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14 Cards in this Set
- Front
- Back
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Describe the 3 tunics making up the wall of anartery. Why is the tunica media particularly important?
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Tunica Externa, Tunica Media, Tunica Intima. Tunica Media is particularly important because it contracts to vasodilate or vasocontrict the vessel |
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Which tissue layer is continuous throughout theentire cardiovascular system?
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Tunica Intima |
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In what ways are capillaries especially wellfitted for their function as part of the system where the actual work of theblood is done?
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They only contain tunica intima which allows for rapid exchange of gas & nutrients |
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Why are valves necessary in veins? What are varicoseveins? What factors are involved in the return of blood to the heart?
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They prevent backflow of blood. In varicose veins, the valves aren't functioning properly and blood is pooling in the veins. The skeletal pump that contracts the muscle to help push blood up veins in the limbs & the respiratory pump which helps move the blood from the abdominal cavity to the thoracic cavity. |
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Where is the majority of blood in thecirculatory at any one given time? Whichvessels are under the greatest pressure? Which vessels generally have the greatest diameter? Which vessels havethe greatest cross-sectional area? |
In the veins. The arteries are under greatest pressure. The veins have the greatest diameter. Capillaries have the greatest cross-sectional area (allows for the slow down of blood for proper nutrient & gas exchange) |
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Which vessels are resistant vessels? Exchangevessels? Reservoirs?
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Arteries are resistant vessels. Capillaries are exchange vessels. Veins are reservoirs. |
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What is the principle mechanism by means ofwhich substances are exchanged between capillary blood and body cells? What isNet Filtration? How is it calculated? What is BHP?What is IHP? What is colloidalpressure?
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Filtration and Reabsorption. Net filtration is the difference between Net hydrostatic pressure and Net colloid osmotic pressure. Net Fil = (BHPh-BHPif) - (BCOPh-BCOPif) i.e. (32 mm HG- 0 mm HG) - (22 mm HG - 5 mm HG) Blood Hydrostatic Pressure: the force exerted on wall by blood, promotes filtration in capillary Interstitial Fluid Hydrostatic Pressure: force of interstitial fluid on external wall of blood vessel (normally close to 0) Colloidal pressure: draws fluid into vessel due to blood proteins -- promotes reabsorption -- opposes hydrostatic pressure. |
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What opposing pressures determine the directionof flow of fluids between interstitial fluid and blood plasma in thecapillaries? Where in the capillary doesfiltration occur? Where does reabsorption occur?
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Blood hydrostatic pressure and Blood Colloidal Osmotic Pressure. Filtration occurs at the arteriole end. Reabsorption occurs at the venule end. |
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What force causes blood to flow? In whichvessels will blood flow fastest? Slowest?
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The heart causes blood to flow. It will flow the fastest in arteries and the slowest in capillaries. |
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What terms define blood pressure? What is beingmeasured? How is this different from pulse pressure and pulse rate? What is the norm BP?
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Blood pressure is the force exerted against the bloodvessel wall. Pulse pressure is the additional pressure put on the arteries whenthe heart is contracting. It is the difference between Systolic pressure andDiastolic Pressure. Normal BP is 120/80
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What causes a pulse? What is Tachycardia? Whatis Bradycardia? What is MAP? What isaverage MAP? If MAP drops below 50mmHg what happens?
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Pulse pressure causes throbbing sensation. Tachycardia is abnormally rapid heart rate. Bradycardia is abnormally slow heart rate. Mean Arterial Pressure is the average blood pressure force on the arteries. Average MAP is about 90 mm HG. If it drops below 50 there will be insufficient blood flow in the body. Organs may not be able to function properly. |
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What is resistance? What are factors thatincrease blood resistance? Which factor is the major determinant of resistance?Which factors generally do not change daily?
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Amount of friction blood experience traveling through the vessels. Vessel length, diameter, and viscosity. Diameter is the major determinant of resistance. Vessel length does not change daily. |
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How areblood volume, and blood pressure related? What is hypertension?
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Blood volume and blood pressure are directly related. Increase in volume means increase in pressure. Hypertension is an abnormally high blood pressure. |
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What is vasoconstriction? What isvasodilatation?
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Vasoconstriction is a decrease in vessel diameter. Vasodilation is an increase in vessel diameter. |
