Time to dissect a sheep heart...
When looking at the front of the heart the left ventricle is the brown area on the right and the right ventricle is the brown area on the left. We are looking at the heart as if it is in a human in front of us. The top of the heart is where all the veins and arteries enter and leave the heart. The right side of the heart receives oxygen poor blood and the left side of the heart distributes oxygen rich blood.
What is the difference between an artery and a vein? An artery carries oxygen rich blood out of the heart to the body. A vein carries oxygen poor blood back to the heart. The only exceptions are the pulmonary arteries that carry oxygen poor blood to the lungs and the pulmonary veins that are filled with oxygen rich blood back to the heart. Just remember that an artery carries blood out and a vein carries blood in.
The superior vena cava carries blood from the upper regions of the body back to the heart, and the inferior vena cava carries the blood from the lower regions of the body to the heart. Also located at the top of the heart is the aorta. This is the major artery that distributes the blood from the heart throughout the body. This is why a cut aorta will lead to death.
The left atrium is the top cavity. Below the left atrium is the mitral, or bicuspid, valve (the white membrane with string like tissue or tendons below it). These tendons connect the membrane to the papillary muscles - they are also referred to as "heartstrings." The mitral valve allows blood to leave the atrium, but not return. |
As seen in the pictures above, the right atrium and ventricle are also separated by a membrane, the atrioventricular valve (AV or tricuspid valve) connected with tendons. These valves between the atria and ventricles control the flow of blood, so when your heart is thumping in your chest, you know the valves are opening and closing quickly - and the atria and ventricles are contracting at a fast rate, pushing the blood from one cavity of the heart in to another. On average, the heart pumps about 2,000 gallons of blood a day! The body recirculates the same 5 quarts of blood through the body three times every minute. For more amazing facts visit Amazing Heart Facts.
To summarize the blood flow through the heart:
Oxygen in blood is used by tissue - blood flows back to the heart through the superior and inferior vena cava - flows through the right atrium, passes through the AV (tricuspid) valve and into the right ventricle - flows through the pulmonary artery into the lungs where the carbon dioxide is removed and the blood is filled with oxygen, becoming oxygen rich - returns to the heart through the pulmonary veins - enter the left atrium, passes through the mitral (bicuspid) valve, enters the left ventricle and passes through the aortic valve - enters the aorta and is sent to the body tissue for the oxygen to be used.
Oxygen in blood is used by tissue - blood flows back to the heart through the superior and inferior vena cava - flows through the right atrium, passes through the AV (tricuspid) valve and into the right ventricle - flows through the pulmonary artery into the lungs where the carbon dioxide is removed and the blood is filled with oxygen, becoming oxygen rich - returns to the heart through the pulmonary veins - enter the left atrium, passes through the mitral (bicuspid) valve, enters the left ventricle and passes through the aortic valve - enters the aorta and is sent to the body tissue for the oxygen to be used.
When you hear of someone needing a valve replaced, you can now picture the mitral (bicuspid) or the AV (tricuspid) valve and if you are watching a TV show and they mention that the aorta was hit with a bullet, you can picture the major artery that carries all the blood from the heart to the different areas of the body.
There's so much more to the heart! Electrical currents created by the heart's natural pacemaker and studies on how the heart can trigger the release of hormones, suggesting that your heart really can create feelings, which is interesting as it relates to scripture. But for now, we hope you enjoyed!