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8 Cards in this Set
- Front
- Back
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Arterioles |
Arterioles play a major role in the regulation of blood pressur. The vasoconstriction and vasodilation regulates blood flow into the capillary bed. Veins contain the most volume of blood when the body is at rest |
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Capillaries |
Capillaries has the thinnest walls |
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The main components of the cardiac conduction system |
The main components of the cardiac conduction system are the SA node, AV node, bundle of His, bundle branches, and Purkinje fibers. An electrical impulse originates in the specialised pacemaker cells of the sinoatrial node (SAN) which sits just above the atria, which have unique electrical properties. >A wave of electrical activity spreads across both left and right atria so they contract together > The electrical impulse converges on another group of cells in between the atria and ventricles, the conduction of the impulse into the ventricles. This allows the atria to contract completely before contraction of the ventricles begins. The electrical impulse then travels down the Bundle of His, conducting fibres which run between the 2 ventricles, towards the apex of the heart. (AVN) which delay |
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The Lub |
The "lub" is the first heart sound, commonly termed S1, and is caused by turbulence caused by the closure of mitral and tricuspid valves at the start of systole. The second sound," dub" or S2, is caused by the closure of aortic and pulmonic valves, marking the end of systole. |
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Blood Flow |
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen- poor blood from the body into the right atrium >As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve. The blood is then pumped through the pulmonary valve via the pulmonary artery to the lungs The blood is then pumped back to the heart via the pulmonary vein into the left atrium The blood is pushed through the mitral valve into the left ventricle From the left ventricle, the blood goes through the aortic valve through the aorta |
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Electrocardiogram |
Electrocardiogram P wave-electrical activity spreads across the atria QRS complex - electrical activity travels through the ventricles T waves electrical activity returns to normal in ventricles |
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Layers of blood vessels |
All arteries and veins contain three layers. The innermost layer is called the tunica intima. The muscular middle layer is called the tunica media, and the outermost layer is called the tunica adventitia. Because capillaries are only one cell layer thick, they only have a tunica intima |
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Types of blood vessels |
There are three kinds of blood vessels Arteries- carries blood away from the heart . Veins- carries blood back to the heart Capillaries-exchanges nutrients and wastes between the blood and tissue. |
