Human Body Systems
This site complies with the HONcode standard for trustworthy health information: Please try again later. Unfortunately, our editorial approach may not be able to accommodate all contributions. The pancreas secretes an incredibly strong digestive cocktail known as pancreatic juice, which is capable of digesting lipids, carbohydrates, proteins and nucleic acids. On average, the human adult male's small intestine is 6.
From here, food travels to the esophagus or swallowing tube. The esophagus is a muscular tube extending from the pharynx to the stomach. By means of a series of contractions , called peristalsis, the esophagus delivers food to the stomach.
Just before the connection to the stomach there is a "zone of high pressure," called the lower esophageal sphincter; this is a "valve" meant to keep food from passing backwards into the esophagus. The stomach is a sac-like organ with strong muscular walls. In addition to holding the food, it's also a mixer and grinder. The stomach secretes acid and powerful enzymes that continue the process of breaking down the food.
When it leaves the stomach, food is the consistency of a liquid or paste. From there the food moves to the small intestine. Made up of three segments, the duodenum, jejunum, and ileum, the small intestine is a long tube loosely coiled in the abdomen spread out, it would be more than 20 feet long. The small intestine continues the process of breaking down food by using enzymes released by the pancreas and bile from the liver.
Bile is a compound that aids in the digestion of fat and eliminates waste products from the blood. Peristalsis contractions is also at work in this organ, moving food through and mixing it up with digestive secretions.
The duodenum is largely responsible for continuing the process of breaking down food, with the jejunum and ileum being mainly responsible for the absorption of nutrients into the bloodstream.
Three organs play a pivotal role in helping the stomach and small intestine digest food:. Among other functions, the oblong pancreas secretes enzymes into the small intestine. These enzymes break down protein, fat, and carbohydrates from the food we eat. The liver has many functions, but two of its main functions within the digestive system are to make and secrete bile, and to cleanse and purify the blood coming from the small intestine containing the nutrients just absorbed.
The gallbladder is a pear-shaped reservoir that sits just under the liver and stores bile. Bile is made in the liver then if it needs to be stored travels to the gallbladder through a channel called the cystic duct.
During a meal, the gallbladder contracts, sending bile to the small intestine. Once the nutrients have been absorbed and the leftover liquid has passed through the small intestine, what is left of the food you ate is handed over to the large intestine, or colon.
The colon is a 5- to 6-foot-long muscular tube that connects the cecum the first part of the large intestine to the rectum the last part of the large intestine. It is made up of the cecum, the ascending right colon, the transverse across colon, the descending left colon, and the sigmoid colon so-called for its "S" shape; the Greek letter for S is called the sigma , which connects to the rectum.
Stool, or waste left over from the digestive process, is passed through the colon by means of peristalsis contractions , first in a liquid state and ultimately in solid form as the water is removed from the stool. A stool is stored in the sigmoid colon until a "mass movement" empties it into the rectum once or twice a day. It normally takes about 36 hours for stool to get through the colon. The stool itself is mostly food debris and bacteria. Teeth, which are part of the skeletal system, play a key role in digestion.
In carnivores, teeth are designed for killing and breaking down meat. The BioDigital Human ]. Swallowing pushes chewed food into the esophagus, where it passes through the oropharynx and hypopharynx.
At this point, food takes the form of a small round mass and digestion becomes involuntary. A series of muscular contractions, called peristalsis, transports food through the rest of the system. After an hour or two of this process, a thick semi-liquid paste, called chyme, forms. The next stop for the chyme is the small intestine, a foot 6-meter tube-shaped organ, where the majority of the absorption of nutrients occurs. The nutrients move into the bloodstream and are transported to the liver.
The liver creates glycogen from sugars and carbohydrates to give the body energy and converts dietary proteins into new proteins needed by the blood system. The liver also breaks down unwanted chemicals, such as alcohol, which is detoxified and passed from the body as waste, the Cleveland Clinic noted. Whatever material is left goes into the large intestine. The function of the large intestine, which is about 5 feet long 1. Also called the colon, it has four parts: This is where water from the chyme is absorbed back into the body and feces are formed primarily from water 75 percent , dietary fiber and other waste products, according to the Cleveland Clinic.
Feces are stored here until they are eliminated from the body through defecation. Many symptoms can signal problems with the GI tract, including: According to the Centers for Disease Control CDC , 51, Americans died from colon cancer in the most recent year for available data.