Not only does the circulatory system keep our cells healthy, but it also keeps us alive. The heart receives signals from the rest of the body that direct how hard it needs to pump to properly supply the body with what it needs, according to Nemours. For example, when asleep, the body sends electrical signals to the heart that tell it to slow down. When participating in heavy exercise, the heart receives the message to pump harder to deliver extra oxygen to the muscles.
What are the main circulation systems?
1.systemic circulation
The systemic circulation provides organs, tissues and cells with blood so that they get oxygen and other vital substances. In the systemic circulation, the left ventricle pumps oxygen-rich blood into the main artery (aorta). The blood travels from the main artery to larger and smaller arteries and into the capillary network. There the blood drops off oxygen, nutrients and other important substances and picks up carbon dioxide and waste products. The blood, which is now low in oxygen, is collected in veins and travels to the right atrium and into the right ventricle.
2.pulmonary circulation
The pulmonary circulation is where the fresh oxygen we breathe in enters the blood. At the same time, carbon dioxide is released from the blood. The right ventricle pumps low-oxygen blood into the pulmonary artery, which branches off into smaller and smaller arteries and capillaries. The capillaries form a fine network around the pulmonary vesicles (grape-like air sacs at the end of the airways). This is where carbon dioxide is released from the blood into the air inside the pulmonary vesicles, and fresh oxygen enters the bloodstream. When we breathe out, carbon dioxide leaves our body. Oxygen-rich blood travels through the pulmonary veins and the left atrium into the left ventricle. The next heartbeat starts a new cycle of systemic circulation.
3.blood circulation
The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body. It consists of the heart and the blood vessels running through the entire body. The arteries carry blood away from the heart; the veins carry it back to the heart. The system of blood vessels resembles a tree: The “trunk” – the main artery (aorta) – branches into large arteries, which lead to smaller and smaller vessels. The smallest arteries end in a network of tiny vessels known as the capillary network. Blood circulation starts when the heart relaxes between two heartbeats: The blood flows from both atria (the upper two chambers of the heart) into the ventricles (the lower two chambers), which then expand. The following phase is called the ejection period, which is when both ventricles pump the blood into the large arteries.
Oxygen enters the bloodstream through tiny membranes in the lungs that absorb oxygen as it is inhaled. As the body uses the oxygen and processes nutrients, it creates carbon dioxide, which your lungs expel as you exhale. A similar process occurs with the digestive system to transport nutrients, as well as hormones in the endocrine system. These hormones are taken from where they are produced to the organs they affect.