cardiovascular system

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cardiovascular system
2013-10-29 01:00:21

exam 2
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  1. systemic circulation
    recieves blood from the left ventricle
  2. tricuspid valve
    the valve that prevents regurgitation of blood from the rightventricle to the atrium
  3. semilunar valves
    prevent backflow of blood from the arteial trunks to the ventricles
  4. the wall of the left ventricle is thicker than the wall of the right ventricle b/c
    the left ventricle must pump the same amount of blood into a higher-resistance, higher- pressure system
  5. adjacent cardia muscle cells are joined together end-to-end in the ventricles by
    intercalated discs
  6. the primary function of the pericardial sac is to
    secrete fluid that reduces friction as the heart beats
  7. chordae tendineae
    keeo the AV valves fom everting during ventricular systole
  8. the heart chamber that has the greatest amount of work load is
    the left ventricle
  9. a lumen that contains blood with a comparatively higher concentration of oxygen is in the
    pulmonary veins
  10. the aortic valve
    prevents backflow of blood into the left ventricle during ventricular diastole
  11. the right half of the heart pumps blood through the
    pulmonary circut
  12. the left half of the heart pumps blood through the
    systemic circuit
  13. blood returning from the lungs
    enters the left atrium
  14. blood flow pattern during one pass through the heart and lungs
    right ventricle > bicuspid valve > aortic valve
  15. gap junction
    the low-resistence pathway that permits electrical activity to pass from cell-to-cell in myocardial tissue
  16. what component of the cardiac conduction system distributes electrical signals through the papillary muscle directly?
    purkinje fibers
  17. this causes the plateau of the cardiac action potential
  18. opening of the voltage-gated slow calcium channelin the plasma membrane of the contractile cell
  19. action potentials of the heart
    • the rising phase of the AP in autorhythmic cells is due to a rapid CA2+ influx
    • the rising phase of the AP in contractile cells is due to a rapid Na+ influx
    • the plateau phase of the AP in the contractile cll is due to a slow Ca2+ influx
  20. On a normal ECG, a wave for repolarization of the atria is not recorder b/c
    it occurs simultaneously with ventricular depolarization and is masked by the QRS complex
  21. for the heart to function efficiently
    excitation and contraction of the cardiace fibers of each hear chamber should be coordinated to ensure efficient pumping, and the atria should be excited and contract before the onset of ventricular contraction to ensure that ventricular filling is complete
  22. the AV nodal delay ensures that
    the atria contract and empty their contents intot he ventricles prior to venticular systole
  23. SA Node
    the normal pacemaker of the heart
  24. the function of the atrioventricular node is ot
    prevent the atria and ventricles from contracting simultaneously
  25. the direction of the impulse throught the conduction system of the heart is normally....
    SA node > AV node> bundle of His > purkinje fibers
  26. the QRS complex represents
    depolarization of the ventricles
  27. the fastest rate of autorhythmicity is normally carried out by the
    SA node
  28. depolarization occurs at the  AV node
    between the P wave and the QRS complex
  29. Which of the ECG waves represents ventricular repolarization?
    the T wave
  30. the normal sequence of the spread of cardiac excitation
    SA node> atria> AV node> bundle of His> purkinje fibers> ventricular myocardium
  31. extrasystole of the heart means
    that the heart produces a premature beat
  32. The SA is the heart's normal pacemake bc
    it has the fastest rate of autorhythmicity
  33. fibrillation
    uncoordinated excitation and contraction of cardiac cells
  34. AV node
    is the only electrical connection btwn the atria and the ventricles
  35. the electrocardiogram is the most useful in determining which componenet of the cardiac output?
    heart rate
  36. an ectopic focus is the place where
    an abnormly excitable area of the heart initiates a premature AP
  37. the function of the ventricular conduction system of the heart is to
    to spread the AP throughout the ventricle to ensure a single, coordinated contraction of both ventricles
  38. the refractory period of cardiac muscle
    • lasts almost as long the contraction period
    • is much longer than the refratory period in the skeletal muscle
    • prevents tetanic contraction of the heart to occur to ensure smooth, coordinated ejection of blood from the ventricles
  39. the membrane potential of cardiac muscle cells at rest
    is about -90mV
  40. why can't tetanus occur in the heart?
    the refractory period in cardiac muscle lasts almost as long the contraction
  41. during the isovolumetric phases of the cardiac cycle
    all the heart valves are closed
  42. the volume of blood ejected from each ventricle during a contraction is called the
    stroke volume
  43. the cardiac output is equal to
  44. decreased preload
    decreases cardiac output
  45. if the connection btwn the SA node and the AV node becomes blocked
    the ventricles will beat more slowly
  46. when your sympathertic nervous system is more active
    • the SA node depolarizes more rapidly
    • the myocardium repolarizes more rapidly
    • more Ca2+ becomes avialble and causes more forceful heart conctrations
    • NE is stimulating the heart
  47. which of the following decreases ESV?
  48. What precentage of ventricular filling is normally accomplished before atrial contraction begins
  49. vagal influences on the heart results in
    enhanced potassium permeability at the SA node and less frequent depolarization of the SA node
  50. a condition in which the heart is contracting in an uncontrolled, rapid, and irregular manner
    is fibrillation and can be treated with administration of an electrical current
  51. the heart
    is sympathetically innervated via cardiac nerve fibers and is parasympathetically innervated by vagus nerve fibers
  52. when the heart is sumpathetically stimulated
    it is responding to NE and Ca2+ channels are opening in greater numbers
  53. the second heart sound is produced by the
    closing of the semilunar valves
  54. the first heart sound
    occurs when the AV valves close, and signals the onset of ventricular systole
  55. the aortic valve opens
    when the ventricular pressure exceeds aortic pressure
  56. during isovolumetric contraction
    no blood enters or leaves the ventricles
  57. the perirod lasting from closure of the AV valves to opening of the aortic valve is know as
    isovolumetric ventricular contraction
  58. the heart vavle open and closes due to
    pressure differences on the valve's 2 sides
  59. cardiac output
    is the volume of blood pumped by each ventricle per minute, and equals heart rate x stroke volume
  60. the dicrotic notch on the aortic pressure curve is due to
    disturbance set up by the aortic valve closing
  61. **** an insufficient AV valve
    allows blood to backflow into the ventrcile during diastole ?
  62. atrial flutter
    characterized by a 2:1 rhythm as impulses pass form the AV node to the ventcles
  63. a whistling murmur heard between the second and first hear sound would be indicative of
    a stenotic AV valve
  64. at rapid heart rates
    systole stays almost constant but diastole shortens
  65. 12 complete ECG patterns are recorded over 10 seconds, which means the heart rate is...
    72 beats per minute
  66. if stroke volume is 80 mL and the heart rate is 70 beats per minute, the stroke volume average would be....
    • CO= HR x SV
    • CO= 80x 70
    • CO = 5,600 mL/min
  67. if cardia output is 4,800 mL/min and the heart rate is 60 beats per minute, then the stroke volume average is...
    • CO= HR x SV
    • 4800/60 = SV
    • = 80mL
  68. according to the Frank-Starling law of the heart
    increasing venous return increase EDV, which leads to an increased stroke volume
  69. During heart failure
    the heart pumps out a smaller stroke volume that normal for a given EDV, and a compensatory increase in sympathetic activity increases the contracility of the heart to normal in the early stages of the disease
  70. systole means
  71. parasympathetic innervation of the heart
    • involves the vagus nerve
    • decrease the rate at which the pacemake potential reaches threshold
    • decreases the strength of ventricular contraction
  72. sympathetic stimulation of the heart
    • increases the heart rate
    • increases the heart's contractility 
    • shifts the Frank-Starling curve to the left
    • involes the release of NE
  73. rheumatic fever
    the heart conduction system is disrupted
  74. increased ______ permeability of the nodal cells hyperpolarizes the SA node
  75. the parasympathetic nervous system has little effect on _____ activity
  76. if the EDV were held constant, increased cardia output, could be accomplised by
    decreas parasympathetic stimulation of the heart
  77. increase in stroke volume
    • increased EDV
    • increased contractility
    • increased preload
    • increased venous return
    • NOT increase ESV
  78. the cardiac muscle
    reveives most of its blood supply during ventricular diastole by means of the coronary circulation
  79. a metabolic predictor of heart disease ta is independent of one's cholesterol/lipid profile is
  80. at rest, which of he following recieves the most blood flow?
  81. vasodilation of coronary arteries is induced by
    • nitric oxide
    • adenosine
    • nitroglycerin
  82. resistance
    is the measure of the hinderance to blood flow through a vessel caused by friction btwn the moving fluid and stationary vascular walls, and increases 16-fold when the radius of the vessel is reduced by one-half
  83. resistance increases when
    radius decreases
  84. vasconstriction
    refers to the decrease in the radius of the vessel, and vasconstriction of an arteriole decreases blood flow through that vessel
  85. the relationship btwn pressure, flow, and resistance
    flow = pressure gradient/ resistance
  86. blood flow is affected by
    • pressure differences
    • the viscosity of the blood
    • the amount of friction in the blood vessels
    • the length and diameter of the blood vessels
  87. the major determinant influencing resistance to blood flow is the
    radius of the vessel through which the blood is flowing
  88. in an arteriole, i the blood vessel radius is 2 units and is then vasoconstricted to 1 unit
    resistance increase 16x
  89. the larger arteries assit with systemic blood flow to tissues by
    eleactic recoil of their walls
  90. blood pressure
    • it is maximal during ventricular systole
    • decreases the farther away from the heart
    • it increases with increasing resistance
    • it decrease with increase vessel diameter
    • IT CANNOT! be increased by direct parasympathetic activit
  91. will produce a great change in blood flow
    double the radius of the vessel
  92. type of blood vessel that consists of only one cell layer
  93. microcirculation is composed of
    arterioles, capillaries and venules
  94. organs that recondition blood
    recieve disproportionately large percentages of the cardiac output and can withstand temporary reductions in blood flow much better than organs that do not recondtion blood
  95. arteries
    serve as rapid-transit passageways from the heart to the organces bc of their large radii
  96. the major function of the arterioles is to
    regulate flow of bld through capillary beds and distribute the cardiac output to tissues
  97. because arteries are elastic
    arteries act as a pressure reservoir for maintaining blood flow during diastole
  98. the pressure measured in the arteries just before the next ventricular ejection of blood is
    diastolic pressure
  99. veins
    serve as a blood reservoir
  100. the pulse pressure is
    the difference btwn the systolic and diastolic pressures
  101. mean arterial pressure
    diastolic pressure + (pulse pressure/3)
  102. if the arterial blood pressure is recorded at 132/84, what is the mean arterial pressure
    100 mmHg
  103. if the pulse pressure is 44 mmHg and the diastolic pressure is 68 mmHg , the systolic pressure is
    112 mmHg
  104. what force continues to drive blood through the vasculature during ventricular diastole?
    elastic recoil of the streched arteries
  105. the most important factor that increase blood flow through a specific tissue to meet the tissues needs
    cellular products that cause local vasodilation
  106. properties of arterioles
    • the walls contain a thick layer of SM
    • they are responsible for the distribution of blood flow to the various organs
    • they are major vessels that contribute to total peripheral resistance
    • they are richly innervated by sympathetic nerve fibers
    • their radii DO NOT remain constant
  107. active hyperemia
    as metoblic activity of an organ or tissue increases, blood flow to that organ increases
  108. local chemical changes that occur during a period of increased cell activity
    • increased CO2 
    • increased K+
    • increased acid
    • increased osmolarity
    • NOT descrease adenosine release
  109. local chemical factors associated with vasodilation of arterioles
    • increased CO2
    • increased acid
    • decreased O2
    • histamine release
    • NOT descrease prostaglandins in the tissue fluid

  110. increased respiration within the tissue leads to vasodilation of the aterioles bc
    carbon dioxide levels increase and oxygen levels decrease
  111. nitric oxide
    • it relaxes digestive tract SM
    • the direct mediator of penile erection
    • it is released as "chemical warfare" by macrophages of the immune system
    • it serves as a novel type of NT in the brain
    • it DOES NOT increases the total peripheral resistance by its action on arteriolar SM
  112. extrinsic control of arteriolar radius
    • is accomplished primarily by the sympathetic nervous system
    • is important in the regulation of arterial blood pressure
    • can be overrideen by local adjustmants
  113. during strenous exercise, blood flow increases to
    the heart bc of the local control factors and skeletal muscles bc of local control factors
  114. most sympathetic fibers release ______ at arterioles
  115. the major site of sympathetic blood flow control (resistance changes) is at the
  116. increase in local factors produces the relaxation of arteriolar SM
    • acid
    • carbon dioxide
    • osmolarity 
    • potassium
    • NOT oxygen
  117. the myogenic response refers to vascular SM's tendency to
    constrict when stretched
  118. causes arteriolar vasodilation
    • decrease sympathetic stimulation
    • local decrease in O2
    • histamine
    • application of heat
    • NOT myogenic response
  119. during exercise there is not an increase of blood flow to the...
  120. what factor will reduce total peripheral resistance?
    anaphylactic shock
  121. binding of epinephrine to alpha receptors causes SM to
    relax in the skeletal muscle arteries
  122. active hyperemia
    refers to the arteriolar dilation in respone to local chemical changes that accopany increased metabolic activity of the tissue
  123. characteristics of capillaries
    • thin walls
    • short distance between adjacent vessels
    • slow blood velocity
    • large total SA
    • NOT distensible walls
  124. the largest total cross-sectional area is found in the
  125. through what vessel is the velocity of blood flow the slowest?
  126. the velocity of blood flow in capillaries is
    slow enough to favor adequate exchange of nutrients and wastes
  127. as the total cross-sectional area of the vascular tree ______, the velocity of blood flow ________
    • increases: cross- sectional area
    • decrease: blood flow
  128. in most tissues, glucose (water soluble) crosses the capillary walls through
    water-filled pores
  129. the movement of fluid across the capillary all is influenced by
    • capillary blood pressure
    • interstitial fluid hydrostatic pressure
    • plasma osmotic pressre
    • interstitial fluid osmotic pressure
  130. the procee of ultrafiltration
    movement of protein-free plasma from the capillaries into the interstitial fluid and occurs when capillary blood pressure plus interstitial fluid osmotic pressure exceed blood-osmotic pressure plus interstitial fluid hydrostatic pressure
  131. fluid movement into and out of the capillary is dependent on _____ and pressures working in the ______ direction
    • hdyrostatic
    • osmotic
    • different
  132. the principle force that causes movement of fluid from the tissues into the capillaries is the....
    osmotic pressure created by the plasma proteins
  133. what is the primary method by which materials such as OCO2 and nutrients are exchanged between the blood and surrounding tissues?
    passive diffustion of substances across the capillary wall down their concentration gradients
  134. this change will increase fluid reabsorption by the capillaries
    increased blood osmotic pressure
  135. this alteration could lead to edema
    a fall in concentration of plasma proteins and blocked lymph vessels
  136. What is the primary reason that edmema may occur with serious burns?
    lowering of blood osmotic pressure due to the loss of protein-rich fluid from the surface of the burn
  137. edema could result from
    • blockage of lymph vessels
    • increased capillary blood pressure
    • decreased blood osmostic pressure
  138. factors that promote the function of the capillaries
    • a blood pressure focring fluid out of these vessels
    • an osmotic pressure drawing fluid into these vessels
    • pores in the endothelial wall
    • thin walls
    • NOT a small total surface area
  139. conditions that are associated with edema
    • extensive burns
    • congestive heart failure
    • blocked lymphatics
    • increase venous pressure
  140. functions of the lymtphatic system
    • defense against disease
    • return of fluid to the ciculatory system
    • transport of fat molecules
    • return of proteins to the circulatory system
    • NOT regulation of sodium balance
  141. the veins
    can serve as blood reservoir by adjusting their total capacity to accommodate variations in blood volume
  142. which vessels contain the highest percentage of total blood volume?
    systemic veins
  143. the venous valves
    passively close to prevent the backflow of blood in the veins
  144. heart and venous valves serve a similar function. the prevent a ______ flow of blood
  145. sympathetic stimulation of veins _____ venous pressure and drives ______ blood into the heart
    • increases pressure
    • drives more blood into the heart
  146. what of the following factors aids venous return to the heart?
    the skeletal muscle pump squeezing blood through veins and respiratory pump providing a pressure gradient between the lower and chest veins
  147. the 2 determinants of mean arterial pressure are
    • cardiac output
    • total peripheral resistance
  148. factors that promotes an increase in blood pressure
    • epinephrine
    • aldosterone
    • angiotensin II
    • water retention
  149. when blood pressure becomes elevated above normal
    parasympathetic stimulation of the heart increases
  150. short-term adjustments in blood pressure are mediated by
    baroreceptor reflexes and changes in cardiac output
  151. this compensates for a fall in blood pressure below normal
    • increased cardiac output
    • increased heart rate
    • venous vasoconstriction
    • increased stroke volume
    • NOT a decrease in total peripheral resistance
  152. sympathetic stimulation effects on blood pressure
    • constricts arterioles, which increases peripheral resistance
    • increases stroke voulme, which increases cardiac output
    • constricts veins, which increases stroke volume and venous return
    • IT DOES NOT decreases end diastolic volume, which increases cardiac output
  153. receptors that detect changes in the blood pressure are located in the
    carotid sinus and spinal cord
  154. regulation of arterial pressure is mediate by reflex mechanism. one important pressure receptor _________ located in the _________
    baroreceptor and it is located in the coratid sinus
  155. the cardiovascular center responds to rising H+/ CO2 by
    constricting arterioles
  156. when the receptor potential of the baroreceptors decreases, the cardiovascular center responds by bringing about an increase in
    • stroke volume
    • venous return
    • total peripheral resistance
  157. hypertension
    refers to a chronic state of increased arterial pressure
  158. a sudden increase in pressure within the carotid sinus leads to
    increased parasympathetic nerve activity
  159. compensation for hemorrhage
    • shift of fluid from the interstitial fluid into the plasma
    • reduced urinary output
    • increased cardiac output
    • increased synthesis of plasma proteins
    • NOT increased capillary permeability
  160. hypertensioned may be caused by
    • renal disease
    • hardening of the arteries
    • salt imbalances
    • adrenal medullary tumors
    • NOT overactive baroreceptors
  161. shock may develop from
    • loss of blood 
    • low cardiac output
    • decreased venous return
    • excessive vasodilation
  162. compensation mechanisms for blood loss
    • fluid shift from ICF to plasma
    • venous vasconstriction
    • thirst
    • increased renal reabsorption of salt and water
    • NOT lowered angiotensin II production
  163. varicose vein develop mainly from the incopetent function of the
  164. the carotid sinuses and aorta contain receptors that are sensitive to changes in
    blood pressure
  165. mitral
    • bicuspid valve
    • left artia and left ventricle
  166. tricuspid
    between the right ventricle and the left ventrical
  167. aortic valve
    • left venticle to aorta
    •  aortic semilunar
  168. pulmonary valve
    • pulmonary semilunar 
    • right ventricle and the pulminary artery/truck
  169. syncytium
    AP spreads rapidly
  170. diastole
    • relaxation 
    • dilation
    • filling
    • ventricular muscle re-establishing
    • vetricles slowly increasing volume
    • isovolumic relaxation 
    • AV valve is open ,rapid inflow of blood ,atrial systole (following the p-wave)
  171. systole
    • contractoin
    • AP stimulated contraction
    • ventricle quickly reduces volume
    • isovolumic contraction
    • AV valves close, aortic valves open, ejection phase, aortic valve closes
  172. 3 layers of the heart
    • epicardium (visceral layer): thin transparent outer layer of the heart wall
    • myocardium: thick middle layer composed of cardiace muscle
    • endocardium: SM
  173. during artial systole
    ventricles are relaxed
  174. ventricle systole
    atria are relaxed
  175. after load
    • the tension developed in the walls of the left ventricle from the aorta (or pulmonary artery) that the muscle must contract against
    • pressure ventricle must overcome to contract
  176. atrial pressure
    • minor a, c, v waves
    • a= atrial contraction; slight increase in atrial pressure
    • c= starts with ventriclular contraction from AV valvs bc of increasing ventricular presure and backflow of blood in the atria
    • v= flow of blood in the atria, occurs towards the end of ventricular contraction. once contration is over, AV valves open again
  177. ventricular pressure
    • icreases dramatically after AV valve closes and falls abruptly before the AV valves open 
    • accounts for most of the heart's pumping ability
  178. pre-load
    • end-diastolic pressure
    • the tension on the muscle before it contracts
    • pressure during the filling of the ventricle
  179. phonocardiogram
    comes from sounds made by open/closing the heart valves
  180. T wave
    rapid repolarization of the ventricles
  181. the more the heart is stretched
    the greater the force of contraction
  182. excess K+ and Ca2+
    • excessK + causes the heart to become dilated and slows HR
    • excess Ca2= causes heart to become spastic
  183. hyperthemia vs hypothermia
    • hyperthermia/fever: HR increases
    • hypothermia:  HR decreases