Download How does Saliva break down food? and How does the esophagus

How does Saliva break down food? and How does the esophagus move food to the stomach?
Saliva moistens food for easy swallowing. A digestive enzyme called amylase (pronounced: ah-mehlace) starts to break down some of the carbohydrates in the food even before it leaves the mouth. Your
salivary glands in your mouth also release water and mucus which make the food slippery and soft so it
is easier to swallow.
Once your food is swallowed it enters a muscular tube called the esophagus. Food is moved down the
esophagus by a wave of muscular contractions called peristalsis. Peristalsis is the same method a snake
uses to swallow it’s food but we do it much faster. (http://vimeo.com/2595338) After about 6 seconds
food reaches the bottom of the esophagus. This is so strong that you can even swallow when your
mouth is lower than your stomach, such as when you bend over to drink from a stream.
How long does it take for food to move through the digestive tract?
Chewing food typically takes from 5-30 seconds, then after you swallow your food takes about 6
to 10 seconds to reach your stomach. Once the food has reached your stomach it sticks around
for about 3 to 4 hours. Then food is moved to your small intestine and takes about 3 hours to
move through the 20feet of tubing. After your food (well what’s left of it) moves through the
small intestines it moves to the large intestine where the food dries up and can remain for 18
hours to 2 days. In total food can move through your body anywhere from 24 to 72 hours.
How do the small intestines absorb food?
In the intestine partially digested food mixes with the enzymes from the pancreas and bile from the
liver. The inner wall of the small intestine is covered with millions of microscopic, finger-like projections
called villi. The villi are where the nutrients are absorbed into the body. Villi are like tones of little
bristles o the folds of the intestines. These villi have lots and lots of surface area which help absorb lots
of nutrients. Each villi contains blood vessels that help nutrients pass quickly through the intestine lining
into the blood stream.
Blood vessels
Gastroesophageal Reflux disease (GERD) – Esophagus
This is a condition where the tube of muscles that connects the esophagus with the stomach
(esophageal sphincter) allows the acidic contents for the stomach to move backward up into the
esophagus. GERD can sometimes be corrected through lifestyle changes, such as adjusting the types of
things a person eats. Sometimes, though, it requires treatment with medication.
Celiac Disease – Stomach
This is a digestive disorder caused by the abnormal response of the immune system to a protein called a
gluten, which is found in certain foods. People with celiac disease have difficulty digesting the nutrients
from their food because eating things with gluten damages the lining of the intestines over time. Some
of the symptoms are diarrhea, abdominal pain and bloating. The disease can be managed by following a
gluten-free diet.
Gastritis and Peptic Ulcers – Stomach
Under normal conditions, the stomach and duodenum are very resistant to irritation by the strong acids
produced by the stomach. Sometimes, though a bacterium called Helicobacter pylori or the chronic use
of certain medications weakesn the protective mucous coating of the stomach and duodenum, allowing
acid to get through to the sensitive lining beneath. This can irritate and inflame the lining of the stomac
or cause peptic ulcers. Sores or holes can form under the lining of the stomach and cause pain or
bleeding. Medications are usually successful in treating these conditions.
Cystic Fibrosis – Pancreas
This is a chronic, inherited illness where the production of abnormally thick mucus blocks the ducts or
passageways in the pancreas and prevents its digestive juices from entering the intestines. This makes it
difficult for a person to properly digest protein and fats. This causes important nutrients to pass out of
the body unused. To help manage their digestive problems, people with cystic fibrosis can take digestive
enzymes and nutritional supplements.
What causes farts?
Flatulence, also known as farting, is the act of passing intestinal gas from the anus. Gas in the
gastrointestinal tract has only two sources. It is either swallowed air or is produced by bacteria
that normally inhabit the intestines, primarily the colon. Swallowed air is rarely the cause of
excessive flatulence.
The usual source is the production of excessive gas by intestinal bacteria. The bacteria produce
the gas (hydrogen and/or methane) when they digest foods, primarily sugars and
polysaccharides (for example, starch, cellulose), that have not been digested during passage
through the small intestine. (The bacteria also produce carbon dioxide, but the carbon dioxide
is so rapidly absorbed from the intestine that very little passes in flatus.)
Starches are a common source of intestinal gas. Starches are produced by plants and are
composed of long chains of sugars, primarily fructose. Common sources of different types of
starch include wheat, oats, potatoes, corn, and rice. Rice is the most easily digested starch and
little undigested rice starch reaches the colon and the colonic bacteria. Accordingly, the
consumption of rice produces little gas. In contrast, some of the starches in wheat, oats,
potatoes, and, to a lesser extent, corn, all may reach the colon. These starches, therefore, may
result in the production of appreciable amounts of gas. Finally, certain fruits and vegetables,
for example, cabbage, also contain poorly digested starches that reach the colon and result in
the formation of gas.
Small amounts of air are continuously being swallowed and bacteria are constantly producing
gas. Contractions of the intestinal muscles normally propel the gas through the intestines and
cause the gas to be expelled. Flatulence (passing intestinal gas) prevents gas from accumulating
in the intestines.
However, there are two other ways in which gas can escape the intestine. First, it can be
absorbed across the lining of the intestine into the blood. The gas then travels in the blood and
ultimately is excreted in the breath. Second, gas can be removed and used by certain types of
bacteria within the intestine. In fact, most of the gas that is formed by bacteria in the intestines
is removed by other bacteria in the intestines. (Thank goodness!)