A&P II: Chapter 18 – Flashcards
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What type of vessel is capable of allowing the passage of gases and nutrients though its walls to nourish surrounding tissue?
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Capillaries
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What type of vessel has a relatively large amount of smooth muscle compared to its elastic tissue?
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Muscular Arteries
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Which type of vessel is most suited to expanding and recoiling in response to the ejection of blood from the heart?
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Elastic Artery
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Which layer of the typical vessel can be regulated to constrict or dilate the lumen?
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Tunica Media
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Arteries always carry oxygenated blood away from the heart.
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False. (Arteries always carry blood away from the heart. However, blood in the pulmonary circuit is the opposite of what we might expect. Blood carried away from the heart and to the lungs is deoxygenate)
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Large diameter, thick-walled arteries that are close to the heart and act as pressure reservoirs would be __________.
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Elastic Arteries
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Which of the following would NOT move by diffusion across a capillary endothelium to or from the surrounding interstitial fluid and tissues?
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Proteins
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Which of the following is NOT a capillary transport mechanism?
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Bulk Flow
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The most permeable capillaries, which contain fenestrations and large intercellular clefts, are __________.
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Sinusoid Capillaries
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The kidneys filter the blood; it is necessary for plasma, both fluid and dissolved chemicals, to be rapidly removed from the blood without the removal of larger proteins or cells. Which capillary would be best suited for this filtration?
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Fenestrated Capillaries (These permeable vessels have continuous walls between endothelial cells, but the cells have numerous pores and are found in the kidneys, lining the small intestine, and in other areas.)
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Varicose veins seen in the superficial veins of the legs are unsightly and often treated by surgically removing them. However, even without these veins being present, the return of all blood toward the heart from the legs is not diminished primarily because ______.
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blood can still return via the deep veins
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Which vessels carry blood toward the heart?
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Veins
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Which of the following is characteristic of veins but not arteries?
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Large internal diameter
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Which of the following would decrease peripheral resistance to blood flow?
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Anemia
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Which of the following is NOT correct regarding the relationship between pressure, flow, and resistance in the cardiovascular system?
A: Blood flow is inversely proportional to the change in pressure in the blood vessels.
B: Blood flow equals cardiac output.
C: The relationship between resistance and flow is the opposite of the relationship between pressure and flow.
D: Instead of resistance affecting systemic circulation, most of the time resistance is used to change flow to individual organs.
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A. Blood flow is inversely proportional to the change in pressure in the blood vessels.
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Which of the following is NOT an important source of resistance to blood flow?
total blood volume
vessel length
vessel diameter
blood viscosity
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total blood volume
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At what point would we definitely NOT be able to measure the difference between systolic, diastolic, and mean arterial pressure?
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Capillaries
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Which of these responses is NOT a response consistent with a drop in mean arterial pressure?
increased thirst
secretion of aldosterone
increased filtration by the kidneys
release of renin from the kidneys
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Increased filtration by the kidneys.
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Which of the following would be interrupted in the indirect renal mechanism if angiotensin converting enzyme (ACE) is blocked from performing its job?
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conversion of angiotensin I into angiotensin II (Angiotensin converting enzyme (ACE) produced in the lungs and other tissues converts circulating angiotensin I to angiotensin II.)
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Which of the following will lower blood pressure?
atrial natriuretic peptide (ANP)
antidiuretic hormone (ADH)
aldosterone
angiotensin II
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ANP - atrial natriuretic peptide (Atrial natriuretic peptide (ANP) is a hormone released by the heart. It stimulates the kidney to excrete more sodium and water, which decreases total blood volume, leading to a reduction in blood pressure.)
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Which of the following is involved in long-term regulation of blood pressure?
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Renal Mechanisms ( Long-term control of blood pressure is achieved through direct and indirect renal control mechanisms.)
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Decreased output from the vasomotor center allows arterioles and veins to constrict. (true or false)
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False. (Decreased output from the vasomotor center allows arterioles and veins to dilate.)
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Which of the following hormonal effects is mismatched?
Angiotensin increases peripheral resistance by causing vessel diameter changes.
Epinephrine decreases peripheral resistance by blood vessel diameter.
Aldosterone increases blood pressure by affecting blood volume.
Atrial natriuretic protein decreases blood volume by affecting blood vessel diameter.
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Epinephrine decreases peripheral resistance by blood vessel diameter. (Epinephrine increases peripheral resistance by causing vasoconstriction)
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Vasomotion because of changes in pH or CO2 levels would be a result of __________?
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Chemoreceptor reflexes (Chemoreceptors detect local changes in pH, CO2, or O2, causing local vasomotion.)
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Which of the following would take the longest time to regulate blood pressure?
hormonal control of peripheral resistance
renal regulation
baroreceptor-initiated reflexes
chemoreceptor-initiated reflexes
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Renal Regulation (Renal mechanisms mediate the long-term control of blood pressure by counteracting fluctuations in blood pressure by altering blood volume. For example, if blood pressure is too low, more water will be reabsorbed to the blood from the kidney, thus increasing blood volume and blood pressure.)
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Which of the following would be an effective mechanism to reduce primary hypertension due to an overactive sympathetic vasomotor response?
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Stress Reduction
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A muscle that is being regularly contracted during exercise will attract blood flow by dilating arterioles. Which of these factors would contribute to the effect?
increased levels of carbon dioxide
heat loss from the muscle
increased levels of oxygen
an increase in sympathetic tone
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Increased levels of carbon dioxide. (Carbon dioxide produced in muscle respiration would be a metabolic mechanism, which would dilate local arterioles and increase blood flow.)
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Which of the following intrinsic mechanisms (autoregulation) for controlling arteriolar smooth muscle diameter promotes vasoconstriction?
nitrous oxide
prostaglandins
histamine
endothelins
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Endothelins (Endothelins released from endothelial cells act to balance the vasodilating effects of NO.)
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Which of the following would experience a decreased blood flow during exercise?
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Kidneys (The kidneys and the GI tract (i.e. the stomach and intestines) would have a decreased blood flow during exercise.)
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Which of the following statements does NOT correctly describe tissue perfusion in the cardiovascular system?
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Myogenic control is an example of extrinsic regulation. (Myogenic control, control of the smooth muscle in arteries, is an example of intrinsic regulation.)
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What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries?
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Osmotic Pressure in capillary (Osmotic pressure is based on the concentration of dissolved materials that attract water across a membrane. The osmotic pressure in a capillary (OPc) is the force drawing fluid into the blood at the venous end.)
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Which vessel leaves the right ventricle of the heart to take oxygen-poor, dark red blood into pulmonary circulation?
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Pulmonary Trunk (The pulmonary trunk leaves the right ventricle of the heart to take oxygen-poor, dark red blood into pulmonary circulation. It divides to form the right and left pulmonary arteries.)
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Which vessel(s) return(s) oxygenated blood to the left atrium of the heart to complete the pulmonary circuit?
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Pulmonary Vein (The pulmonary veins collect oxygenated blood from the lungs and return it to the heart.)
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Which of the following vessels would have the lowest blood hydrostatic pressure?
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Pulmonary Vein (The venous return from the lungs would have the lowest pressure of the areas listed.)
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Bulk flow at capillaries is driven by osmotic pressure gradients. (True or False)
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False. (Bulk flow at capillaries is driven by hydrostatic pressure gradients being higher than osmotic pressure gradients at the proximal end of capillary beds.)
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Why is it important that blood pressure drop to lower levels as it reaches the capillary beds?
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because capillaries are fragile and extremely permeable (Low capillary pressures are desirable because capillaries are fragile and high pressures would rupture them. Most capillaries are extremely permeable and thus even the low pressure forces solute-containing fluids out of the bloodstream into the interstitial space.)
