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96 Cards in this Set
- Front
- Back
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The work done by the heart to move blood down a pressure gradient is equal to _____ x _____.
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Pressure x change in volume
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Net work of the heart is equal to the work done by the heart minus ____, or the area inside the _____.
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the work done by the blood on the heart, pressure-volume loop
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The mechanica efficiency of the heart is equal to the _____/ _____.
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Work (P x change in V), chemical energy used
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The mechanical efficiency of the heart is typically less than ___%.
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10
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Most of the energy used by the heart is used to ______, after the blood has been brought to arterial pressure.
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maintain tension
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Once the ventricle has raised the pressure of the blood it contains, ATP continues to be consumed to maintain continued ______, producing _____ heat.
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cross-bridge cycling, tension
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The efficiency of the heart depends largely on the ____ of the myocardial fibers, which is dependent on the end _____ volume.
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length
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Low tension at short myocardial fiber length may be due to low affinity of ____, reduced ____ in T-tubules, and/or reduced calcium sensitivity to_____.
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troponin for Ca2+,
calcium levels, ryanodine receptors. |
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Starling's law states work done by the heart on blood increases with increasing _____ volume.
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end diastolic volume
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_____ is a term that refers to the force acting on the cardiomyocytes prior to the onset of contraction, which is dependent on total force and thickness of the ventricular wall.
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Preload
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The force acting on an individual muscle fiber depends both on the total force and the _____ of the ventricular wall.
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thickness
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The heart contracts _____ forcefully during systole when it is filled to a greater degree during diastole, resulting in an _____ stroke volume and ejection fraction.
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more, increased
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______ refers to the force the ventricle must overcome to eject blood into the arteries, which is the ____ pressure of the aorta.
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after load, systolic
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Increased afterload with a fixed contractility results in a _____ stroke volume and ejection fraction.
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decreased
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Decreased ability of the cardiac muscles to shorten against a _____ afterload will cause a decrease in _____.
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increased, stroke volume
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Increased contractility due the increased ability of the cardiac muscles to _____ causes an _____ in stroke volume resulting from a _____ end systolic volume.
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shorten, increase, decreased
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Increased cardiac output from the right ventrical causes ____ in pulomary vein presure and left ventricle filling.
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increase
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Increased preload causes an _____ in contractility causing a ____ in LV cardiac output.
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increase, increase
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Positive ____ agents cause increased myocardial contraction by increasing ____ in the sarcoplasmic reticulum.
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ionotropic, calcium ions
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Increased Ca2+ occurs by opening ____ channels, inhibiting _____, or inhibiting the ___ pump.
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Ca2+, Na-Ca exchange, Ca2+
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The most important physiologic positive inotropic agents are _____ agonists and ____, which inhibit Na/K pumps in the heart.
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adrenergic(norepinephrine and epinephrine), cardiac glycosides
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Negative inotropic agents decrease mycardial contractility by lowering extracellular ___ or increasing ___ concentration.
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calcium ion, sodium ion
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Rate of Pressure Development = ___/___, and is a measure of ______.
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ΔP/Δt, contractility
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The slope of the length tension diagram is equal to ______.
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contractility
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As preload is increased, the pump performance _____.
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increases
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Sympathetic stimulation greatly ______ pump performance.
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increases
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A cardiac performance curve shifts _____during heart failure, meaning stroke work ____, and left atrial pressure ____.
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down and to the right, decreased, increased
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A cardiac performace curve is shifted _____ by positive inotropic agents and excercise.
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Up and to the left
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Cardiac performance curves are plots of stroke work (____ x____) versus atrial pressure.
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systolic pressure, stroke volume
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Arterial pressure waves become ____ and ____ with increased distance from the heart.
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steeper and narrower
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The heart preferentially adjusts output by changes in ____ rather than stroke volume.
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rate
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Preload is synonymous with the ______ volume.
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EDV
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Increasing the preload with a fixed contractility results in an increased ____ in a healthy heart.
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stroke volume
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A measure of contractility is independent of the ____, ____, and other factors.
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preload, afterload
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Four ways to measure contractility are the _____ fraction, the ______ development obtained by a cardiac catherization, the slope of the ______ diagram, and the ______ curves.
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ejection, rate of pressure development (change in P/change in t), length-tension, cardiac performace curves (systolic pressure x stroke volume versus atrial pressure)
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A suitable approximation of the length- tension diagram is the slope of the ____ versus the maximum pressure diagram.
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end diastolic volume
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The pulse felt in the peripheral arteries is a pressure wave that moves through the blood ____ than the velocity of blood in the arteries.
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faster
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The pulse pressure is ____ in the femoral artery than in the aorta, and the average pressure is ____ than in the aorta.
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greater, slightly less
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Venous pressure waves are caused by the _____ action of the heartbeat during the cardiac cycle, the _____ cycle, and contraction of the _____.
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retrograde, respiratory, skeletal muscles
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The 2 normal heart sounds are S1, the closing of the ____ and ___ valves, and S2 the closing of the ____ valves.
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mitral, tricuspid, semilunar
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Pathological splitting of S1 may result from pathology in the ______ system that accentuates asynchrony in the contraction of the left and right ventricles.
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electrical conductance
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In S1 the ____ valve closes before the ____ valeve, and in S2 the ___ valve closes before the _____ valve.
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mitral, tricuspid, aortic, pulmonary
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Physiological spltting of S_ is accentuated by inspiration, which decreases the pressure in the ____ more than in the aorta.
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2, pulmonary artery
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Pathological splitting of S2 is caused by _____ anomalies, and are _____ accentuated by inspiration.
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conductance, not
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A physiological S3 is heard in _____ and occasionally and is produced early in diastole by _____.
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children, thin adults, the recoil of the ventricular walls following rapid initial ventricular filling
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A pathological S3 sound may be heard when the end ______ is large, as in ______.
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systolic volume, aortic stenosis
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A protodiastolic gallop rhythm is a pathological S_ sound, caused by an _____ in end systolic volume, a decrease in ______, and therefore a stronger recoil in response to ______.
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3, increase, conductance, rapid initial ventricular filling
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A pathogical S4 sound coincides with ____ contraction is found in conditions that produce low ____ compliance.
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atrial, ventricular
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A pathological S4 sound is foun in conditions that produce low compliance, caused by conditions that produce ____ or _____.
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high end diastolic volume, thickening of the ventricular walls
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The opening of the ____ valve may cause an "opening snap" during ____ stenosis.
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mitral, mitral
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Murmurs are produced by ____ flow of blood, when it flows down large pressure gradients and through narrow openings.
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turbulent
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Aortic stenosis produces a ____ murmur.
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systolic
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Mitral stenosis produces a _____ murmer.
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diastolic
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Mitral incompetence produces a ____ murmer.
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systolic
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Murmers can also be caused by narrowing of blood vessels, as in coarctation of the ____ and other pathologies such as ______ or ____ septal defects.
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aorta, patent ductus arteriosus, ventricular
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High pressure baroreceptors reside in the ____ and ____, the arterial side of the circulatory system.
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aortic arch, carotid sinuses
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The aortic depressor nerve is a branch of the ____ nerve, and the carotid sinus nerves are branches of the ____ nerves.
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vagus (X), glossopharyngeal (IX)
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Increased stretch causes an ____ in level of afferent nerve activity from the baroreceptors.
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increased
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The high pressure baroreceptors are strategically located so that the _____ and _____ measure pressures that drive the ____ and ____ blood flow, respectively.
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aortic arch, carotid sinus, coronary, cerebral
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If arterial pressure is chronically elevated, as in systemic arterial _______, the ______ of the walls of the aortic arch and carotid sinus decrease, as well as their sensitivity to ______.
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hypertension, compliance, stretch
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Because of their adaptive response, high-pressure baroreceptors are not effective in ______ pressure control.
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long-term
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Low pressure baroreceptors are also called _____ receptors and are located on the ____ side of system circulation.
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volume, venous
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Low pressure or volume receptors are located in areas such as the ____, _____, and _____.
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atria, vena cava, pulmonary artery
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Stimulated high pressure baroreceptors attempt to lower ______ by decreasing cardiac output by decreasing ____ and ____ or decreasing ______.
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pressure, stroke volume, heart rate, TPR
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High pressure baroreceptors are sensitive to _____ and rate of ______ change.
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MAP, pressure
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The firing rate of individual fibers from the carotid sinus is highest during the _____ of blood pressure.
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upstroke
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Stimulation of low-pressure baroreceptors attempts to lower _____ by increasing renal blood flow via renal ______ and ______ or increasing ______ through the ______ reflex.
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volume, vasodilation, urine formation, HR, Bainbridge
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Blood monitors PO2, PCO2 and pH through vasucalture sensors, called _____ and brain sensors, called _____.
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peripheral chemoreceptors, central chemoreceptors
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______ chemoreceptors located in the aortic arch and carotid bodies, are stimulated by a decrease in P___ and p___ or an increase in P____.
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Periperhal, O2, pH, CO2
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_____ chemoreceptors are stimulated only by an increase in PCO2.
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Central
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_____ chemoreceptors generally have little impact on the cardiovascular system.
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Peripheral
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Peripheral chemoreceptors illicit a cardiovascular system response when _____ function is impaired or when a person is in _____.
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pulmonary, high altitude
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Impairment of pulmonary funciton or high altitude will cause ______ inducing a response from the ______ chemoreceptors.
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hypoxia, peripheral
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With severe hypoxia peripheral chemoreceptors leads to _____ and ______.
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bradycardia, vasodilation
(NOT END RESULT OF HYPOXIA) |
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The increased depth and rate of breathing produced by hypoxia results in the fall of ____ and activation of ______.
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PCO2, central chemoreceptors
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The fall in PCO2 is sensed by ______ chemoreceptors causing _____ and _____.
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central, tachycardia, vasoconstriction
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The end result of hypoxia is _____ and ____.
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tachycardia, vasoconstriction
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In addition to baroreceptors, blood pressure can be influenced by afferent input resulting from somatic and visceral _____, stimulation of _______ receptors and _____ inflation.
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pain, trigeminal cold, lung
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The ______ alters cardiovascualr control secondary to thermoregulation and defense reactions, and the _____ can have direct effects due to emotional stress.
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hypothalamus, cerebral cortex
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Peripheral baroreceptors and chemoreceptors inputs enter the brainstem and synapse within the area known as the _____ in the _____.
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nucleus tractus solitarius, caudal medulla.
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Inhibitory neurons from the NTS project onto the ______ area located in the ventrolateral portion of the medulla.
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vasomotor
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The vasomotor area is divided into 2 areas, the C1 and the A1, which contains neurons that are ____ and unless inhibited by the _____ cause _____.
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tonic, NTS, vasoconstriction
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In the dorsal portion of the medulla is a _______ area which is tonically active, and unless it is attenuated by the ____ both ____ and _____ will increase.
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cardioaccelatory, NTS, heart rate, cardiac contractility
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The vasomotor area causes ______, and the cardioaccelatory causes ______ and _____. Both are _____ active unless inhibited by the ______.
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vasoconstriction, increased HR, increased contractility, tonically, NTS
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Excitatory neurons from the NTS project onto the ______ area.
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cardioinhibitory area
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The cardioinhibitory area consists of the _____ and the
____ of the vagus. |
nucleus ambiguous, dorsal motor nucleus
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Stimulation of the cardioinhibitory area by the NTS causes ____.
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decrease in HR
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The NTS inhibits the _____ and ____ area and stimulates the ______ area.
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vasomotor, cardioacceleratory, cardioinhibitory
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The NTS is continuously stimulated by ____ so it is tonically sending output to reduce the _____ and ____ and stimulate the _____.
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baroreceptors, vasomotor area, cardioacceleratory area, cardioinhibitory area
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If arterial blood pressure increases, ____-pressure baroreceptors increase stimulation to the _____ which inhibits the _____ and ____ and stimulates the ______.
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high, NTS, vasomotor area, cardioacceleratory area, cardioinhibitory area
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Increased arterial blood pressure increases baroreceptor firing to the NTS which inhibts the vasomotor area leading to _____, and inhibits the cardioaccelertory area leading to ______, and stimulates the _______ leading to _______.
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decreased peripheral resistance, decreased heart rate and stroke volume, cardioinhibitory area, decreased heart rate (negative chonotropic agents)
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The ____ area and the _____ area are part of the sympathetic system, while the cardioinhibitory area is part of the parasympathetic system.
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vasomotor, cardioacceleratory
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A decrease in blood pressure _____ afferent output from the baroreceptors, _____ stimultion to the NTS, ____ inhibition to the vasomotor area and _____ stimuation to the cardioinhibitory area.
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decreases, decreasing, decreasing, decreasing
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Decreased stimulation to the NTS, decreases inhibition to the vasomotor area and cardioacceleratory area leading to ____, and decreases stimulation to the ______.
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vasoconstriction, increased stroke volume and heart rate, cardioinhibitory area.
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The mechanisms responsible for local control of blood flow are the _____, arising from the metabolic activity of surrounding cells, and the _____, related to the vessels themselves.
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metabolites or paracrine agents, endothelial and myogenic control
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High cellular metabolic activity causes ______ levels of adenosine, phosphate, PCO2, lacatate, K+, and H+, and a _____ level of O2 causing ____ of the arteriole.
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increased, decreased, vasodilation
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