What Does It Do?
Understanding Anatomy
If we enter our mouth and into our throat, we have two tubes connecting the outside to our insides, the trachea and the esophagus. The trachea branches off into our two bronchial tubes, each leading to one lung. Traveling into our lung, the bronchial tube branches into more tubes, like the roots of a tree, called bronchioles. You may have heard of the condition bronchitis, a respiratory condition affecting our bronchioles. Well, at the end of each bronchiole are multiple sacs of alveoli, where we transfer oxygen and carbon dioxide.
Inside your alveoli are pneumocytes, type 1 pneuomcytes and type 2 pneumocytes. When the virus enters our respiratory system, they attack the type 2 pneumocytes. These type 2 pneumocytes produce surfactants for your lungs. Surfactants are molecules that reduce the collapsing pressure in your lungs. Without these, it would be pretty hard to breath, and almost all of the time we would be suffering from collapsed lungs. Once the virus is inside the type 2 pneumocyte, they use that cell to make copies of itself. One virus can make thousands of copies of itself to attack other cells. When the virus is done copying itself, it kills the cell it was using. That damaged cell signals for the immune system, This causes a series of events as a response of the immune system, one of them being the blood vessels dilate. Blood is the body's transportation system for a lot of important materials like hormones and other things. But because the blood vessels dilate, plasma can leak in to spaces surrounding the alveoli and even inside of the alveoli. This causes increased pressure on the alveoli, and because our surfactant production was reduced, the alveoli eventually collapse under pressure, causing reduced gas exchange, and ultimately making it harder to breathe. The virus isn't done. Neutrophils, an immune system cell, starts to destroy the virus, but end up damaging other cells. They move to the center of the alveoli which alters gas exchange even more. As a response, we start coughing. The reason we are coughing is we are trying to expel the collapsed alveoli from our system. Hormones in our bodytravel to our hypothalamus in our brain to create more immune responses. One of the responses is increasing body temperature to burn out the virus, which causes a fever. As a stress response, our heart rate increases, pumping more blood through the body. This also increases our respiration rate, along with our struggling ability to create gas exchange. In most cases, the body can fight of the virus, and these are the worst symptoms we have to worry about. But in more sever cases, it can spread to the body, and cause septic shock, which can be fatal if not treated properly. However, for most of the population, we only need to focus on the three main symptoms, cough, fever, and respiratory problems. Some of the population need not worry at all, they could present with no symptoms.