PGY 818 2001: Quiz on hemodynamics and blood flow regulation There are 10 questions each worth one point Questions 6 through 10 are on the back of the page Read all choices carefully, then mark the blue scantron sheet with your choice for each question. 1) The single (as in one) vessel that has the highest resistance to the flow of blood is a (an): a) artery b) arteniole c) capillary d) venule 2) The group of vessels that have the highest resistance to the flow of blood through a tissue are the: a) arteries b) arterioles c) capillaries d) venules 3) Venous vessels have a higher compliance than arteries because, compared to arteries, venous vessels: a) hold more blood volume b) exist in an unstressed volume state c) contain deoxygenated blood d) have a lower blood pressure 4) According to Poiseuille's law, which of the following would have the most pronounced effect on reducing blood flow to a tissue? a) increasing the viscosity of blood by a factor of two b) increasing the average length of arterioles by a factor of two c) decreasing the radius (or diameter) of arterioles by a factor of two d) decreasing the compliance of arterioles by a factor of two 5) If cardiac output were to increase while total peripheral resistance remained unchanged, then capillary blood pressure in the peripheral circulation as a whole would: a) increase b) decrease c) remain unchanged Hemodynamics 2001 6) Dehydration sufficient to decrease plasma volume would result in an increase in: a) b) c) d) hematocrit blood viscosity vascular compliance both (a) and (b) are correct e) both (b) and (c) are correct 7) The rhythmic contraction-relaxation of lymph vessels coupled with valves within lymph vessels allows lymph to: a) b) c) d) be protein free flow against a pressure gradient control plasma colloid osmotic pressure increase interstitial fluid hydrostatic pressure 8) Myogenic autoregulation is weak in patients with atherosclerosis of the legs. As a result arterioles within the legs of these patients have a reduced ability to: a) b) c) d) undergo angiogenesis vasoconstrict in response to an increase in arterial blood pressure form red blood cell aggregates release nitric oxide 9) Which of the following is thought to be a major endothelial derived relaxation factor? a) acetylcholine b) endothelin c) nitric oxide 10) Which of the following is thought to be released from endothelial cells in response to angiotensin II? a) acetylcholine b) endothelin c) nitric oxide PGY 818 2000: Quiz on hemodynamics through blood flow regulation: 1) Which of the following would reduce pressure in the right atrium? a) b) c) d) increasing right ventricular end systolic volume increasing the compliance of venous vessels in the thorax dilation of systemic arterioles decreasing compliance of venous vessels in the legs 2) In which of the following individuals would the viscosity of blood be the highest? a) b) c) d) e) a dehydrated individual an individual with an reduced cardiac output a individual with hypoprotenemia (reduced protein content in the blood) an individual who is a combination of a and b an individual who is a combination of b and c 3) The single (as in only one) vessel that has the highest resistance to blood flow is a (an) ________ whereas, the group of vessels that have the highest resistance to blood flow through a tissue are the a) b) c) d) arteriole - arterioles arteriole - venules capillary - arterioles capillary - capillaries 4) Which of the following would have the greatest effect on increasing blood flow to a tissue, such as skeletal muscle? a) b) c) d) a 20% increase in the number of open capillaries a 20% increase in the diameter of arterioles (i.e., vasodilation) decreasing the viscosity of blood a 20% increase in mean arterial blood pressure 5) When you stand up, venous blood is shifted from the thorax to the abdomen and legs. In spite of a compensatory increase in heart rate, via the baroreflex, cardiac output is depressed. In order for arterial blood pressure to NOT change under these conditions, total peripheral resistance (TPR) must: a) increase b) decrease c) remain unchanged 6) If arterioles within a tissue. such as the gastro-intestinal system, were to dilate, and if systemic arterial blood pressure remained unchanged, then capillary blood pressure within the tissue would: a) increase b) decrease c) remain unchanged Hemodynamic 2000 7) Ischemia (markedly reduced blood flow to a tissue) will elicit: a) b) c) d) activation of angiotensin converting enzyme myogenic vasoconstriction angiogenesis edema 8) Which of the following is a possible factor leading to the dependent rubor and ankle edema seen in Claudication patients? a) b) c) d) inability of endothelial cells to secrete endothelin inablility of endothelial cells to secrete nitric oxide inability of the endothelial cells to secrete angiogenic factors compression of arterial vessels due to cramping of skeletal muscle 9) Medication that inhibits angiotensin converting enzyme (ACE) would result in: a) b) c) d) e) an increase in blood volume a decrease in total peripheral resistance a decrease in the effect of sympathetic activity on blood vessels a, and b and c 10) The increase in tissue blood flow that occurs in response to an increase in metabolic activity of a tissue is: a) b) c) d) an example of active hyperemia an example of reactive hyperemia is mediated by sympathetic neurons acting on alpha receptors is mediated by sympathetic neurons that release acetylcholine PGY818, 1999 Quiz on hemodynamics through blood flow regulation: 10 questions each worth one point 1) Arterial blood pressure is higher than venous pressure because: a) arterial vessels offer less resistance to the flow of blood than do venous vessels b) the volume of blood in the arteries is higher than that in the veins c) at a normal level of blood volume, the compliance of arterial vessels is lower than that of venous vessels d) the arterial system is directly coupled to the left ventricle 2) A 20% increase in which of the following would result in the largest increase in blood flow through a single vessel? (There is nothing magic about 20%, it is just an arbitrary number to make a complete sentence.) a) arterial blood pressure b) venous blood pressure c) length of the vessel d) diameter of the vessel e) viscosity of the blood 3) The capillaries within the circulation of a tissue offer less resistance to blood flow through the tissue compared to the arterioles because: a) capillaries have a smaller diameter compared to arterioles b) there are more capillaries compared to arterioles c) arterioles are regulated by the sympathetic nervous system, whereas capillaries are not d) capillaries have a larger compliance than do arterioles 4) The concentration of globular proteins in plasma increases in response to an infection. In conjunction with this phenomenon, resistance to the flow of blood through a tissue (such as skeletal muscle) is slightly increased because: a) globular proteins elicit vasoconstriction of arterioles b) globular proteins elicit vasoconstriction of venules c) hematocrit increases d) the viscosity of blood increases 5) When you jump into a swimming pool (or lake, or whatever) venous blood is shifted from the abdomen and legs into the thorax resulting in an increase in cardiac output (Starling's Law). In order for arterial blood pressure to NOT change, total peripheral resistance (TPR) must: a) increase b) decrease c) not change 6) After adjustments in TPR in the preceding question, capillary blood pressure would be a) increased b) decreased c) not changed 7) If at the end of a day of standing for long periods of time (e.g., working on an assembly line) a person notices considerable swelling (edema) in their ankles and feet. Otherwis e the cardiovascular systems is normal (e.g., normal arterial blood pressure). That individual is likely to have a) b) c) d) weak myogenic autoregulation of arterioles sclerotic lesions within the arteries of the legs a very low total peripheral vascular resistance elevated viscosity of the blood 8) In which of the following situations would skeletal muscle blood flow be the lowest during rhythmic exercise (e.g., running)? During the a) b) c) d) contraction phase of the muscle in people taking drugs that block beta-2 adrenergic receptors contraction phase of the muscle in people taking drugs that block alpha adrenergic receptors relaxation phase of the muscle in people taking drugs that block beta-2 adrenergic receptors relaxation phase of the muscle in people taking drugs that block alpha adrenergic receptors 1 9) Angiotensin II increases the vasoconstrictor effect of the sympathetic nervous system by a) b) c) d) promoting the release of neuropeptide Y from sympathetic neurons blocking alpha receptors on vascular smooth muscle blocking the uptake of released norepinephrine back into sympathetic neurons promoting myogenic vasoconstriction 10) If you compress an artery with your fingers for about a minute then release the compression, blood flow through the artery will increase above where it was before the compression. This phenomenon is called a) active hyperemia b) reactive hyperemia Hemodynamics 1998 1. a) b) c) d) e) Central venous pressure is lower than systemic arterial pressure because: the baroreceptors are on systemic arteries at normal blood volumes, most venous vessels exist in an unstressed volume state at normal blood volumes, the elasticity of venous vessels is greater than arteries most of the blood volume is on the venous side of the circulatory system intravascular pressure is directly related to the fourth power of the vessel radius 2. Which of the following single or combination of events would result in the largest increase in blood flow through a particular tissue, such as skeletal muscle? a) Increasing mean arterial pressure from 90 to 105 mmHg b) Doubling the diameter of the arterioles c) Doubling the number of capillaries through which blood is flowing d) A combination of A and B e) A combination of B and C 3. With which of the following single or combination of events would the viscosity of blood flowing through tissue to the lowest? Assume blood pressure is the same in all situations. a) A decrease in the concentration of plasma proteins b) A decrease in blood flow through tissue c) An elevation in systemic hematocrit d) A combination of A and B e) A combination of B and C 4. With which of the following single or combination of events would the viscosity of the blood flowing through a tissue to the highest? Assume blood pressure is the same in all situations a) A decrease in the concentration of plasma proteins b) A decrease in blood flow through a tissue c) An elevation in systemic hematocrit d) A combination of A and B e) A combination of B and C 5. The skeletal muscle circulation of a hypertensive patient has adjusted by increasing the resistance to flow of blood through the skeletal muscle by the same degree as systemic arterial pressure has increased. Under this condition, capillary blood pressure within the skeletal muscle circulation would be_________relative to the normotensive state of the patient without any adjustments in the circulation. a) Increased b) Decreased c) Unchanged d) That’s it! There are no other possibilities _ Hemodynamics 1998 6. Pedal edema (edema in the feet and ankles when standing) of a claudication patient is most likely due to: a) vasodilation of the arterioles by autoregulatory mechanisms b) a weakened myogenic response of the arterioles c) failure of the vascular endothelial cells to release EDRF (nitric oxide) d) inhibition of beta adrenergic receptors on vascular smooth muscle 7. In which of the following would skeletal muscle blood flow be the highest during rhythmic exercise (e.g. running)? a) During the contraction phase of the muscle in people taking beta adrenergic blockers b) During the contraction phase of the muscle in people taking alpha adrenergic blockers c) During the relaxation phase of the muscle in people taking beta adrenergic blockers d) During the relaxation phase of the muscle in people taking alpha adrenergic blockers 8. A reduced ability of vascular endothelial cells to secrete paracrines would inhibit: a) red blood cell aggregation b) myogenic vasoconstriction c) flow dependent vasodilation d) both A and B are correct e) both B and C are correct 9. The skeletal muscle circulation distal to a severe atherosclerotic lesion on the supply artery has undergone both acute (short term) and chronic (long term) adjustments in an attempt to maintain resting blood flow near normal. These adjustments most likely include: a) angiogenesis b) metabolic autoregulation c) synthesis of EDCF (endothelin) d) both A and B e) both B and C 10. If vascular smooth muscle cells are deficient in gap junction then: a) none of the cells could respond to the circulating hormones b) the spread of vasoconstriction from cell to cell would be inhibited c) the spread of vasodilation from cell to cell would be inhibited d) both A and B are correct e) both B and C are correct Human Function 1997 Quiz on the Circulatory System 1) Which of the following would be the most effective in reducing the pre -load of the heart in a congestive heart failure patient? A) Vasodilation of arterioles B) Increasing venous compliance C) Reducing arterial compliance D) Increasing heart rate 2) If the diameter of a blood vessel were doubled, then blood flow through the vessel would: A) Increase by 2X B) Increase by I OX C) Increase by 16X D) Decrease by 2X 3) With which of the following would the viscosity of blood flowing through a vessel be the highest ? Assume blood flow and blood pressure conditions are the same in all situations. A) The administration of drugs that inhibit red blood cell aggregation. B) An elevation in plasma protein concentration C) An elevation in hematocrit D) Combination of conditions A and B E) Combination of conditions B and C 4) An increase in the number of tortuous vessels within a tissue will increase vascular resistance by.A) Increasing blood viscosity B) Decreasing vessel diameter C) Increasing geometric hindrance D) Decreasing vessel compliance 5) Failure of arterioles within the feet and ankles to exhibit the myogenic response to an increase in local arterial pressure, as occurs when standing up, could be due to: A) Failure of the vascular endothelial cells to secrete EDRF (nitric oxide) B) Failure of the vascular endothelial cells to secrete EDCF (endothelin) C) Inadequate formation of cyclic GMP within vascular smooth muscle cells D) Excess production of inositol triphosphate within vascular smooth muscle cells 6) Patients taking beta adrenergic receptor blocking agents have a reduced exercise tolerance because: A) The heart rate response to exercise is inhibited B) The stroke volume response to exercise is inhibited C) The muscle blood flow response to exercise is inhibited D) Of a combination of answers A and B E) Of a combination of answers A, B and C 7. Compared to the control state, if you increase the inotropic state of a muscle, it will a) b) c) d) e) shorten more, although the velocity of shortening will decrease for any given loading condition. shorten more, at a more rapid velocity for any given loading condition. no longer have an effective refractory period. experience a decrease in the inward flow of Ca++ during phase I of the action potential. have decreased intracellular levels of Ca++ during systole. 8. If the solid fine represents the control contraction, the broken line in the figure at right mist represent a muscle contraction for which the a) b) c) d) e) preload has decreased. rate of increase in tension/force has decreased. time to peak tension has increased. contractility has increased. inotropism has decreased. 9. In congestive heart failure a) b) c) d) e) the preload on the left/right ventricle will tend to be decreased. the ventricular function curve will be shifted upward and to the left relative to the control curve. the pressure inside the pulmonary capillaries will generally be elevated. pump function may be depressed, but myocardial contractility will be enhanced. the volume of blood inside the ventricle(s) at the end of diastole will be normal or slightly low. 10. Which of the following statements is correct? a) b) c) d) e) During systole atrial pressure and aortic pressure will be nearly identical. During isovolumic contraction the AV valve is open and the aortic valve is closed. At the moment ejection begins the pulmonary valve closes. The rate of ejection of blood is more rapid early in systole than later in systole. The T-wave is caused by the relaxation of ventricular muscle.