Back to B2 Home
B2 H) Circulatory System – Introduction
B2 H) Circulatory System – Introduction
What Makes Up the Circulatory System?
There are 3 different parts of the circulatory system. These are:
There are 3 different parts of the circulatory system. These are:
- The heart, which is the pump of the system
- Blood vessels, which carry the blood around the body. There are 3 different types of blood vessels; arteries, veins and capillaries.
- Blood, which is the transport medium. Blood carries a variety of different substances, such as different types of cells, carbon dioxide, nutrients, hormones etc…
Double Circulatory System
Mammals have a double circulatory system. One system is the pumping of blood from the heart to the lungs and back to the heart; this system is known as the pulmonary circulatory system. The other circulatory system is where blood is pumped from the heart around the rest of the body and back to the heart; this system is known as the systemic circulatory system. The very simple diagram below shows the pulmonary and the systemic circulatory systems. The lungs are at the top and the body is represented as a bicep.
Mammals have a double circulatory system. One system is the pumping of blood from the heart to the lungs and back to the heart; this system is known as the pulmonary circulatory system. The other circulatory system is where blood is pumped from the heart around the rest of the body and back to the heart; this system is known as the systemic circulatory system. The very simple diagram below shows the pulmonary and the systemic circulatory systems. The lungs are at the top and the body is represented as a bicep.
There are two different types of blood in the circulatory systems; oxygenated blood and deoxygenated blood. Oxygenated blood is blood that contains lots of oxygen and very little carbon dioxide. Deoxygenated blood is blood that contains very little oxygen and lots of carbon dioxide.
The pulmonary circulatory system pumps deoxygenated blood from the heart to the lungs. In the lungs, oxygen enters the bloodstream and carbon dioxide leaves the bloodstream. This results in oxygenated blood, which travels back to the heart.
The oxygenated blood is then pumped out on the second circulatory system from the heart to the rest of the body (represented as a bicep). At the rest of the body, oxygen leaves the bloodstream and carbon dioxide enters the bloodstream. This results in deoxygenated blood, which travels back to the heart.
The places where we have oxygenated and deoxygenated blood are shown on the diagram below.
The pulmonary circulatory system pumps deoxygenated blood from the heart to the lungs. In the lungs, oxygen enters the bloodstream and carbon dioxide leaves the bloodstream. This results in oxygenated blood, which travels back to the heart.
The oxygenated blood is then pumped out on the second circulatory system from the heart to the rest of the body (represented as a bicep). At the rest of the body, oxygen leaves the bloodstream and carbon dioxide enters the bloodstream. This results in deoxygenated blood, which travels back to the heart.
The places where we have oxygenated and deoxygenated blood are shown on the diagram below.
There is a greater blood pressure in the systemic circulatory system (around the body) compared to the pulmonary system (to the lungs).