The Human Digestive System

The Human Digestive System
DEFINITIONS
Digestive system (from mouth to anus) function as follows: - Receive food - Break down food into nutrients (a process called digestion) - Absorb nutrients into the bloodstream - Discard the food that can not be digested from the body.
Alimentary canal consists of mouth, throat, esophagus, stomach, small intestine, colon, rectum and anus. Digestive system also includes the organs that are located outside of the digestive tract, ie pancreas, liver and gallbladder.
Alimentary canal
Mouth, Throat & throat
The mouth is the entrance to the digestive system and respiratory system. Part dalamdari mouth covered by a mucous membrane.
Tract from salivary glands in the cheeks, under the tongue and under the jaw drain its contents into the mouth. On the floor of the mouth there are tongues, yangberfungsi to taste and mix food.
Behind and below the mouth there are throat (pharynx).
Taste felt by sensitive organs located on the surface of the tongue. Smell is felt by the olfactory nerve in the nose. Taste is relatively simple, consisting of sweet, sour, salty and bitter. Smell is more complicated, consisting of a variety of odors.
Food is cut into pieces by the front teeth (incisive) and chewed by the back teeth (molars, molars), into smaller parts more easily digested. Saliva from the salivary glands going to wrap the parts of the food with digestive enzymes and begin digesting it.
At mealtimes, the flow of saliva to clean the bacteria that can cause tooth decay and other disorders. Saliva also contains antibodies and enzymes (eg lysozyme), which breaks down protein and attack the bacteria directly.
The process of swallowing begins to consciously and continues automatically. Epiglotis will be closed so that food does not get into the air pipe (trachea) and into the lungs, whereas the rear part of the roof of the mouth (palate mole, soft palate) raised so food does not enter into the nose.
Gullet (esophagus) is a muscular channel thin-walled and lined by mucous membrane. Esophagus connects the throat with the stomach. Food through the esophagus is not driven by gravity, but by the waves of rhythmic contraction and relaxation of muscles is called peristalsis.

Hull is a hollow muscular organ shaped like a cage big and donkeys, consists of three parts, namely the cardia, fundus and antrum.
Food into the stomach from the esophagus through a ring-shaped muscle (sphincter), which can open and close. Under normal circumstances, re-entry of sphincter prevents stomach contents into the esophagus.
Gastric functions as a food warehouse, which is rhythmic contractions to mix food with enzymes. The cells lining the stomach produce three important substances: - Mucus - Hydrochloric acid - Precursor of pepsin (enzymes that break the protein). The mucus protects the stomach cells from damage by stomach acid and enzymes. Any defects in this mucus layer (whether due to infection by the bacterium Helicobacter pylori or aspirin), can cause damage that leads to the formation of ulcers.
Hydrochloric acid creates an atmosphere that is very acidic, which is required by pepsin to break down proteins. High gastric acidity also acts as a barrier against infection by killing the bacteria. Disposal of acid is stimulated by: - The nerve that leads to the stomach - Gastrin (a hormone released by the stomach) - Histamine (a substance that is released by the stomach).
Pepsin is responsible for approximately 10% protein solution. Pepsin is the only enzyme that digests collagen, which is a protein and the main content of the meat.
Only a few substances that can be directly absorbed from the stomach (such as alcohol and aspirin) and that too only in very small quantities.
Gastric Parts
Small intestine
Gastric release of food into duodenum (duodenum), which is the first part of the small intestine. Food into the duodenum through the pyloric sphincter in the amount that can be digested by the intestine. If it is full, the duodenum to the stomach sends a signal to stop flow of food.
The duodenum receives pancreatic enzymes from the pancreas and bile from the liver. Fluid (which enter into the duodenum through a hole called the sphincter Oddi) is an important part of the process of digestion and absorption. Peristaltic movement also helps digestion and absorption by stirring and mixing it with substances produced by the intestine.
The first few inches of the duodenum is a slippery coating, but the remainder have folds, small bumps (villi) and a smaller bulge (microvilli). Villi and microvilli increase the surface of the layer causing the duodenum, thereby increasing the amount of nutrients absorbed.
The rest of the small intestine, located below the duodenum, jejunum and ileum consists of. This section is primarily responsible for the absorption of fat and other nutrients. This absorption is magnified by the surface area because of folds, villi and microvilli.
Intestinal wall is rich in blood vessels that carry substances that are absorbed into the liver through the portal vein. Intestinal wall to release mucus (which lubricate the gut content) and water (which helps dissolve the fragments of the digested food). Intestinal wall is also releasing a small amount of enzyme that digests protein, sugar and fat.
Density of intestinal contents change gradually, in line with its journey through the small intestine. In the duodenum, the water quickly pumped into the intestine to dissolve the contents of gastric acidity. When I passed the bottom of the small intestine, intestinal contents become more fluid because it contains water, mucus and pancreatic enzymes.
Anatomy of the Stomach and small intestine contents
Pancreas
Pancreas is an organ which consists of two basic networks: - Asini, produce digestive enzymes - Island of the pancreas, produce hormones. Pancreas to release digestive enzymes into the duodenum and release hormones into the blood.
Digestive enzymes produced by cells asini and flows through various channels into the pancreatic duct. Pancreatic duct joins the bile duct will be on the sphincter Oddi, both of which will enter into the duodenum.
Enzymes released by the pancreas to digest proteins, carbohydrates and fats. Proteolytic enzymes break down the protein into a form that can be used by the body and released in an inactive form. These enzymes will only be active if it has reached the digestive tract. Pancreas as well as releasing large amounts of sodium bicarbonate, which serves to protect the duodenum by neutralizing stomach acid.
Three hormones produced by the pancreas are: - Insulin, which serves lower blood sugar levels - Glucagon, which serves to increase blood sugar levels - Somatostatin, which functions both inhibit the release of other hormones (insulin and glucagon).
Heart
Liver is a large organ and has many functions, some of which are associated with digestion.
Nutrients from food are absorbed into the intestinal wall that is rich in blood vessels are small (capillary). This capillary blood flow into the veins that join larger veins and eventually enter the liver as the portal vein. Vena porta divided into small vessels in the liver, where the incoming blood is processed.
The blood is processed in two ways: - Bacteria and other foreign particles that are absorbed from the intestine removed - Various nutrients are absorbed from the intestine is broken down further so that it can be used by the body. Heart perform these processes at high speed, after the blood is enriched with nutrients, the blood flowed into the general circulation.
Liver produces about half of all the cholesterol in the body, the rest comes from food. Approximately 80% of cholesterol produced in the liver is used to make bile. The liver also produces bile, which is stored in the gallbladder.
Bile duct and gallbladder
Bile flow from the liver through the ducts hepatikus left and right, which subsequently merged to form common duct hepatikus. This tract was later merged with a channel originating from the gallbladder (cystic duct) to form the common bile duct. Pancreatic duct joins the common bile duct and into the duodenum.
Before eating, bile salts accumulate in the gallbladder and bile that flows only slightly from the liver. The food in the duodenum triggers a series of hormonal signals and neural signals that gallbladder contraction. As a result, bile flows into the duodenum and mix with food.
Bile has two important functions: - Helps digestion and absorption of fat - Serve in the disposal of certain wastes from the body, especially the destruction of hemoglobin from red blood cells and excess cholesterol.
Specifically bile plays a role in various processes follows: - Bile salts increase the solubility of cholesterol, fat and fat-soluble vitamins to help the absorption process - Bile salts stimulate the release of water by the colon to help move the contents - Bilirubin (bile pigment from the main) thrown into the bile as waste from the destroyed red blood cells - Drug and other wastes dumped in the bile and subsequently removed from the body - Various proteins that play a role in the function in the gall bladder removed.
Bile salts are absorbed back into the small intestine, distilled by the liver and fed back into the bile. This circulation is known as enterohepatik circulation. All of the bile salts in the body circulate as much as 10-12 times per day. In each circulation, a small amount of bile salts into the large intestine (colon). In the colon, bacteria break down the various elements of bile salts into the principal. Some of these constituents are absorbed back and the rest disposed of with feces.
Colon
Large intestine consists of: - Ascending colon (right) - Transverse colon - Descending colon (left) - Sigmoid colon (corresponding to the rectum).
Appendix (appendectomy) is a small protrusion shaped like a tube, which is located in the ascending colon, ascending colon on the border with the small intestine.
Colon produces mucus and serves to absorb water and electrolytes from the feces.
When we reach the large intestine, intestinal contents as a liquid, but when it reaches the rectum into solid form.
The number of bacteria present in the large intestine functions to digest some of the material and helps the absorption of nutrients. Bacteria in the colon also serves to make essential substances, such as vitamin K. The bacteria are essential for normal function of the intestine. Some diseases and antibiotics can cause interference with the bacteria in the intestine. The result is irritation that could cause the release of mucus and water, and there was diarrhea.
Rectum & Anus
The rectum is a room that starts from the tip of the large intestine (after sigmoid colon) and ends at the anus. Normally the rectum is empty because the faeces is stored in a higher place, namely the descending colon. If the full descending colon and feces into the rectum, then arose the desire to urinate besar.Orang adults and older children who could resist this desire, but infants and younger children have deficiencies in muscle control necessary to postpone defecation .
The anus is a hole in the tip of the digestive tract, where waste material out of the body. Most of the anus is formed from the body surface (skin) and partly from the intestine. A muscular ring (sphincter ani) keep the anus closed.