This essay will explain the function of the respiratory, digestive and cardiovascular systems and how they work together to produce nutrients and oxygen to the cells for cellular respiration (energy for the body) The first system in the body is the digestive system. When food enters the mouth the salivary glands secrete saliva which mixes with the food. This makes it easy to chew and swallow. Once the food has been chewed enough the food travels down the oesophagus to the stomach. Once the food has reached the stomach, the food goes through the process of catabolism. This process which the food is broken down into smallest nutritional components. What has been left is now sent to the small intestine. The small intestines is about 1 cell thick this makes the next part of the process. The nutrient is now diffused through the walls and into the blood stream. The second process is the respiratory system. This system is responsible for the breathing process. This is done by using energy to inhale oxygen (O2) and to exhale carbon dioxide (CO2). This process is also known as gaseous exchange. This done through the alveoli, which has a cell thick wall to maximise the diffusion. Oxygen is diffused from the lungs into the blood so the red blood cells get oxygenated. And for this to happen carbon dioxide is taken from the blood and is diffused through to lungs to be exhaled.
The third and final process is cardiovascular system. This is the main transportation system for the energy. The blood is pumped from the heart around the body. The blood is pumped through the arteries and then through the veins and the capillaries. The capillaries then run around the outside of the alveoli which diffuse oxygen and carbon dioxide at the lungs. The blood also carries energy around the body all of the bodies tissues, organs and cells. Without the digestive and respiratory systems this system would not be able to work.
Please join StudyMode to read the full document