In Depth: Circulatory
Think of you circulatory system as a packed string of interstate highways: every vehicle on the road has a very specific and helpful function. So long as no one starts backing up traffic, everyone gets where it needs to go in an orderly fashion.
Combined with the cardiovascular system, the circulatory system helps fight disease, help the body maintain a normal body temperature, and provide the right chemical balance to provide the body’s homeostasis, or state of balance among all its systems.
The circulatory system consists of four major components:
- The Heart: About the size of two adult hands held together, the heart sits near the center of the chest. Thanks to consistent pumping, the heart keeps the circulatory system working at all times.
- Arteries: Arteries carry blood rich in oxygen away from the heart and where they need to go.
- Veins: Veins carry deoxygenated blood to the lungs where they receive oxygen.
- Blood: Blood is the carrier of nearly everything for the body. It transports hormones, nutrients, oxygen, antibodies, and other important things needed to keep the body healthy.
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.
The system works thanks to constant pressure from the heart and valves throughout the body. This pressure ensures that veins carry blood to the heart and arteries transport it away from the heart. (Hint: to remember which one does which, remember that that “artery” and “away” both begin with the letter A.)
There are three different types of circulation that occur regularly in the body:
- Pulmonary circulation: This part of the cycle carries oxygen-depleted blood away from the heart, to the lungs, and back to the heart.
- Systemic circulation: This is the part that carries oxygenated blood away from the heart and to other parts of the body.
- Coronary circulation: This type of circulation provides the heart with oxygenated blood so it can function properly.