These are some ways how scientists and engineers develop, use and refine models.
1. Imagine. They have to know what exactly trying to model. They have to imagine and brainstorm what are the things to be considered.
2. Reason. Next, they need to answer the questions brought from their brainstorming. They need to be able to reason out.
3. Calculate and Predict. Once they know it, that's the time they can start modelling and calculate - and predict.
Answer:
pulmonary circuit, systemic circuit
Explanation:
The circulatory system consists of 2 circuits -
pulmonary circuit
systemic circuit.
The pulmonary circuit carries deoxygenated blood. The right auricle receives the impure blood by superior and inferior vena cava, then the blood enters the right ventricle. From the right ventricle, the deoxygenated blood moves to the lungs by the pulmonary artery.
In the lungs, the deoxygenated blood gets oxygenated and enters the left ventricle through pulmonary veins. The pureblood then passes into the left ventricle and then the ventricle pumps the oxygenated blood to different parts of the body. This blood passes to the body aways from the heart by aorta. When the blood gets deoxygenated, it again enters the right auricle. In this way, double circulation occurs and both types of blood do not mix together.
