Control of cardiac output 1 per page

the pulmonary circulation has a lower pressure than the system due to a 3 main factors

the right side of the heart (which pumps into pulmonary circ) has a lower muscle level so less pressure/cardiac contractility (force) is therefore produced by the right ventricle

there is more blood flow resistance in the pulmonary circulation

the pulmonary circulation is much shorter than the systemic circulation and therefore blood has less of a distance to travel in pulmonary circulation than within systemic

the ventricles during systole produce high amounts of pressure to push blood out of the ventricles into the great vessels they produce up to 120mmHg of pressure.

the ventricles during diastole do not produce high amounts of pressure, the atria have a higher pressure level during this point which allows the blood in the atria to passively and actively flow from themselves into the ventricles

as the circulatory system goes on proportional pressure:vessel increases due to compliance decreasing (as vessels become less elastic/large) however overall pressure decreases and the resistance through the circulatory system caused by numerous different vessel types and quantities constantly changing reduces the speed of blood flow