Term
| Cardiac output from the left side of the heart is known as what? |
|
Definition
|
|
Term
| Cardiac output from the right side of the heart is known as what? |
|
Definition
|
|
Term
| Where is the site of highest resistance in the cardiovascular system? |
|
Definition
|
|
Term
| What arterioles contain alpha-1-adrenergic receptors? |
|
Definition
| Arterioles of the skin, splanchnic, and renal circulations |
|
|
Term
| What arterioles contain beta-1-adrenergic receptors? |
|
Definition
| Arterioles of skeletal muscles |
|
|
Term
| What part of the circulatory system has the largest total cross-sectional and surface area? |
|
Definition
|
|
Term
| What part of the circulatory system contains the highest proportion of the blood in the cardiovascular system? |
|
Definition
|
|
Term
| Are veins under low or high pressure? |
|
Definition
|
|
Term
| What type of receptors are found in veins? |
|
Definition
| Alpha-1-adrenergic receptors |
|
|
Term
| What is the equation for blood flow? |
|
Definition
| v = Q/A where Q = blood flow and A = area |
|
|
Term
| What is the equation for cardiac output/blood flow? |
|
Definition
| Q = (Change in Pressure)/(Total peripheral resistance) |
|
|
Term
| What pressure gradient drives blood flow? |
|
Definition
| Mean arterial pressure - Right artrial pressure |
|
|
Term
| Blood flow is inversely proportional to what? |
|
Definition
| Resistance of the blood vessels |
|
|
Term
| Resistance is directly proportional to what? |
|
Definition
| Viscosity of blood and length of the vessel |
|
|
Term
| Resistance is inversely proportional to what? |
|
Definition
| Fourth power of the vessel's radius |
|
|
Term
| How is parallel resistance calculated? |
|
Definition
| 1/Rtotal = 1/Ra + 1/Rb + ... |
|
|
Term
| How is resistance in a series calculated? |
|
Definition
| Rtotal = Rartery + Rarterioles + Rcapillaries + etc. |
|
|
Term
| When an artery is added in parallel, what happens to the total resistance? |
|
Definition
|
|
Term
| As blood flows through an organ in parallel, what happens to the pressure? |
|
Definition
|
|
Term
| What predicts whether blood flow will be laminar or turbulent? |
|
Definition
|
|
Term
| A larger Reynold's number predicts what? |
|
Definition
| Greater tendency for turbulence |
|
|
Term
| Turbulence in blood flow is responsible for what audible sound? |
|
Definition
|
|
Term
| What increases the Reynold's number? |
|
Definition
| Decreased blood viscosity or increased blood velocity |
|
|
Term
| What describes a blood vessel's ability to stretch? |
|
Definition
|
|
Term
| Capacitance is inversely related to what? |
|
Definition
|
|
Term
| How is capacitance/compliance calculated? |
|
Definition
|
|
Term
| Where is capacitance greater? |
|
Definition
| Veins, allowing more blood volume |
|
|
Term
| Capacitance of arteries naturally decreases with what? |
|
Definition
|
|
Term
| Where is blood pressure highest and lowest? |
|
Definition
| Aorta and venae cavae respectively |
|
|
Term
| Why does the largest decrease in pressure occur in arterioles? |
|
Definition
| Site of highest resistance |
|
|
Term
| What is normal mean aortic pressure? |
|
Definition
|
|
Term
| What is normal arteriole pressure? |
|
Definition
|
|
Term
| What is normal capillary pressure? |
|
Definition
|
|
Term
| What is normal vena cava pressure? |
|
Definition
|
|
Term
| How does arterial pressure fluctuate? |
|
Definition
|
|
Term
| Where is arterial pressure highest during a cardiac cycle? |
|
Definition
|
|
Term
| When is systolic pressure measured? |
|
Definition
| After the heart contracts and blood is ejected into the arterial system |
|
|
Term
| Where is the arterial pressure lowest during a cardiac cycle? |
|
Definition
|
|
Term
| When is diastolic pressure measured? |
|
Definition
| When the heart relaxes in diastole and blood is returning to the heart via veins |
|
|
Term
| The difference between systolic and diastolic pressure is known as what? |
|
Definition
|
|
Term
| What is the most important determinant of pulse pressure? |
|
Definition
|
|
Term
| Why does pulse pressure increase to the same extent as the systolic pressure? |
|
Definition
| Diastolic pressure remains unchanged during ventricular systole |
|
|
Term
| Decreased capacitance would have what effect on the pulse pressure? |
|
Definition
|
|
Term
| The average arterial pressure with respect to time is known as what? |
|
Definition
|
|
Term
| How is mean arterial pressure approximately calculated? |
|
Definition
| Diastolic pressure plus 1/3 the pulse pressure |
|
|
Term
| Why is venous pressure so low? |
|
Definition
| High capacitance = large volumes at low pressure |
|
|
Term
| What is lower, venous pressure or atrial pressure? |
|
Definition
|
|
Term
| What is the order of waves on an on electrocardiogram (ECG)? |
|
Definition
|
|
Term
| What represents atrial depolarization on an ECG? |
|
Definition
|
|
Term
| The PR interval in an ECG is the interval between the beginning of the P wave and the beginning of the Q wave and varies according to what? |
|
Definition
| Conduction velocity through the AV node |
|
|
Term
| What represents the depolarization of the ventricles on an ECG? |
|
Definition
|
|
Term
| The QT interval is the interval from the beginning of the Q wave to the end of the T wave and represents what? |
|
Definition
| Period of depolarization and repolarization of the ventricles |
|
|
Term
| The ST segment on a ECG is what? |
|
Definition
| Segment from the end of the S wave to the beginning of the T wave |
|
|
Term
| What does the ST segment on an ECG represent? |
|
Definition
| Period when the ventricles are depolarized |
|
|
Term
| What represents ventricular repolarization on an ECG? |
|
Definition
|
|
Term
| The resting membrane potential in cardiac APs is determined by the conductance of what? |
|
Definition
|
|
Term
| An inward K+ current has what effect on cardiac membrane potential? |
|
Definition
|
|
Term
| What is the resting membrane potential of ventricles, atria, and the Purkinje system? |
|
Definition
|
|
Term
| What occurs during phase 0 of cardiac APs? |
|
Definition
| Upstroke via transient increase in Na+ conductance, depolarizes the membrane |
|
|
Term
| What occurs during phase 1 of cardiac APs? |
|
Definition
| Brief period of initial repolarization via outward current of K+ and decreased Na+ conductance |
|
|
Term
| When is the plateau of the AP of cardiac APs? |
|
Definition
|
|
Term
| What causes the plateau in phase 2 of cardiac APs? |
|
Definition
| Transient increase in Ca++ conductance, increased K+ conductance |
|
|
Term
| What occurs during phase 3 of cardiac APs? |
|
Definition
| Repolariztion, Ca++ conductance decreases and K+ conductance increases |
|
|
Term
| What occurs during phase 4 of cardiac APs? |
|
Definition
| Inward and outward K+ currents are equal, resting membrane potential approaches K+ equilibrium potential |
|
|
Term
| What is considered the pacemaker of the heart? |
|
Definition
|
|
Term
| What is the intrinsic rate of SA action potential phase 4 depolarization from fastest to slowest? |
|
Definition
|
|
Term
| What occurs during phase 0 of SA action potential? |
|
Definition
| Upstroke via increased Ca++ conductance |
|
|
Term
| What occurs during phase 1 and 2 of SA node action potential? |
|
Definition
|
|
Term
| What occurs during phase 3 of SA node action potential? |
|
Definition
| Repolarization via increased K+ conductance |
|
|
Term
| What occurs during phase 4 of SA node action potential? |
|
Definition
| Slow depolarization via increased NA+ conductance and an inward Na+ current called If. If activated via repolarization during phase 3 |
|
|
Term
| What causes the upstroke of the action potential in the AV node? |
|
Definition
|
|
Term
| The time required for excitation to spread throughout cardiac tissue is known as what? |
|
Definition
| Cardiac conduction velocity |
|
|
Term
| Conduction velocity is dependent on what? |
|
Definition
| Size of the inward current during upstroke |
|
|
Term
| Where is cardiac conduction velocity the fastest and slowest? |
|
Definition
| Purkinje system, AV node respectively |
|
|
Term
| Why is the conduction velocity slowest in the AV node? |
|
Definition
| Allows for ventricular filling before ventricular contraction |
|
|
Term
| What might be the result of increased AV node conduction velocity? |
|
Definition
| Compromised ventricular filling |
|
|
Term
| The ability of cardiac cells to initiate action potentials in response to inward depolarizing current is known as what? |
|
Definition
|
|
Term
| What changes excitability over the course of an action potential? |
|
Definition
|
|
Term
| What reflects the time during which no action potential can be initiated regardless of how much inward current is supplied? |
|
Definition
| Absolute refractory period |
|
|
Term
| When does the absolute refractory period begin and end? |
|
Definition
|
|
Term
| The period during which a conducted action potential cannot be elicited is known as what? |
|
Definition
| Effective refractory period |
|
|
Term
| The period immediately after an absolute refractory period when repolarization is almost complete is known as what? |
|
Definition
| Relative refractory period |
|
|
Term
| What is required for an AP to be elicited during a relative refractory period? |
|
Definition
| More than usual inward current is required |
|
|
Term
| Where do chronotropic effects produce changes? |
|
Definition
|
|
Term
| A negative chronotropic effect elicits what change? |
|
Definition
| Decreases heart rate by decreasing the firing rate of the SA node, increases the PR interval. Positive chronotropic effects have the opposite response |
|
|
Term
| Vagal parasympathetic nerves send signals to all parts of the heart except the ventricles using what neurotransmitter? |
|
Definition
| Acetylcholine via muscarinic receptors |
|
|
Term
| How does parasympathetic innervation via the vagal nerve decrease heart rate? |
|
Definition
| Decreases rate of phase 4 depolarization |
|
|
Term
| What channels do parasympathetic negative chronotropic effects impact? |
|
Definition
| Decreases If channels to decreases inward Na+ current responsible for phase 4 depolarization in the SA node |
|
|
Term
| Sympathetic innervation has what effect on the circulatory system? |
|
Definition
| Increases heart rate, conduction velocity, and contractility via beta-1-adrenergic receptors, constricts vessels via alpha-1- adrenergic receptors |
|
|
Term
| How does parasympathetic vagal innervation decrease the conduction velocity through the AV node? |
|
Definition
| Decreased inward Ca++ current |
|
|
Term
| What neurotransmitter acts on beta-1 receptors? |
|
Definition
|
|
Term
| How does sympathetic innervation increase heart rate? |
|
Definition
| Increased If increases inward Na+ current to increase rate of phase 4 depolarization |
|
|
Term
| How does sympathetic innervation increase conduction velocity through the AV node? |
|
Definition
| Increased inward Ca++ current |
|
|
Term
| What maintains cell to cell cohesion in myocardial cells? |
|
Definition
|
|
Term
| What low resistance paths between cells allow for rapid electrical spread of action potentials? |
|
Definition
|
|
Term
| How do T-tubules differ in myocardial cells vs in skeletal muscle? |
|
Definition
| Forms dyads with sarcoplasmic reticulum, well developed in ventricles but not atria |
|
|
Term
| The magnitude of tension that develops in cardiac muscle is proportional to what? |
|
Definition
|
|
Term
| What re-accumulates Ca++ to the sarcoplasmic reticulum in cardiac muscle? |
|
Definition
|
|
Term
| The intrinsic ability of cardiac muscle to develop force at a given muscle length is known as what? |
|
Definition
| Contractility or inotropism |
|
|
Term
| What can be used to estimate contractility? |
|
Definition
|
|
Term
| What factors increase contractility? |
|
Definition
| Increased heart rate, sympathetic stimulation, cardiac glycosides |
|
|
Term
| What is the positive staircase/Bowditch staircase principle? |
|
Definition
| Increased heart rate increases the force of contraction in a step-wise fashion as intracellular Ca++ increases cumulatively over several beats |
|
|
Term
| What is post-extrasystolic potentiation? |
|
Definition
| The concept that the beat that occurs after an extrasystolic beat has an increased force of contraction because "extra" Ca++ entered the cells during extrasystole |
|
|
Term
| How does sympathetic stimulation increase the activity of Ca++ pumps of the SR? How does this increase contractility? |
|
Definition
| Phosphorylation of phospholamban, more Ca++ is accumulated by SR and available for release in subsequent beats |
|
|
Term
| How does cardiac glycosides increase contractility? |
|
Definition
| Increases force of contraction by inhibiting Na+/K+ -ATPase pump, diminishes Na+/Ca++ gradient and increases intracellular Ca++ |
|
|
Term
| How does parasympathetic stimulation via ACh muscarinic receptors decrease myocardial contractility? |
|
Definition
| Decreases inward Ca++ current during plateau of the cardiac cycle |
|
|
Term
| Pre-load is equivalent to what? |
|
Definition
| End-diastolic volume which is related to right atrial pressure |
|
|
Term
| What happens to end diastolic volume when venous return increases? |
|
Definition
| Right atrial pressure increases due to increasing end-diastolic volume, stretches or lengthens ventricular muscle fibers |
|
|
Term
| Afterload in the left ventricle is equivalent to what? |
|
Definition
|
|
Term
| An increase in aortic pressure has what effect on afterload? |
|
Definition
| Increases afterload on the left ventricle |
|
|
Term
| Afterload for the right ventricle is equivalent to what? |
|
Definition
| Pulmonary artery pressure |
|
|
Term
| Increases in pulmonary artery pressure has what effect on afterload? |
|
Definition
| Increases afterload of the right ventricle |
|
|
Term
| What determines the maximum number of cross-bridges that can form between actin and myosin and in turn determines the maximum tension or force of contraction? |
|
Definition
|
|
Term
| Whe is velocity of contraction maximal? |
|
Definition
|
|
Term
| When is velocity of contraction decreased? |
|
Definition
|
|
Term
| The principles that increases in stroke volume and cardiac output occur in response to an increase in venous return or end-diastolic volume is known as what? |
|
Definition
| Frank-Starling relationship |
|
|
Term
| The Frank-Starling relationship states that increases in end-diastolic volume cause an increase in what? |
|
Definition
| Ventricular fiber length which produces an increase in developed tension |
|
|
Term
| The Frank-Starling relationship matches cardiac output to what? |
|
Definition
| Venous return (greater venous return = greater cardiac output) |
|
|
Term
| Changes in contractility shift the Frank_starling curve in what direction? |
|
Definition
| Increased contractility = upward, decreased contractility = downward |
|
|
Term
| Ventricular pressure curves are constructed by combining what? |
|
Definition
| Systolic and diastolic pressure curves |
|
|
Term
| The relationship between diastolic pressure and diastolic volume in the ventricle is known as what? |
|
Definition
|
|
Term
| The relationship between systolic pressure and systolic volume in the ventricle is known as what? |
|
Definition
|
|
Term
| Increased pre-load has what effect on the ventricular pressure loop graph? |
|
Definition
| Refers to an increase in end-diastolic volume and increases stroke volume basked on the Frank-Starling relationship |
|
|
Term
| Increased afterload has what effect on the ventricular pressure loop graph? |
|
Definition
| Refers to increased aortic pressure which results in decreased stroke volume as the ventricle ejects blood against a higher pressure |
|
|
Term
| What effect does increased contractility have on the ventricular pressure volume loop graph? |
|
Definition
| Increased stroke volume via a decrease in end-systolic volume |
|
|
Term
| Simultaneous plots of cardiac output and venous return as a function of right atrial pressure or end-diastolic volume is known as what? |
|
Definition
| Cardiac and vascular function curves |
|
|
Term
| Which part of the cardiac and vascular function curve depicts the Frank-Starling relationship for the ventricle? |
|
Definition
| Cardiac output/cardiac function curve |
|
|
Term
| The venous return/vascular function curve in a cardiac and vascular function plot depicts the relationship between venous return and what? |
|
Definition
|
|
Term
| What is represented at the point where the vascular function curve on a cardiac and vascular function curve plot intersects the x-axis? |
|
Definition
|
|
Term
| Mean systemic pressure is equivalent to right atrial pressure at what point? |
|
Definition
| When there is no flow in the cardiovascular system |
|
|
Term
| What determines the slope of the venous return curve on a cardiac and vascular function curve plot? |
|
Definition
| Resistance of the arterioles |
|
|
Term
| What is represented at the point of intersection on a cardiac and vascular function curve plot? |
|
Definition
| Equilibrium or steady-state point where cardiac output equals venous return |
|
|
Term
| A clockwise rotation of the venous return curve indicates what? |
|
Definition
| Decrease in total peripheral resistance causing an increase in venous return to the heart |
|
|
Term
| A counterclockwise rotation of the venous return curve indicates what? |
|
Definition
| Increase in total peripheral resistance causing a decrease in venous return to the heart |
|
|
Term
| What effect does an increase in total peripheral resistance have on cardiac output and venous return? |
|
Definition
| Decreases both but right atrial pressure is unchanged. Increased TPR has the opposite effect |
|
|
Term
| The volume ejected from the ventricle in each beat is known as what? |
|
Definition
|
|
Term
| How is stroke volume calculated? |
|
Definition
| End-diastolic volume - end-systolic volume |
|
|
Term
| What equation expresses cardiac output? |
|
Definition
| Cardiac output = stroke volume X heart rate |
|
|
Term
| The fraction of the end-diastolic volume ejected in each stroke volume is known as what? |
|
Definition
| Ejection fraction, related to contractility |
|
|
Term
| What is the normal ejection fraction? |
|
Definition
|
|
Term
| The work the heart performs on each beat is known as what? |
|
Definition
|
|
Term
| How is stroke work calculated? |
|
Definition
| Aortic pressure X Stroke Volume |
|
|
Term
| What is the primary energy source for stroke work? |
|
Definition
|
|
Term
| Cardiac oxygen consumption is directly related to what? |
|
Definition
| Amount of tension developed by the ventricles |
|
|
Term
| How is cardiac oxygen consumption increased? |
|
Definition
| Increased afterload, size of the heart, contractility, and heart rate |
|
|
Term
| What is the Fick principle? |
|
Definition
| Measures cardiac output via (O2 consumption)/(O2pulmonary vein - O2pulmonary artery) |
|
|
Term
| Filling of the ventricle by atrial systole causes which heart sound? |
|
Definition
| Fourth heart sound which is not audible in normal adults |
|
|
Term
| Which wave is atrial systole responsible for on an ECG? |
|
Definition
|
|
Term
| When does isovolumetric ventricular contraction occur on an ECG? |
|
Definition
| Onset of the QRS wave, represents electrical activation of the ventricles |
|
|
Term
| What wave on an ECG represents repolarization of the ventricles and marks the end of ventricular contraction? |
|
Definition
|
|
Term
| What point represents isovolumetric relaxation on an ECG? |
|
Definition
|
|
Term
| What causes the first heart sound? |
|
Definition
| Closure of the AV valves in isovolumetric ventricular contraction |
|
|
Term
| What causes the second heart sound? |
|
Definition
| Closure of the semilunar valves in isovolumetric ventricular relaxation |
|
|
Term
| What causes the third heart sound? |
|
Definition
| Ventricular filling, not normally audible in adults |
|
|
Term
| What kind of feedback system is the baroreceptor reflex? |
|
Definition
|
|
Term
| What is the function of the baroreceptor reflex? |
|
Definition
| Minute-to-minute regulation of arterial blood pressure |
|
|
Term
| Where are baroreceptors located? |
|
Definition
| As stretch receptors within walls of the carotid sinus and aortic arch |
|
|
Term
| What activates baroreceptors? |
|
Definition
| Decrease in atrial pressure in the carotid sinus, increase in atrial pressure in aortic arch |
|
|
Term
| What response by the ANS is elicited by baroreceptors when atria pressure decreases? |
|
Definition
| Decreased parasympathetic outflow to the heart, increased sympathetic outflow tot he heart and blood vessels |
|
|
Term
| What are the effects of the baroreceptor reflex? |
|
Definition
| Increased heart rate, contractility, and stroke volume, vasoconstriction of arterioles, vasoconstriction of veins, all in order to raise blood pressure |
|
|
Term
| What is the slower, hormonal mechanism designed to regulate blood pressure long term? |
|
Definition
| Renin-angiotensin-aldosterone system |
|
|
Term
| How does the renin-angiotensin aldosterone system regulate blood pressure? |
|
Definition
|
|
Term
| What does the enzyme renin activate after being secreted in response to a decrease in renal perfusion pressure? |
|
Definition
| Catalyzes the conversion of angiotensinogen to angiotensin I in plasma |
|
|
Term
| What converts angiotensin I to angiotensin II and where does this occur? |
|
Definition
| Angiotensin-converting enzyme (ACE) in the lungs |
|
|
Term
| What are the effects of ACE inhibitors? |
|
Definition
| Inhibits ACE to block the conversion of angiotensin I to II, decreases blood pressure |
|
|
Term
| What are the effects of angiotensin II? |
|
Definition
| Stimulates aldosterone secretion to increase Na+ reabsorption which water then follows, causes vasoconstriction of arterioles to increase total peripheral resistance and mean arterial pressure |
|
|
Term
| Chemoreceptors in the carotid and aortic bodies respond to what signals? What response is elicited? |
|
Definition
| Decreases in oxygen, produces vasoconstriction, increase in total peripheral resistance, and increases arterial pressure |
|
|
Term
| Vasopressin is involved in the regulation of blood pressure in response to what? |
|
Definition
| Hemorrhage via vasoconstriction and water reabsorption |
|
|
Term
| What does the atria release in response to an increase in atrial pressure? What are its effects? |
|
Definition
| Atrial natriuretic peptide, relaxes vascular smooth muscle, decreases total peripheral resistance, increases Na+ and water excretion |
|
|
Term
| The smooth muscle band at the junction of arterioles and capillaries is called what? |
|
Definition
|
|
Term
| True capillaries lack smooth muscles and are defined as what? |
|
Definition
| Single layer of endothelial cells surrounded by a basement membrane |
|
|
Term
| What allows passage of water soluble substances in true capillaries? |
|
Definition
| Clefts/pores between endothelial cells |
|
|
Term
| What controls blood flow through capillaries? |
|
Definition
| Contraction and relaxation of the arterioles and precapillary sphincters |
|
|
Term
| How do lipid-soluble substances cross membranes of capillary endothelial cells? |
|
Definition
| Simple diffusion (ex. oxygen, carbon dioxide, etc.) |
|
|
Term
| Where are clefts/pores in endothelial capillary cells exceptionally tight or wide? |
|
Definition
| Tight in blood-brain barrier, wide in liver and intestines for passage of proteins (aka sinusoids) |
|
|
Term
| According to the starling equation, a positive J (fluid flow) means what in capillaries? |
|
Definition
| Net movement is out of the capillary |
|
|
Term
| What does K(f) represent in the Starling equation? |
|
Definition
|
|
Term
| What does P(c) represent in the Starling equation? |
|
Definition
| Capillary hydrostatic pressure |
|
|
Term
| An increase in capillary hydrostatic pressure has what effect on the capillary? |
|
Definition
| Favors filtration out of the capillary |
|
|
Term
| What does P(i) represent in the Starling equation and what is its relationship with capillary filtration? |
|
Definition
| Interstitial fluid hydrostatic pressure, opposes filtration outof the capillary |
|
|
Term
| How is excess filtered fluid and filtered protein returned to the capillaries? |
|
Definition
|
|
Term
| What permits interstitial fluid to enter, but not leave, lymph vessels? |
|
Definition
|
|
Term
| What occurs when the volume of interstitial fluid exceeds the capacity of the lymphatics to return it to circulation? |
|
Definition
|
|
Term
| What are the effects of endothelium-derived relaxing factors (EDRF)? |
|
Definition
| Relaxation of vascular smooth muscle via production of cyclic guanosine monophasphate (cGMP) |
|
|
Term
| What is a well known endothelium-derived relaxing factor? |
|
Definition
|
|
Term
| What organs exhibit autoregulation of blood flow? |
|
Definition
|
|
Term
| What is the definition of active hyperemia? |
|
Definition
| Blood flow to an organ is proportional to its metabolic activity |
|
|
Term
| What is reactive hyperemia? |
|
Definition
| An increase in blood flow to an organ that occurs after a period of occlusion of flow |
|
|
Term
| What basic principle guides the range of reactive hyperemia? |
|
Definition
| Longer periods of occlusion result in greater increases in blood flow above preocclusion levels |
|
|
Term
| What is the myogenic hypothesis of local control of blood flow based on? |
|
Definition
| Vascular smooth muscle contracts when it is stretched, explains autoregulation |
|
|
Term
| What is the metabolic hypothesis of local blood control of blood flow based on? |
|
Definition
| Tissue supply of oxygen is matched by tissue demand of oxygen via vasodilator metabolites, explains active hyperemia |
|
|
Term
| What vasoactive hormones cause arteriolar dilation and venous constriction? |
|
Definition
| Histamine, Bradykinin, Serotonin (arteriolar constriction only) |
|
|
Term
| Which vasoactive hormone causes local edema? |
|
Definition
|
|
Term
| Which prostaglandins are vasodilators? |
|
Definition
| Prostacyclin and E-series prostaglandins |
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Term
| What prostaglandins are vasoconstrictors? |
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Definition
| F-series prostaglandins, thromboxane A(2) |
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Term
| What controls coronary and cerebral circulation? |
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Definition
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Term
| What are the most important metabolic factors in coronary circulation? |
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Definition
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Term
| What is the most important local vasodilator in cerebral circulation? |
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Definition
| Carbon dioxide, an increase causes vasodilation to increase blood flow to the brain |
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Term
| Why do vasoactive substances in the systemic circulation have little effect on cerebral circulation? |
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Definition
| Blocked by blood brain barrier |
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Term
| What sympathetic receptors are found in skeletal muscle blood vessels and what are their effects? |
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Definition
| Alpha-1 = vasoconstriction, Beta-2 = vasodilation |
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Term
| What are the local vasodilator substances in skeletal muscle? |
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Definition
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