Ana 202
Harry okure
18/MHS07/040
Pharmacology 

Covid-19 is the novel corona virus discovered in the year 2019. Corona viruses stems from a genus of viruses of the family corona viridaethat causes respiratory diseases and possibly gastroenteritis in humans.
                       Trends of mutation
The corona virus has had the ability to mutate in its host were in 2012 is presented in humans as SARS-COV which denotes severe acute respiratory syndrome.
A decade later it mutated in the host and presented as MERS[2012] which stands for the middle eastern food respiratory distress syndrome . 
  Anatomical implication on the respiratory         system 
Once the virus gets into the respiratory system it attacks the alveoli. In the alveoli it gets attached to the type II pneumocyte, this cells are responsible for the the production of surfactant which decreases surface tension within the alveoli  and reduces the collapsing pressure.
MOA of virus on respiratory system 
1.) virus gets attached to the type II pneumocyte and replicates itself within the cell causing damage of the cell.
2.) this causes the release of inflammatory mediators like histamine, protaglancin.
3.) macrophage get stimulated and secretes cytokines including inferlukin I, VI and tumornecrotic factor alpha.q
4.) cytokines released causes vasodilation and capillary permeability by causing endothelial cell contraction.
5.) plasma flows out and leaks into the interstitial space and potentially into the alveoli causing alveoli edema.