Organ Systems:5.) Absorption and Excretion:
Food is taken into the body to provide the raw materials for building body tissues. In addition food molecules are broken down for energy. Oxygen is also taken in, because it is a necessary component in the chemical reactions wherein larger molecules are broken into smaller molecules for energy.
The organs of the
digestive system take in food and break it down into small molecules that can be absorbed into the blood and lymph. The absorbed food molecules are then transported throughout the body via the blood and lymph, to be absorbed into body cells. The body cells use these food molecules as raw materials and for energy production. Another function of the digestive system is to eliminate ingested indigestible matter from the body.
The
respiratory system absorbs oxygen from the air and delivers it to the blood, which can then transport it to body tissues. The respiratory system also removes the metabolic waste product carbon dioxide from the blood and expels it from the body.
The
urinary system removes metabolic waste products and other potentially harmful substances from the blood and dilutes them in water. The result is known as
urine, which is excreted from the body.
The digestive system takes in and processes food, then eliminates indigestible matter.
The respiratory system takes in oxygen and excretes harmful carbon dioxide.
The urinary system removes metabolic wastes and other
potentially harmful substances from the body.