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.
The pulmonary circuit begins at the semilunar valve of the pulmonary trunk that carries deoxygenated blood to the lungs. The pulmonary trunk divides into left and right pulmonary arteries that go to each lung. Blood is oxygenated in capillaries that flow through the alveoli of the lungs.Oxygenated blood is then returned to the left atrium of the heart by four pulmonary veins.he pulmonary trunk divides into left and right pulmonary arteries that go to each lung. Blood is oxygenated in capillaries that flow through the alveoli of the lungs. Oxygenated blood is then returned to the left atrium of the heart by four pulmonary veins.