Cardiovascular System Dissection
The cardiovascular system is used to transport oxygen, nutrients, water, and other materials throughout the body. As food is digested in the stomach and broken down into its building blocks, or monomers, these molecules diffuse into the blood stream and are then pumped to all the cells of the body. As oxygen is taken into the lungs, the oxygen diffuses into the blood and is then pumped to all the cells in the body. The blood also transports white blood cells that attack viruses, bacteria, and other foreign substances. They are an essential part of your immune system. The following terms will be important to understand:
Atria - the atria of the heart are the smaller, less muscular upper chambers that collect blood as it returns to the heart. They then contract to pump blood into the ventricles of the heart.
Ventricles - The ventricles of the heart are the lower, larger, more muscular chambers of the heart, which contract to pump the blood out of the heart. In the four-chambered mammalian heart, the left ventricle pumps blood to the bodies tissues, while the right ventricle pumps blood out to the lungs.
Arteries - arteries are vessels that pack blood AWAY from the heart. Most of the arteries pack oxygenated blood out to the body, however the pulmonary artery packs de-oxygenated blood to the lungs. Arteries are thicker, and are surrounded by smooth muscle that allow the arteries to contract or relax to regulate blood pressure.
Capillaries - The arteries branch and get smaller and smaller until finally they reach the capillary beds. Capillaries are tiny blood vessels that are so narrow only a single blood cell can fit through at once. These tiny, thin-walled vessels are the actual sites of oxygen, carbon dioxide, and nutrient exchange. These beds mark the transition between arteries and veins.
Veins - Veins are vessels that pack blood back to the heart. Veins are much thinner and less muscular. Because most of the pressure from the heartbeat is gone by the time blood has gone through the capillary beds, the veins rely mostly on gravity and movement of the muscles to force blood to travel back to the heart. Most veins carry deoxygenated blood, however the pulmonary veins carry oxygenated blood back from the lungs to the heart.
Atria - the atria of the heart are the smaller, less muscular upper chambers that collect blood as it returns to the heart. They then contract to pump blood into the ventricles of the heart.
Ventricles - The ventricles of the heart are the lower, larger, more muscular chambers of the heart, which contract to pump the blood out of the heart. In the four-chambered mammalian heart, the left ventricle pumps blood to the bodies tissues, while the right ventricle pumps blood out to the lungs.
Arteries - arteries are vessels that pack blood AWAY from the heart. Most of the arteries pack oxygenated blood out to the body, however the pulmonary artery packs de-oxygenated blood to the lungs. Arteries are thicker, and are surrounded by smooth muscle that allow the arteries to contract or relax to regulate blood pressure.
Capillaries - The arteries branch and get smaller and smaller until finally they reach the capillary beds. Capillaries are tiny blood vessels that are so narrow only a single blood cell can fit through at once. These tiny, thin-walled vessels are the actual sites of oxygen, carbon dioxide, and nutrient exchange. These beds mark the transition between arteries and veins.
Veins - Veins are vessels that pack blood back to the heart. Veins are much thinner and less muscular. Because most of the pressure from the heartbeat is gone by the time blood has gone through the capillary beds, the veins rely mostly on gravity and movement of the muscles to force blood to travel back to the heart. Most veins carry deoxygenated blood, however the pulmonary veins carry oxygenated blood back from the lungs to the heart.
Anatomy of the Fetal Pig HeartFor this dissection you will need to be able to identify each of the major Arteries and Veins entering or leaving the heart, and explain where they are carrying blood.
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Click here for a simulation showing how blood is pumped through a mammalian heart.
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