?The heart is one of the most important organs in your body. So what does it do? It’s function is to pump blood to all the other organs. But the heart can not function alone, it has other organs and blood vessels helping it. The human heart is a pear shaped and about the size of a human fist. It is made of muscle and there are three different layers. The outer layer is called the epicardium. The middle layer is called the myocardium which is made of muscles that contract. The inner layer is called the endocardium, this layer is in contact with the blood.
The heart is divided into four chambers. The left side and the right side, which is then divided into atriums and ventricles. The atriums are the top chambers and the ventricles are the bottom chambers. The right side pumps blue blood (deoxygenated) while the left side pumps red blood. (oxygenated) The blood in the heart flows in one direction at a constant rate which means none of the chambers get overfilled. But what happens when we start running and needing more blood? The heart still goes at a constant rate but only faster. The normal rate for an adult is 72 beats per minute.
Then for the blood from flowing backward, there are tricuspid, bicuspid, aortic, and pulmonary valves. The blood goes from the atriums to the ventricles this is never changed or swapped around. Blue blood first enters the heart from either the inferior vena cava or the superior vena cava. The blood doesn’t come randomly from either one of these veins. All the deoxygented blood from parts of the body above the heart, comes in throught the superior vena cava into the left atrium. Then all the deoxygenated blood from parts of the body below the heart, comes from the inferior vena cava into the heart.
Once there, it is pumped into the right ventricle through a flap called the tricuspid valve. From the right ventricle it goes through the pulmonary valve into the pulmonary artery. From there it goes to the lungs where it becomes oxygenated from the air, then returns to the heart through the pulmonary veins. From the pulmonary veins it goes to the left atrium. It is then pumped to the left ventricle through the mitral valve. This is the last chamber in which the blood is in, before it leaves to the aorta passing through the aortic valve. From the aorta which is the largest artery, it is then pumped to other parts of the body.
The arc of the aorta is where smaller arteries take blood to organs above the heart. So blood pumps through the heart but what is actually blood? There are three main components of blood. The white blood cells, red blood cells and platelets. The white blood cells are part of the immune system and fights germs and infections. The white blood cells have a continous job of looking out for signs of diseases. When a germ does appear, the white blood cells can do either of two things, surround and devour the bacteria or produce protective antibodies which overpowers the germ.
The white blood cells life span is from around a couple of days to a week. In a drop of blood there is anywhere from 7,000 to 25,000 white blood cells. The number of white blood cells will increase if the infection fights back. Yet if there is a consistantly high number of white blood cells this could be a symptom of leukemia. A patient with leukemia has about 50,000 white blood cells in a drop of blood. The second component red blood cells has the most important blood duty, which is to transport oxygen to other parts of the body and remove waste.
There is about a million red blood cells in a drop of blood. Without blood the human body would slowly die. The reason the red blood cells are bright red is because of the chemical called hemoglobin. Hemoglobin contains iron which is excellent for transporting oxygen. This is because oxygen particles attach to iron. Then when the blood is passing through the body the hemoglobin is released. Then the empty hemoglobin molecules bond with waste gases which transports it away. Red blood cells eventually die, this happens about every 120 days. But our body is constantly making new blood.
The final element of blood is platelets, which is more of a protection for the body when it loses excesive amounts of blood. When we start bleeding the platelets stick together and try to block the blood flow. They are made of calcium and vitamin K. When blood is exposed to air it starts to clot. A scab is just an external clot. There are four types of blood types. A,B,AB and O. The blood types all matter if there is antibodies in the plasma and if there is antigens in the red blood cells. It is important to know what blood type a person is, when they are having a blood transplant.
Two blood types won’t go together. This will cause them to clump and cause fatal blockages in blood vessels. The lungs also help in the process of changing the deoxygenated blood to oxygenated blood. There are two lungs in the human body and the left one is slightly smaller. This is because the heart takes up this room to fit in the chest. There are three lobes in the right lung and two in the left lung. Another major organ that helps in filtering blood is the kidneys. Without our kidneys our body would just slowly die. Our kidneys job is to remove the waste from our blood.
This waste is poisonous in high amounts but our body can survive in low amounts. Every hour blood circulates through our kidneys twelve times. For every 200 litres of blood the kidneys filter there is 1-2 litres of toxic waste. There are many different functions of the kidneys. They control your blood pressure, maintain the minerals in your bones which keep them healthy and help to keep your water balance. To connect all these organs togther and let blood flow to them there are blood vessels. The main ones are veins, arteries and capillaries. The veins are the ones that carry the blood towards the heart.
Veins are made out of connective tissue and are normlly smaller than arteries. This is because arteries normally start near the heart and need to be flexible to cope with the pressure comming from the heart. Arteries are another blood vessel these carry blood away from the heart to other organs. Normally ateries carry oxygenated blood while veins carry deoxygenated blood. So now you know more about the human heart and some of the other organs that help it do it’s function. The human heart is a useful organ that doesn’t only fall in love and get broken.