Quiz by: IUTALILLE1
When you put food in your mouth, it’s starting a journey through your digestive system.
The digestive system is a tube-like structure up to 9 meters long running from the mouth to the anus.
Some nutrients are made up of large molecules. These have to be broken down into molecules small enough to dissolve in your blood.
Only then can your body use them.
This process is called digestion.
Digestion starts in your mouth. Your teeth are designed to physically break up food into smaller pieces.
At the same time, saliva is released.
This moistens in the food and contains the digestive enzyme : amylases.
When you swallow a mouthful of food, it’s pushed down your throat to your oesophagus. The oesophagus leads from your mouth to your stomach.
Muscles in the wall of the oesophagus contract pushing the food along.
This process is called peristalsis.
You could feel these muscular contraction but that doesn’t mean it’s happening
To examine the digestive system, doctors can give patients a barium meal. This contains barium sulfate which is up black on an X ray image. The progress on the barium meal can be followed on the screen it takes about 6 seconds for a mouthful of food to reach the stomach.
This model shows the typical size and shape of your stomach compared to your other organs.
The stomach has elastic walls which stretches the food collected inside.
Every now and again, the stomach muscles contract to churn the food. In a folded lining of the stomach…There are many gastric pits, each pit contains the gland which produces the gastric juice. Gastric juice is acidic and contains the digestive enzyme: pepsin. Pepsin works on protein like in eggs.
Foods spends 3 to 4 hours in your stomach once it’s been turned into a liquid. It’s released into the first part of the small intestine.
Mixing with it is pancreatic juice released from the pancreas. This juice contains amylase, protease and lipase. Amylase completes the digestion of starch, protease continues the digestion of protein.
The margarine in a sandwich contains fat. This is not digested by the lipase. By now all the digestible material from your sandwich has been broken down into small molecules. These are smaller enough to pass through the lining in the intestine into your blood. The inner surfaces in the smaller intestine is lined with thousands of
tiny projections called villi. The molecules of digestive food can pass into the cells lining the villi and then into the bloodstream.
This process is called absorption.
The thousands of villi increase the surface area of the small intestine.
The intestine wall is also folded, so further increasing its surface area for absorption.
Some food can’t be broken down and absorbed: Most of this is fiber. Its stays in the gut eventually passing out of the body through the anus. However its passage through the bodys not to waste it helps keep the whole digestive system working effectively.
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