The Respiratory System of the Red Fox
The respiratory system of the red fox involves the exchanging of two gases: oxygen and carbon dioxide. Obtaining oxygen is necessary for the red fox because the oxygen is then used in the process of cellular respiration. Cellular respiration is the process in which glucose is broken down to produce ATP, or energy. Oxygen and glucose will enter the body and thus to the cells, where ATP is then produced in the mitochondria for the red fox to use. With this ATP, carbon dioxide and water are produced. Carbon dioxide is a waste that is then excreted out the body.Without celluar respiration, the red fox is unable to survive.
The oxygen is obtained in the air for the red fox. The red fox does not have to move through the air to actually get the oxygen, because it is constantly engulfed by oxygen/air at all times.
In the respiratory system of the red fox, air (oxygen) will enter through the nares (nostrils, and then continues to the nasal cavity, then to the trachea, then through the bronchi to the bronchioles and lastly to the alveoli. The nasal cavity filters bacteria in the air, and warms and moistens it as well. The trachea is basically the red fox's wind pipe, so it allows the gases to travel in and out of the red fox. The bronchi are the tubes leading into the lungs, that also allow air to travel further into the red fox for necessary gas exchange. The bronchioles, which are located in the lungs, break off to form the alveoli which is where the gas exchange really takes place. Alveoli is where diffusion occurs when oxygen diffuses into the blood. The red fox also has a
larynx, or voice box, an epiglottis which is closed while it is breathing and open when it is eating. (1)
The red fox has a way of cooling itself down in the respiratory system. Since dogs are unable to sweat, when the red fox overheats, it will begin to breathe harder, or pant. This mechanism exchanges the warm air inside the body with cooler air from the outside environment. Moisture throughout the respiratory system will evaporate as well, which also helps cool the red fox down even further. (2)
(1) http://www.vetmed.wsu.edu/cliented/anatomy/dog_resp.aspx
(2) http://www.peteducation.com/article.cfm?c=2+2083&aid=515