What is the largest artery in the body? AortaWhat is the difference between the functions of arteries and veins? Arteries and arterioles distribute blood from the heart to capillaries in all parts of the body; they also help maintain arterial blood pressure by constricting or dilating. Venules and veins collect blood from capillaries and return it to the heart; they also serve as blood reservoirs.Where does the exchange of nutrients and respiratory gases between blood and tissue fluid take place? Capillary bed
Why is the muscle layer thicker in arteries than in veins? The thicker muscle layer is able to resist great pressures generated by ventricular systole. This ability is critical to maintaining blood pressure and controlling blood distribution.What feature is present in veins but not in arteries? ValvesWhat is the function of a precapillary sphincter? It guards the entrance to the capillary and determines how much blood will flow into each capillary bed.What vessels distribute blood from the heart to capillaries? Arteries and arterioles
How do arterioles help keep arterial blood pressure at a normal level? The muscle layer, tunica media, constricts or dilates as necessary.
Why do venules and veins serve as blood reservoirs? Venules and veins carry blood under lower pressure than arteries and can expand to hold a larger volume of blood or constrict to hold a much smaller amount.Why are capillaries known as exchange vessels? Nutrients and gases pass through the capillaries into and out of the cells.What are some of the major arteries? See Figure 14-2 and Table 14-1.
What is the difference between arteriosclerosis and atherosclerosis? Arteriosclerosis is calcification in the arterial walls; atherosclerosis is blockage by lipids and other matter.How do vasodilators treat arteriosclerosis? Vasodilators trigger the smooth muscles of the arterial walls to relax and the arteries to dilate.
What is the danger of an aneurysm? It could burst, causing hemorrhage and death.
What are some nonsurgical methods of treating varicose veins? Avoid standing for long periods, wear support stockings, and rest periodically with legs slightly elevated.What is the danger of thrombophlebitis? Clots can dislodge and become an embolism circulating in the blood.
Is the plan of systemic circulation similar in all tissues and organs? In what parts of the body do capillaries host the exchange of nutrients and respiratory gases? The alveoli
What is the function of liver cells in hepatic portal circulation? Liver cells remove excess glucose after a meal and store it as glycogen; liver cells also remove and detoxify various poisonous substances that may be present in the blood.Why is it important to understand the roles of blood pressure and blood pressure gradient in circulation? The blood pressure gradient is vitally important to keep the blood flowing. If there were no blood pressure gradient between arteries and arterioles, the blood would stop circulation and life would cease.What is the function of pulmonary circulation? Oxygenation of blood and removal of carbon dioxide from the bloodWhat occurs in hepatic portal circulation? Storage of excess glucose as glycogen, detoxification of poisonous substances in the blood
What must happen before the exchange of nutrients and oxygen between fetal and maternal blood can occur? Specialized blood vessels must carry fetal blood to the placenta where exchange occurs and then return it to the fetal body.What is the role of the ductus venosus? It is a continuation of the umbilical vein that serves as a shunt to allow most of the blood returning from the placenta to bypass the immature liver and empty directly into the inferior vena cava.
How is the blood pressure gradient for the entire systemic circulation measured? The mean blood pressure in the aorta (Figure 14-11) is 100 mmHg, and the pressure at the termination of the vena cava is 0. Therefore, with these normal typical figures, the systemic blood pressure gradient is 100 mmHg.Why can high blood pressure become a problem in circulation? If blood pressure becomes too high, it may cause rupture of one or more blood vessels.Why can very low blood pressure become a problem in circulation? If arterial pressure falls low enough, circulation and life would cease. Massive hemorrhage could cause this.
Why is the diameter of the arterioles important? The diameter of the arterioles plays an important role in determining how much blood drains out of arteries into arterioles.What is the relationship between the strength of a heartbeat and blood pressure? The stronger the contraction, the more blood that is pumped, the higher the pressure.What happens if blood is less viscous than normal? Blood pressure decreasesWhat device is used to take blood pressure readings? Sphygmomanometer
What information can the pulse provide about the heartbeat? The pulse provides information about the rate, strength, and rhythmicity of the heartbeat.How many major pulse points are there? here are nine (9) major pulse points. See Figure 14-13.What are pulse points named after?The artery that lies near the surface of the body and over a bone or other firm base.
Give a cause for each of the types of circulatory shock listed.A severe allergic reaction can result in anaphylactic shock. What are some of the symptoms that occur when someone has anaphylactic shock? Symptoms appear rapidly: difficulty in breathing, rapid or weak pulse, nausea and vomiting, rash, wheezing, anxiety, confusion, dizziness, and abdominal cramping.