How Is Blood Transported Throughout The Body

Our body needs blood to allow transport of nutrients to the different cells to function. In it we mainly find

- White blood cells - Cells used in our immune system

- Red blood cells - These contain haemoglobin and iron groups to carry oxygen

Red blood cells are used to allow oxygen to be transported through our body. Oxygen enters our body via a difference of pressures, where the atmospheric pressure is greater than the pressure within our bodies. As we breathe in, or inspire, our diaphragm contracts and our lung fields expand. This causes the decreased pressure in our thoracic cavity, allowing for air to enter and pass through and into the alveoli of the lungs. Once here, the oxygen passes along the alveoli, across and into the red blood cells, as they’re diffuse down a gradient. The capillaries surrounding the alveoli then return blood to the heart

1. Blood enters into the left atria via arteries which supply it

2. As this contracts, the mitral valves open due to a difference in pressure, and cause blood to pass into the left ventricle

3. As blood pools into the ventricle, it causes a difference of pressure to build up which then causes the mitral valves to shut

4. Aortic valves are then forced open which causes blood to flow out of the heart and into the aortas to supply the body.

5. Deoxygenated blood, or blood with no oxygen, is returned to the heart via the inferior and superior vena cava, which allows blood to enter into the right atria. As there is a pressure difference the blood pools into the right atria causing the tricuspid valves to remain shut

6. As blood pressure increases due to increased blood in the right atria, tricuspid valves then open to allow blood into the right ventricle of the heart

7. Blood enters the right ventricle, and then causes tricuspid valves to shut, and the pulmonic valves to open

8. As pulmonic valves open, blood passes out of the heart via the pulmonary aortas, which supply the right and left lungs, and branch into capillaries which surround the alveoli and the process returns once again