.Elimination - food particles that can not be digested need to get rid of the body. The so-called indigestible waste removal through the anus, in the form of the stool, defecation.
Structure of Digestive system
long continuous tube digestive about 9 meters in length. It opens to the outside at both ends, by mouth at one end, and through the anus at the other end. Although differences there in each region, and the infrastructure of the wall is the same throughout the length of the tube.
The wall of the digestive tract has four layers:
Mucosa or mucous membrane layer, is the most profound of the wall. It cavity channel lines. In certain areas secrete mucus mucosa, digestive enzymes, and hormones. Channels of other glands pass through the mucous membrane of the cavity. In the mouth and anus are needed thickness of the mucosa of the likelihood of corrosion protection, while the stomach and intestines and have a thin layer to allow the secretion and absorption.
Submucosal, is a thick layer of loose connective tissue that surrounds the mucosa. This layer also contains blood vessels and lymph, nerves and some glands. Blood vessels supplying food to the surrounding tissue. Blood and lymph carry food away absorbed which are the final products of the digestion process.
Muscularis , which consists of two layers of smooth muscle. When two layers of muscle tissue decade, and reduced the diameter of the pipe. This is called muscle contraction layer peristalsis.
Serous layer or serum is. External cladding of the digestive tube and is also called serum from the digestive tract of visceral peritioneum. It secretes serous fluid for lubrication so that the abdominal organs to move smoothly against each other to prevent friction. And anchor loops of the digestive tract from the back wall of the abdominal cavity through a large double fold of tissue called peritoneal mesentary.
Regions of Digestive tract
Mouth: Oral cavity or mouth is the first part of the digestive tract. And adapted to receive food by ingestion. The food will be divided into small particles of chewing and mixed with saliva. Lips, cheeks, palate constitute the border. Oral cavity contains the teeth and tongue, and receives from the secretions of the salivary glands.
Lips, cheeks, helps to hold the food in the mouth and keep them in place for chewing or chewing. They are also used in the composition of words for languages. Reddish color lips due to the transparent tissue lying just above the blood vessels in many lips. This is why we lips can be used as a test for symptoms of blue or blue dye from the tissue due to lack of oxygen. Lips also nerve endings that will help us to determine the temperature and texture of foods.
Palate is the roof of the mouth cavity. It separates the oral cavity from the nasal cavity. And called the front part of the hard palate and it is supported by the bone. Monitors the back or the soft palate consists of connective tissue and skeletal muscle tissue. Posteriroly, and hard palate ends in a projection called the uvula. During swallowing, the soft palate and uward step ubula to direct food away from the nasal cavity and pharynx. Cleft palate is a condition in which the bones in the hard palate is not completely fuse together during prenatal growth. This leaves a hole between the sinuses and mouth. Baby with this difficult problem in finding enough proper nutrition intake. Cleft palate can usually be corrected with a series of surgeries and dental work with the child develops.
tongue is the largest and most transmitted in the oral cavity. More of a substance is made tongue and skeletal muscles. Main facility of the tongue is the root or the rear area, which is based on the hyoid bone. Remember that of the skeletal system? The front part is relatively free, but this is linked to the floor of the mouth of the bridle. Cover the surface of the tongue called papillae with expectations. In addition to providing friction food processing contain papillae taste buds. Masses of lymphoid tissue providing defense against bacteria as it enters the mouth, called these languages tonsils. Muscles of the tongue to allow for manipulation of food to form a ball or bolus to make it easy to swallow. The person who is called to bridle my tongue a short tongue-tied. The only abnormally in the movement of the tongue, which causes difficulty in speech. Cut surgically bridle corrects this problem.
Teeth: Two different sets of teeth put teeth in the mouth. The first group usually begin to appear at the age of 6 months and continues to develop until about the age of 3. This group is called the primary teeth or deciduous (baby teeth). There are about 20 in all. Permanent teeth or secondary usually begin to appear at the age of 6-7 years of age. This set contains a total of 32 teeth. And third molar teeth post explosion. Sometimes called "wisdom teeth" and begin to erupt between the ages of 17 - 25. These teeth may remain an integral part of the jaw bone. In some cases, the wisdom teeth are all absent. Different shaped teeth to deal with the food in different ways. Cutters are engraved and have sharp edges Food biting; fangs or acnines are cone-shaped and have a point to absorb and tearing food; bicuspids (premolars) and molars have flat surfaces with rounded projections for crushing and grinding. Although different types of teeth have different forms and functions, each age of three distinct parts: the crown, neck, and root. The crown is the visible part of the tooth covered by enamel. Root is the part embedded in the sockets of the mandible and maxilla. The neck is small region crown and root meet next gums or gums. The central core of the tooth is the pulp cavity, which consists of connective tissue, blood vessels, and nerves. And takes the pulp cavity of ivory, which constitutes the bulk of the tooth. Ivory surrounded by a thin layer of connective tissue called cementum calcified root attached to the laces. Tooth enamel, the hardest substance in the body, surrounded Ivory in the crown of the tooth. Decay is the medical term for the cavity.
Salivary glands are there, three pairs of salivary glands large and numerous small ones that secrete saliva in the oral cavity, where it is mixed with the food during chewing. Parotid glands are the largest of the salivary glands. Located submandibular glands on the floor of the mouth. Sublingual glands are in the floor of the mouth. Mumps is a viral disease that affects the parotid glands. Infection causes inflammation of the gland, which makes opening the mouth and chewing difficult. If the disease occurs in adolescent males, the infection may spread to the testicles, which in severe cases, may lead to infertility.
Saliva contains water, mucus, and amylase enzyme. And saliva following functions:
Cleansing action on the teeth
Wet and lubricates the food
Dissolves certain food particles so that they can actually taste the food
Begin the process of chemical digestion of carbohydrates through the action of amylase
Pharynx, is a corridor connecting the sinuses and mouth. It leads to the larynx, esophagus and act as a conduit for both system respiratory and digestive system. (Air, food), which contains the tonsils or adenoids in the throat and is often called. The pharynx is divided into three sections: the nasopharynx, pharynx, laryngopharnyx. Food is imposed in the throat by the tongue. When the food is up to the opening, initiate involuntary reflex swallowing. The soft palate is elevated to prevent food from entering the nasopharynx. Epiglottis decline downward to prevent food from entering the larynx and directing food into the esophagus.
Esophagus is a tube - folding muscle, about 25 centimeters which serves as a passageway between the pharynx and stomach. As it travels from the front landing to the spine and back into the trachea. Called passes through a hole in the diaphragm, and watching the esophagus, and it hurt in the stomach. There the lower esophageal sphincter and the Supreme, and so-called low sphincter muscle heart because of its location.
Stomach receives food from the esophagus and is located in the left upper quadrant of the abdomen. It's the ability varies, but in an average adult it holds 1.5 liters Although some individuals may hold up to 4 liters. The stomach is divided into four regions:
Cardiac region small area around the opening of the esophagus.
The bottom of the region due to the shape of the stomach is the most superior region, it balloons over the area of the heart to the formation of an interim storage area
The body is the main part of the stomach
Pyloric region which acts as a valve between the stomach and the small intestine
When the stomach is empty there are folds in the lining of the stomach called the meantime.
Meanwhile allow for expansion and flexibility muscle folds eat.