Notes

The lungs and respiratory system allow oxygen in the air to be taken into the body, while also enabling the body to get rid of carbon dioxide in the air breathed out. Respiration is the term for the exchange of oxygen from the environment for carbon dioxide from the body's cells.


Your heart sits between your lungs in the middle of your chest. Its job is to pump blood to all of the organs, tissues, and cells in your body through blood vessels (arteries and veins). This is really important because blood delivers the oxygen and nutrients that every cell needs and removes dangerous wastes.



The stomach is a muscular organ located on the left side of the upper abdomen. The stomach receives food from the esophagus. As food reaches the end of the esophagus, it enters the stomach through a muscular valve called the lower esophageal sphincter. The stomach secretes acid and enzymes that digest food.



the liver produces proteins that are important in blood clotting. It is also one of the organs that break down old or damaged blood cells. The liver plays a central role in all metabolic processes in the body. In fat metabolism the liver cells break down fats and produce energy.

The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine. Every day, the two kidneys filter about 120 to 150 quarts of blood to produce about 1 to 2 quarts of urine, composed of wastes and extra fluid.

The small intestine is the part of the intestines where 90% of the digestion and absorption of food occurs, the other 10% taking place in the stomach and large intestine. The main function of the small intestine is absorption of nutrients and minerals from food.

Ions and nutrients released by gut bacteria and dissolved in water are also absorbed in the large intestine and used by the body for metabolism. The dried, condensed fecal matter is finally stored in the rectum and sigmoid colon until it can be eliminated from the body through the process of defecation.