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97 Cards in this Set
- Front
- Back
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What is the functional value of having capillaries that consist of a single layer of squamous cells underlain by sparse connective tissue?
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Capillaries are the exchange sites. The thinner their walls (the barrier to exchanges), the more rapid and efficient the exchange process.
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Which contains more blood, the systemic or pulmonary circulation? In the systemic circulation, which contains more blood, arteries, or veins?
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The systemic circulation contains more blood and most of that blood is in the veins.
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Which condition (sphincters open or closed) would a capillary bed be in if you were doing calf raises at the gym?
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Sphincters open: The true capillaries would be flushed with blood to ensure that the working calf muscles could receive the needed nutrients and dispose of their metabolic wastes.
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In which class of blood vessels does the greatest drop in blood pressure occur?
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Arterioles, because this is the site of greatest resistance. Arterioles control the distribution of blood to the tissues by changing their resistance.
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Why is blood delivery to the skin vasculature increased during strenuous exercise?
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Muscle activity generates heat, which must be dissapated if homestasis is to be maintained. The skin is the body's heat exchange site.
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Suppose you were in a bicycle race. What would happen to the smooth muscle in the arterioles supplying your quadriceps femoris muscle? What are the key mechanisms in this case?
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Intrinsic metabolic controls cause arterioles smooth muscle to relax, dilating the vessels and supplying more O2 and nutrients. Epinephrines from the adrenal medulla may reinforce these mechanisms via B2 receptors.
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How would fluid flows change if the OP of the interstitial fluid rose dramatically - say because of a severe bacterial infection in the surrounding tissues?
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Fluid that would ordinarily reenter the circulation at the venous end of the capillary bed would remain in the tissue spaces, held by the elevated OP of the interstitial fluid.
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Which statement does not accurately describe veins?
A) They have less elastic tissue and smooth muscle than arterioles B) They contain more fibrous tissue than arteries C) Most veins in the extremities have valves D) They always carry deoxygenated blood |
D) They always carry deoxygenated blood
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Smooth muscle in the blood vessel wall:
A) Is found primarily in the tunica intima B) Is mostly circularly arranged C) Is most abundant in veins D) Is usually innervated by the parasympathetic nervous system |
B) Is mostly circularly arranged
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Peripheral resistance:
A) Is inversely proportional to the length of the vascular bed B) Increases in anemia C) Is decreased in obesity D) Is inversely related to the diameter of the arterioles |
D) Is inversely related to the diameter of the arterioles
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Which of the following can lead to decreased venous return of blood to the heart?
A) An increase in blood volume B) An increase in venous pressure C) Damage to the venous valves D) Increased muscular activity |
C) Damage to the venous valves
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Arterial blood pressure increases in response to:
A) Increasing stroke volume B) Increasing heart rate C) Arteriosclerosis D) Rising blood volume E) All of these |
C) Arteriosclerosis
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Which of the following would not result in the dilation of the feeder arterioles and opening of the precapillary sphincters in systemic capillary beds?
A) A decrease in local tissue O2 content B) An increase in local tissue CO2 C) A local increase in histamine D) A local increase in pH |
D) A local increase in pH
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The structure of a capillary wall differs from that of a vein or artery because:
A) It has two tunics instead of three B) There is less smooth muscle C) It has a single tunic - only the tunica intima D) None of these |
C) It has a single tunic - only the tunica intima
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The baroreceptors in the carotid sinus and aortic arch are sensitive to:
A) A decrease in CO2 B) Changes in arterial pressure C) A decrease in O2 D) All of these |
B) Changes in arterial pressure
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The myocardium receives its blood supply directly from:
A) The aorta B) The coronary arteries C) The coronary sinus D) The pulmonary arteries |
B) The coronary arteries
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Blood flow in the capillaries is steady despite the rhythmic pumping of the heart because of the:
A) Elasticity of these large arteries B) Small diameter of capillaries C) Thin walls of the veins D) Venous valves |
A) Elasticity of these large arteries
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Tracing the blood from the heart to the right hand, we find that blood leaves the heart and passes through the aorta, the right subclavian artery, the axillary and bracial arteries, and through either the radial or ulnar artery to arrive at the hand. Which artery is missing from the sequence?
A) Coronary B) Brachiocephalic C) Cephalic D) Right common carotid |
B) Brachiocephalic
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Which of the following do not drain directly into the inferior vena cava?
A) Inferior phrenic veins B) Hepatic veins C) Inferior mesenteric vein D) Renal veins |
C) Inferior mesenteric vein
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In atherosclerosis, which layer of the vessel wall thickens most?
A) Tunica media B) Tunica intima C) Tunica adventitia D) Tunica externa |
B) Tunica intima
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Suppose that at a given point along a capillary, the following forces exist: capillary hydrostatic pressure (HPc) = 30 mm Hg, interstitial fluid hydrostatic perssure (HPif) =0 mm Hg, capillary colloid osmotic pressure (OPc) - 25 mm Hg and interstitial fluid colloid osmotic pressuer (OPif) = 2 mm Hg. The net filtration pressure at this point in the capillary is:
A) 3mm Hg B) -3mm Hg C) -7mm Hg D) 7mm Hg |
D) 7mm Hg
Net Filtration Pressure = (HPc - HPif) - (OPc - OPif) |
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Using the letters from column B, match the artery descriptoins in column A. (Note that some require more than a single choice)
(1) unpaired branch of abdominal aorta (2) second branch of aortic arch (3) branch of internal carotid (4) branch of external carotid (5) origin of femoral arteries (a) right common carotid (b) superior mesenteric (c) left common carotid (d) external iliac (e) inferior mesenteric (f) superficial temporal (g) celiac trunk (h) facial (i) opthalmic (j) internal iliac |
1) b, e, g
2) c 3) i 4) f, h 5) d |
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What are the respective functions of arteries, veins, and capillaries?
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Blood is transported throughout the body via a continuous system of blood vessels. Arteries transport blood away from the heart, veins carry blood back to the heart. Capillaries carry blood to tissue cells and are exchange sites.
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What are the layers composing the walls of blood vessels and capillaries?
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All blood vessels except capillaries have three layers: tunica intima, tunica media, and tunica externa. Capillary walls are composed of the tunica intima only.
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How do elastic and muscular arteries differ? What is the function of arterioles? Describe arteriosclerosis and atherosclerosis; what are the differences between the diseases?
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Elastic (conducting) arteries are the large arteries close to the heart that expand during systole, acting as pressure reservoirs, and then recoil during diastole to keep blood moving. Muscular (distributing) arteries carry blood to specific organs; they are less stretchy and more active in vaso-constriction. Arterioles regulate blood flow into capillary beds.
Arteriosclerosis is a degenerative vascular disease that decreases the elasticity of arteries. Atherosclerosis is the formation of fatty subendothelial lesions. |
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Describe the structure of capillaries. How permeable are the three types? What is the purpose of vascular shunts? How is the amount of blood flowing into true capillaries regulated?
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Capillaries are microscopic vessels with very thin walls. Most exhibit clefts, which aid in the exchange between the blood and interstitial fluid.
The most permeable capillaries are sinusoids [wide, tortuous channels]. Fenestrated capillaries with pores are next most permeable. Least permeable are continuous capillaries, which lack pores. Vascular shunts [metarteriole-thoroughfare channels] connect the terminal arteriole and venule at opposite ends of a capillary bed. Most true capillaries arise from and rejoin the shunt channels. The amount of blood flowing into the true capillaries is regulated by precapillary sphincters. |
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How does the structure of veins differ from arteries?
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Veins have comparatively larger lumens than arteries, and a system of valves prevents backflow of blood.
Normally most veins are only partially filled, thus, they can serve as blood reservoirs. |
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Define an anastomosis.
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The joining together of arteries to provide alternate channels for blood to reach the same organ is called an anastomosis. Vascular anastomeoses also form between veins and between arterioles and venules.
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Describe the relationships between blood flow, blood pressure, and resistance.
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Blood flow is the amount of blood flowing through a vessel, an organ, or the entire circulation in a given period of time. Blood pressure is the force per unit area exerted on a vessel wall by the contained blood. Resistance is opposition to blood flow; blood viscosity and blood vessel length and diameter contribute to resistance.
Blood flow is directly proportional to blood pressure and inversely proportional to resistance. |
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When are systolic and diastolic pressure measured in the circulatory cycle.
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Systemic blood pressure is highest in the aorta and lowest in the venae cavae. The steepest drop in BP occurs in the arterioles, where resistance is greatest.
Arterial BP depends on compliance of the elastic arteries and on how much blood is forced into them. Arterial blood pressure is pulsatile, and peaks during systole; this is measured as systolic pressure. During diastole, as blood is forced distally in the circulation by the rebound of elastic arteries, arterial BP drops to its lowest value, called the diastolic pressure. |
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How is pulse pressure calculated? How is mean arterial pressure calculated? What is the pressure range found in low capillary pressure and venous pressure?
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Pulse pressure is systolic pressure minus diastolic pressure. The mean arterial pressure [MAP] = diastolic pressure plus one-third of pulse pressure and is the pressure that keeps blood moving throughout the cardiac cycle.
Low capillary pressure [35 to 15 mm Hg] protects the delicate capillaries from rupture while still allowing adequate exchange across the capillary walls. Venous pressure is nonpulsatile and low [declining to zero] because of the cumulative effects of resistance. Venous valves, large lumens, functional adaptations [muscular and respiratory pumps], and sympathetic nervous sytesm activity promote venous return. |
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How does blood pressure relate to cardiac output? How does vessel diameter affect this?
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Blood pressure varies directly with CO, peripheral resistance [R], and blood volume. Vessel diameter is the major factor determining resistance, and small changes in vessel [chiefly arteriolar] diameter significantly affect blood pressure.
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How is blood pressure regulated?
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BP is regulated by autonomic neural reflexes involving baroreceptors or chemoreceptors, the vasomotor center [a meduallary center that regulates blood vessel diameter], and sympathetic vasomotor fibers, which act on vascular smooth muscle.
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What is the chain of events followed by the vasomotor center when activating the cardioacceleratory center?
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Activation of the receptors by falling BP (and to a lesser extent by a rise in blood CO2, or falling blood PH or 02 levels) stimulates the vasomotor center to increase vasoconstriction and the cardioacceleratory center to increase heart rate and contractility. Rising BP inhibits the vasomotor center (permitting vasodilation) and activates the cardioinhibitory center.
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How do higher brain centers control BP?
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Higher brain centers (cerebrum and hypothalamus) may modify neural controls of BP via medullary centers.
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What are the effects of hormones on blood pressure?
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Hormones that increase BP by promoting vasoconstriciton include epinephrine and NE (these also increase heart rate and contractility), ADH, and angiotensin II (generated in response to renin release by kidney cells). Hormones that reduce BP by promoting vasodilation include atrial natriuretic peptide, which also causes a decline in blood volume.
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Describe the renin-angiotensis mechanism.
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Indirect renal regulation of blood volume involves the renin-angiotensis mechanism, a hormonal mechanism. When BP falls, the kidneys release renin, wihch triggers the formation of angiotensin II (a vasoconstrictor) and release of aldosterone, which causes salt and water retention.
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How is cardiovascular efficiency measured?
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Pulse and blood pressure measurements are used to assess cardiovascular efficiency.
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What events do a pulse represent?
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The pulse is the alternating expansion and recoil of arterial walls with each heartbeat. Pulse points are also pressure points.
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How is blood pressure measured? What are hypotension and hypertension, respectively?
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Blood pressure is routinely measured by the auscultatory method. Normal blood pressure in adults is 120/80 (systolic/diastolic). Hypotension is rarely a problem. Hypertension is the major cause of myocardial infarct, stroke, and renal disease.
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What does hypotension signify?
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Hypotension, or low blood pressure (systolic pressure below 100 mm Hg), is a sigh of health in the well condiditioned. In other individuals it warns of poor nutrition, disease, or circulatory shock.
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What does hypertension signify?
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Chronic hypertension (high blood pressure) is persistent BP readings of 140/90 or higher. It indicates increased peripheral resistance, which strains the heart and promotes vascular complications of other organs, particularly the eyes and kidneys. Risk factors are high-fat, high salt diet, obeisity, diabetes mellitus, advanced age, smoking, stress, and being a member of the black race or a family with a history of hypertension.
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What functions are served by blood flow?
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Blood flow is involved in delivering nutrients and wastes to and from cells, gas exchange, absorbing nutrients, and forming urine.
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What areas of the body have the fastest and slowest blood flow, respectively? What does the change in blood flow rate support?
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Blood flows fastest where the cross-sectinoal area of the vascular bed is least (aorta) and slowest where the total cross-sectional area is greatest (capillaries). The slow flow in capillaries allows time for nutrient-waste exchanges.
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Describe autoregulation.
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Autoregulation is the local adjustment of blood flow to individual organs based on their immediate requirements. It involves myogenic controls that maintain flow despire changes in blood pressure, and local chemical factors. Vasodilators include increased CO2, H+, and nitric oxide. Decreased O2, and nutrient concentrations also cause vasodilation. Other factors, including endothelins, decrease blood flow.
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How is autoregulation controlled?
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In most instances, autoregulation is controlled by oxygen deficits and accumulation of local metabolites. However, autoregulation in the brian is controlled primarily by a drop in pH and by myogenic mechanisms; and vasodilation of pulmonary circuit levels occurs in response to high levels of oxygen.
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How are various substances transported through capillary walls?
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Nutrients, gases, and other solutes smaller than plasma proteins cross the capillary wall by diffusion. Water-soluable substances move through the clefts or fenestrations; fat-soluable substances pass through the lipid portion of the endothelial cell membrane; larger molecules are actively transported via pinocytotic vesicles or caveolae.
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How is the distribution of fluids between the bloodstream and the interstitial space?
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Bulk flow of fluids at capillary beds determines the distribution of fluids between the bloodstream and the interstitial space. It reflects the relative effect of outward (net hydrostatic pressure) forces minus the effect of inward (net osmotic pressure) forces. In general, fluid flows out of the capillary bed at the arterial end and reenters the capillary blood at the venule end.
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How is fluid lost into interstitial space recovered?
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The small net loss of fluid and protein into the interstitial space is collected by lymphatic vessels and returned to the cardiovascular system.
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What are the physical causes of shock?
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Circulatory shock occurs when blood perfusion of body tissues is inadequate. Most cases of shock reflect low blood volume (hypovolemic shock), abnormal vasodilation (vascular shock), or pump failure (cardiogenic shock)
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Describe the function of the pulmonary circuit
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The pulmonary circulation transports O2-poor, Co2-laden blood to the lungs for oxygenation and carbon dioxide unloading. Blood returning to the right atrium of the heart is pumped by the right ventricle to the lungs via the pulmonary trunk. Blood issuing from the lungs is returned to the left atrium by the pulmonary veins.
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Describe the function of the systemic circuit
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The systemic circulation transports oxygenated blood from the left ventricle to all body tissues via the aorta and its branches. Venous blood returning form the systemic circuit is delivered to the right atrium via the venae cavae.
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Where do arteries lie within the body?
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All arteries are both deep and superficial. Superficial veins tend to have numerous interconnections. Dural sinuses and the hepatic portal circulation are unique venous drainage patterns.
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What does vasculature arise from in the fetus? When does it first begin functioning?
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The fetal vasculature develops from embryonic blood islands and mesenchyme and is functioning in blood delivery by the fourth week.
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How does fetal circulation differ from adult circulation?
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Fetal circulation differese form circulation after birth. The pulmonary and hepatic shunts and special umbilical vessels are normally occluded shortly after birth.
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What age-related issues affect blood pressure?
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Blood pressure is low in infants and rises to adult values. Age-related vascular problems include varicose veins, hypertension, and atherosclerosis. Hypertension is the most important cause of sudden cardiovascular death in middle-aged men. Atherosclerosis is the most important cause of cardiovascular disease in the aged.
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What theory of blood movement was proposed by the greek physician Galen? Whose theory superseeded it in 1620?
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Galen proposed that blood moved through the body like an ocean tide, first moving out from the heart and then ebbing back int he same vessels. In 1620, William Harvey, an English physician, postulated that blood circulated throughout the body.
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How long would the blood vessels in an adult human be, if put end to end?
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approximately 100, 000 km (60,000 miles)
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What is the most distinguishing feature of an arteriole?
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Arteriole – the distinguishing feature of this vessel is the tunica media is composed of a single layer of smooth muscle tissue
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What two types of vessels are found in the capillary bed?
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Within the capillary bed are two types of vessels:
- Vascular shunt (thoroughfare channel) - True capillaries (metabolic exchange |
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How is blood flow defined? In what units is it measured?
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Blood flow is defined as the volume of blood flowing through a vessel, organ, or system in a given time period, is measured in milliliters per minute (ml/min)
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During conditions of high stress (fight or flight), what happens to blood supply routing?
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During conditions of stress similar to the “fight-or-flight” scenario, the
ANS will re-route blood flow from non-essential organs. This re-routed blood can serve skeletal muscle while the constricted arterioles contribute towards increased arterial pressure. |
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What does the cardiovascular center within the medulla oblongata regulate?
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The cardiovascular center located within medulla oblongata regulates:
- Heart rate - Strength of contractions - Blood vessel diameter (BP) |
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Where are baroreceptors located? What are they sensitive to?
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Baroreceptors located within the carotid sinus and aortic arch is sensitive to stretch; are
activated by elevations in BP, which is related to cardiac output (HR x SV). Excessive stretch is detected by the baroreceptors and is relayed by the glossopharyngeal nerve (IX) and vagus nerve (X) towards the medulla. The cardiovascular center (integration) responds by activating the cardioinhibitory center and vasomotor center which generate a motor response. |
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What are the functions served by the cardioinhibitory and vasomotor centers?
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The cardioinhibitory center and the vasomotor center will:
- Reduce heart rate - Reduce the strength of ventricular contraction - Increases arteriole diameter |
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Where are chemoreceptors located? What is their function?
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Chemoreceptors located with the carotid sinus and wall of the aortic arch, respond to changes
in blood chemistry. Elevated CO2 levels, low pH and low O2 levels in blood stimulate these receptors which transmits impulses via cranial nerves IX and X to the cardioacceleratory center within the medulla. The stimulation of the cardioacceleratory center will increases blood flow by increasing cardiac output in the attempt to remove accumulated metabolic waste products (CO2 and H+ ) from the blood, primarily relying on the respiratory system to expel excess CO2 and bring in needed O2. |
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How is ANP release triggered? What is it's function?
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Atrial Natriuretic Peptide (ANP) – atria walls respond to excessive stretch.
An increase in blood volume within chamber results in an increase in BP, the triggers the release of ANP. ANP target the kidney, increases the excretion of sodium ions and water (blood plasma 90% water). By decreasing blood volume through the elimination of sodium ions and water, BP will drop. |
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What two chemicals are released by the adrenal medulla during periods of stress?
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Adrenal Medulla under period of stress will release:
- Norepinephrine is vasoconstrictor (increased peripheral resistance) - Epinephrine increases cardiac output (blood pressure related to blood flow) |
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How do the direct and indirect methods of renal regulation work?
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Long term controls maintain blood pressure by altering blood volume; this involves two methods which operate on the permeability of the renal tubules located in the kidney.
- Direct renal mechanism – as blood volume increases or blood pressure rises, more blood is filtered and enters into the renal tubules. Because of the increased blood volume and increased pressures, the newly formed filtrate cannot be reabsorbed fast enough; water is lost during the process of urine formation. Losing excess water from the blood will reduce blood volume and lower BP. - Indirect renal mechanism – involves the renin-angiotensin pathway. This ultimately results in an increase in the re-absorption of sodium ions and water within the kidney. The addition of sodium ions within the blood plasma will attacked water within the renal tubule. This results in an increase in blood volume and blood pressure. |
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Which of the following statements is true?
A) Capillaries normally function best under high pressures B) The thick walls of capillaries enhance the process of diffusino and osmosis C) Blood flow within the tissues is proportional to the metabolic needs of the cell D) The continuous capillary is the "leakiest" of all capillaries |
C) Blood flow within the tissues is proportional to the metabolic needs of the cell
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Which of the following molecules is not considered a vasodilator substance?
A) Lactic acid B) Carbon dioxide C) Oxygen D) Adenosine diphosphate (ADP) |
C) Oxygen
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Excess interstitial fluid with the tissue beds is removed by:
A) Passive events associated with osmosis B) The processes of selective secretion and filtration C) The surrounding lymphatic capillaries of the lymphatic system D) The contraction of skeletal muscle tissue |
C) The surrounding lymphatic capillaries of the lymphatic system
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Blood pressure at the arteriole end of the capillary is measured as:
A) 80 mm Hg B) 65 mm Hg C) 32 mm Hg D) 15 mm Hg |
C) 32 mm Hg
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Along the venous end of the capillary, fluid within the interstitial space returns to the capillary by:
A) Active transport across the endothelial membrane B) Increased hydrostatic pressure within the capillary C) The colloid osmotic pressure generated by non-permeable proteins D) The high hydrostatic pressue within the interstitial compartment |
C) The colloid osmotic pressure generated by non-permeable proteins
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In general, an increase in blood volume will result in:
A) An increase in blood pressure B) A decrease in urine production C) A decrease in heart rate D) Normal heart dynamics; no variations in heart rate or stroke volume |
A) An increase in blood pressure
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Which of the following represents a long-term mechanism for maintaining blood pressure (BP)?
A) The renin-angiotensin pathway B) Atrial natriuretic peptide C) Norepinephrine released from the adrenal medulla D) Elevated pCO2 levels |
A) The renin-angiotensin pathway
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The vasomotor center will send sympathetic motor neurons which innervate
A) The smooth muscles of arterioles B) The tunica media of muscular arteries C) Elastic arteries D) Capillary bed |
B) The tunica media of muscular arteries
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Changes in blood chemistry such as pH, pO2, and pCO2 are detected by:
A) Chemoreceptors B) Baroreceptors C) Nociceptors D) Afferent neurons |
A) Chemoreceptors
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Baroreceptors are located within
A) The carotid sinus B) The walls of atria C) The vaomotor center D) The cardioacceleratory center |
A) The carotid sinus
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Besides the vagus nerve (X), which other cranial nerve carries sensory impulses form the carotid bodies?
A) Hypoglossal nerve (XII) B) Glossopharyngeal nerve (IX) C) Trigeminal nerve (V) D) Accessory nerve (XI) |
B) Glossopharyngeal nerve
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The larger the lumen (diameter) of the blood vessel:
A) There is an increase in turbulent blood flow B) The lower the peripheral resistance (BP) C) The greater the blood pressure D) Blood pressure remains constant |
B) The lower the peripheral resistance (BP)
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Which of the following best describes systolic blood pressure?
A) The maximum contractile force generated by the atria B) The force upon arterial walls during peak ventricular contraction C) The pressure generated from end systolic volume D) The pressure within the aorta (80 mm Hg) prior to ventricular contraction |
B) The force upon arterial walls during peak ventricular contraction
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Which of the following does not contribute to an increase in peripheral resistance?
A) Blood vessel length B) Blood vessel diameter C) State of dehydration D) Average numbers of RBCs |
B) Blood vessel diameter
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The consequences of turbulent blood flow includes all, except:
A) Increased friction between blood and vessel walls B) Continuous laminar blood flow C) Increases in blood pressure D) Greater contractile force to propel blood through vessels |
B) Continuous laminar blood flow
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The site of metabolic exchange occurs within the:
A) Capillaries B) Elastic arteries C) Arterioles D) Muscular arteries |
A) Capillaries
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The endothelium of blood vessels is composed of:
A) Epithelial tissue B) Smooth muscle tissue C) Connective tissue D) Elastic tissue |
A) Epithelial tissue
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The fibers of the autonomic nervous system will innervate the:
A) Tunica interna B) Tunica media C) Tunica externa D) Tunica intima |
B) Tunica media
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Those blood vessels which can function as a "secondary pump" are:
A) Continuous capillaries B) Elastic arteries C) Arterioles D) Muscular arteries |
B) Elastic arteries
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Blood travels through low pressure vessels by:
A) The isovolumetric contraction of the ventricles B) The gravitational pull generated by planetary alignment C) The contraction of surrounding skeletal muscle tissue D) The interstitial fluid pressure of the capillary bed |
C) The contraction of the surrounding skeletal muscle tissue
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This type of capillary is commonly found in areas of high filtration or absorption:
A) Continuous B) Discontinuous C) Fenestrated D) Sinusoid |
C) Fenestrated
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The contraction of the pre-capillary sphincter will:
A) Increase blood flow to the tissue bed B) Re-distribute blood flow within muscular arteries C) Decrease blood pressure D) By-pass the tissue bed and increase venous return |
D) By-pass the tissue bed and increase venous return
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The opposition to blood flow is called:
A) Turbulence B) Laminar blood flow C) Compliance D) Resistance |
D) Resistance
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The larger the lumen (diameter) of the blood vessel:
A) The lower the peripheral resistance (BP) B) The greater the blood pressure C) Blood pressure remains constant D) There is an increase in turbulent blood flow |
A) The lower the peripheral resistance (BP)
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An increase in blood viscosity may result from:
A) Hydration B) Hyperventillation C) Dehydration D) Starvation |
C) Dehydration
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Force per unit area measured in millimeter mercury best describes:
A) Cardiac output B) Peripheral resistance C) End diastolic volume D) Blood pressure |
D) Blood pressure
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Which of the following does not contribute to an increase in peripheral resistance?
A) Blood vessel length B) State of dehydration C) Blood vessel diameter D) Average numbers of RBC's |
C) Blood vessel diameter
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Which of the following is not typical of a low pressure vessel?
A) Thick muscle walls B) Large lumens C) Endothelial valves D) Blood pressure ranging between 20-0 mm Hg |
A) Thick muscle walls
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