The cardiovascular system (specifically the circulatory system) works with the respiratory system to get oxygen to the tissues,
cells, and organs. Once you inhaled oxygen and it made it to the lungs, the blood capillaries, and to the alveoli for the gas exchange. Finally the CO2 is then able to be exhaled and the blood is oxygen filled. The process of circulation and the two systems working together begins with the heart. In the heart, the right ventricle and atrium
are where blood is received from the veins. Deoxygenated blood flows into the right atrium. When the heart muscle
relaxes, the blood is emptied from the atrium and into the right ventricle. The right ventricle then pushes the blood
through the pulmonary valve and into the pulmonary artery, where the blood is delivered to the lungs to be
replenished with oxygen. The blood is then returned to the left side of the heart. Since the right side, the left atrium
receives the blood sending it to the ventricle when the heart muscle relaxes. Finally, the blood is pushed to the aorta
and delivered to the rest of your body.
Well I don't know much but I do know that they are different because unicellular can self produce which means they can reproduce without someone else but multicelluar needs someone else to reproduce
