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42 Cards in this Set
- Front
- Back
Circulatory system |
The transporting system of the body, consisting of the heart, blood, blood vessels, lymph and lymph vessels |
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Double circulating system |
Blood passes through the heart twice in one completely journ |
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Heart |
Pumps blood around body |
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Heart location |
Middle of chest cavity, between lungs |
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Heart structure |
Made of cardiac muscle which is able to contract and relax regularly Enclosed by pericardium which is a membrane that holds the heart in place and still allows it to beat Has 4 chambers: 2 atria (upper)and 2 ventricles (lower) |
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Atria |
Two upper thin walled chambers of the heart. Receive blood. |
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Ventricles |
Two lower thick walled chambers of the heart. Pump blood. |
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Septum |
Separates left and right chambers so blood cannot mix |
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Valves |
Flaps that are attached to the heart Supported by chordae tendinae Ensures the blood flows in one direction 2 atrio-ventricular valves 2 semi-lunar valves |
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Chordae tendinae |
Fibrous chords supporting valves |
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Atrio-ventricular valves |
Bicuspid valve - between left atria and ventricle Tricuapid valve - between right atria and ventricle |
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Semi-lunar valves |
Aortic - between left ventricle and aorta Pulmonary - between right ventricle and pulmonary artery |
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Vena cava |
Largest vein in the body. Carries deoxygenated blood to the heart from the body |
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Pulmonary artery |
Carries deoxygenated blood to the lungs The only artery to carry deoxygenated blood. |
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Pulmonary vein |
Carries oxygenated blood to the heart The only vein to carry oxygenated blood. |
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Aorta |
Largest artery in the body. Carries oxygenated blood from the heart tk the body. |
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Blood direction |
Heart to arteries to arterioles to capillaries to venules to veins to heart |
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Arteries |
Are elastic, which helps keep the blood moving around the body. Carry oxygenated blood away from the heart. Made of thick muscles and small lumen. Pink in colour (elastic fibres). Located deep within muscle. High pressure, will spurt blood when cut. Do not contain valves. |
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Arterioles |
Small arteries that become narrower the further they get from the arteries. |
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Capillaries |
Smallest blood vessels. Very thin walls so diffusion can take place. Only one layer of cells called the endothelium. Only one RBC at a time, delivers O2 to cells faster. Only permeable blood vessel. |
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Venules |
Small veins. Some larger ones have valves. |
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Veins |
Not elastic. Carry deoxygenated blood to heart. Have thin walls and large lumen. Dark red in colour. Usually found on muscle surface. Lower blood pressure than arteries, blood oozes out when cut. Contain valves. |
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Lumen |
The hollow area in a blood vessel through which blood passes. |
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Heart sounds |
Lubb dubb where lubb is the closing of atrioventricular valves and is short and sharp and dubb the closing of the semilunar valves and is a long muffled sound |
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Murmurs |
Abnormal heart sounds caused by turbulence in the blood flow through the heart and can also indicate a lroblem with the valves. |
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Cardiac cycle |
Atrial systole _ venticular systole _ atrial and ventricular diastole. Takes .8 seconds. Approx 72 beats per min. Own inbuilt rhythm can be increased or decreased by nervous stimulation or chems. |
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Systole |
Pumping phase of the cycle. Heart muscle contracts |
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Diastole |
Filling phase. Heart muscle relaxes. Short time both atria and ventricles are in diastole with the valves open |
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Atrial systole |
Contraction of the atria blood is forced into the ventricles both atria contract together |
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Ventricular systole |
Atria relax and fill with blood as ventricles contract and force blood into arteries both ventricles contract together |
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Blood pressure |
Force exerted by circulating blood on the walls of blood vessels. Decreases further it travels. Arterial pressure is most commonly measured. Written as systolic / diastolic mmHg. Healthy adult is 120/80 mmHg. |
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Systolic arterial pressure |
The peak pressure in the arteries. Occurs near beginning of cardiac cycle. |
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Diastolic arterial pressure |
Lowest pressure at the resting phase of the cardiac cycle |
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Hypertension |
Abnormally high blood pressure |
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Hypotension |
Abnormally low blood pressure |
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Factors influencing blood pressure |
Stress, nutritional factors, obesity, drugs, disease, rate of pumping assuming there is no change in stroke vol., blood volume. |
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Blood transports |
Nutrients, oxygen, carbon dioxide, waste products, hormones. |
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Blood protects against |
Invasion of microorganisms, damage from toxic substances, blood loss. |
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Blood regulates |
Cell water content, pH of body fluids, body temperature. |
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Blood distribution |
Brain and eyes need constant supply Blood flow controlled by vasoconstriction and vasodliation. |
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Vasoconstriction |
Constriction of blood vessels |
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Vasodilation |
Widening of blood vessels. |