How circulatory system is involved with digestion and excretion?

The circulatory system and the digestive system work together as follows.

• The digestive system breaks the food that is consumed by an organism into smaller pieces that the body can use such as amino acids, sugars, and vitamins. These nutrients are absorbed into cells The cells then use or convert the nutrients into biomolecules that are needed to carry on everyday functions. For example, cellular respiration occurs within the mitochondria of cells. During cellular respiration, the sugar glucose and oxygen are converted into water, carbon dioxide and an energy source called adenosine triphosphate (ATP).

The circulatory system and excretory system are connected in the following ways.

• The circulatory system carries metabolic wastes such as urea and uric acid to the kidneys. The kidneys then excrete the waste.


• Blood pressure is controlled by the excretory system.


• The acid/base balance of the body is controlled by the body. In return, the oxygen-carrying capacity of the hemoglobin that is housed within the red blood cells is dependent on the acid/base balance.