Life Science- Digestive System Flashcards
Main organs
Liver, oesophagus, stomach, large intestine, small intestine, anus and rectum.
Liver
Large organ where extra sugar is stored, and alcohol and other poisons are broken down.
Oesophagus
A tube from the mouth to the stomach. It has muscles are round it that push food down to the stomach.
Stomach
Bag-like organ which mixes and digests food to make it soluble in water.
Large intestine
1,5 m tube in which water is absorbed into the bloodstream.
Small intestine
6m+ narrow tube where food is digested and made soluble.
The digested food is absorbed through the intestine walls into the blood vessels.
Anus
An opening where feces leaves the body.
Rectum
A tube connected to the anus that stores waste until it leaves the body.
Processes
Ingestion, digestion, absorption and egestion.
Ingestion
Taking in food and chewing it into small pieces.
Digestion
Ingested food is further broken down into smaller, soluble pieces.
Absorption
When soluble food molecules from the intestines are take up or pass into the bloodstream.
Egestion
Undigested food is removed from the body as feces.
Health issues
Ulcers, diarrhea, liver cirrhosis and anorexia nervosa.
Ulcers
The stomach is lined with a mucus layer that protects it form strong stomach acids and chemical substances that digest food. Sometimes a small area of mucus lining breaks down the stomach wall’s damaged by stomach acid. Acid eats away into the stomach wall, forming ulcers. It can cause bleeding and lots of pain in the stomach.
Diarrhea
Sometimes bacteria and protests get into our drinking water and infect people causing diseases such as cholera and amoebic dysentery (waterborne diseases). In many informal settlements, there are inadequate sanitation and purification facilities. An infected person will suffer from diarrhea and vomiting, which causes dehydration. Dehydration causes weight loss, skin to wrinkle and eyes to become sunken. If fluid and electrolytes aren’t replaced, the person will fall into a coma and eventually die.
Liver Cirrhosis
Long-term damage of the liver. Excessive amounts of alcohol, viral infections or bad reactions to some medicine damage the liver. Damaged liver cells from scar tissue, and large areas of scar tissue separate working liver cells so that the liver can’t work properly.
Anorexia nervosa
‘Anorexia’ from the Greek word meaning lack of appetite. An eating disorder where the person will stop eating even though they have access to healthy foods. It is more common amongst teenagers, especially boys. A very dangerous disease because a person can become so thin that they damage their kidneys and reproductive system. Sometimes this damage can lead to death.
