Monday 13th January 2020
LC: To sustain and develop ideas logically in non-narrative writing
How The Circulatory System Works.
The human circulatory system is made up of the heart, blood vessels (veins and arteries) and the lungs. The heart sends nutrients and oxygen to the blood. The veins will return the deoxygenated blood back to the heart. Did you know that the heart beats 100,000 times a day! The blood cells goes down the right atrium, then tricuspid valve, (it’s like a doorway) next the blood cell goes into the right ventricle, finally it goes through the pulmonary valve. Through out the journey the blood cell would give oxygen to the different parts of the body and would take some of the (CO2) carbon dioxide from the blood. After, the returning red blood cells goes through the left atrium, then the mitral valve, next it goes through the left ventricle then finally the aortic valve.
About 8 million blood cells die in the human body every second, and the same number are born each second. Within a tiny droplet of blood, the are 5 million red blood cells. If you were to lay out all of the arteries, capillaries and veins in one adult, end-to-end, they would stretch about 60,000 miles (100,000 kilometers). By comparison, the circumference of the Earth is about 25,000 miles (40,000 kilometers). That means that a person’s blood vessels could wrap around the plant approximately 2.5 times! The heart is the only muscle that works constantly and only stops after we die.