You do it this way; the shift in perspective can bewilder the reader. Consistency is the chief virtue here. There is, of course, a difference between a process essay that tells readers how to do something and a process essay that describes the process by which something gets done by someone else or by nature.here is, of course, a difference between a process essay that tells readers how to do something and a process essay that describes the process by which something gets done by someone else or by nature.
In the human heart, the pulmonary trunk (pulmonary artery or main pulmonary artery) begins at the base of the right ventricle. It is short and wideâapproximately 5 centimetres (2.0 in) in length and 3 centimetres (1.2 in) in diameter.
Each alveolus is surrounded by a nest of blood capillaries that are supplied by small branches of the pulmonary artery. In summary, the pulmonary circuit begins with the pulmonary trunk, which is a large vessel that ascends diagonally from the right ventricle and branches into the right and left pulmonary arteries.