click below
click below
Normal Size Small Size show me how
Exercise Physiology
Exam 2
Question | Answer |
---|---|
the volume of blood pumped by the heart per minute is referred to as | cardiac output |
according to lecture, the principle by which the heart works to pump blood is due to | pressure differences |
in an elite athlete, which of the following is true concerning stroke volume | increased stroke volume at rest increased stroke volume at a standardized submaximal rate of work increased stroke volume at maximal rates of work |
what organ system receives the majority of blood flow during exercise | skeletal muscle |
what organ system receives less blood flow (% and absolute) during exercise | intestines/kidneys/liver/spalnchic bed |
increases in cardiac output during exercise at an intensity above 80% of maximum are largely the result of increased... | heart rate |
stroke volume increases with increasing rates of work up to an exercise intensity of ___% of maximal capacity | 40 to 60 |
EDV - ESV | SV |
if myocardial contractility is decreased, which of the following will increase? | ESV |
in order to redistribute blood flow at the onset of exercise, the sympathetic nervous system stimulates ______________, while local factors (CO2, temp, H+) stimulate _____________ to increase blood flow to working skeletal muscle | vasoconstriction, vasodilation |
Determinants of stroke volume (SV) include | ventricular distensibility and contractility the volume of venous blood returned to the heart the aortic or pulmonary arterial pressure |
True or False resting cardiac output averages about 5L/min in healthy adults | true |
True or False a positive chronotropic effect upon the heart will increase HR | true |
True or False Maximal cardiac output can exceed 30L/min in elite endurance athletes | true |
cardiorespiratory endurance training will cause which of the following changes? | an increase in plasma volume and an increase in red blood cell volume |
at very high heart rates during cardiorespiratory endurance exercise, stroke volume may decrease because of... | inadequate ventricular filling resulting from a shortening of diastole |
cardiorespiratory endurance training causes | an increase in left ventricular chamber size an increase in myocardial wall thickness |
the largest part of the increase in maximal oxygen uptake in response to endurance training results from | increased cardiac output and muscle blood flow |
over years of training, maximal oxygen uptake tends to stabilize. Further improvements in an endurance athlete's performance (race pace) are most likely due to | increased lactate threshold |
the Fick equation indicates that the rate of oxygen consumption is equal to | cardiac output times a-VO2 difference |
cardiorespiratory endurance-trained athletes are able to achieve much higher maximal cardiac outputs than the average person because of | an increased maximal stroke volume and an increased ventricular size |
the heart of a highly trained endurance athlete would be characterized by | increased end-diastolic pressure increased left ventricular wall thickness increased ejection fraction |
in response to cardiorespiratory endurance training, what occurs to cardiac output | maximal cardiac output is substantially increased |
following training, RBC volume will (increase/decrease) | increase |
following training, hematocrit will (increase/decrease) | decrease |
following training, hematocrit with decrease due to an (increase/decrease) in _________________ | increase in plasma volume |
the normal pacemaker of the heart is the | sinoatrial node |
what is responsible for increasing HR to values above 100bpm | sympathetic nervous system |
parasympathetic stimulation of the heart... | is mediated by the vagus nerve |
stroke volume equals | EDV - systolic volume |
blood to the skeletal muscles in pumped from which chamber of the heart | left ventricle |
skeletal muscles receive approximately ______% of the total cardiac output under resting conditions, but they can receive as much as ____% of cardiac output during heavy endurance exercise | 15;80 |
true or false parasympathetic stimulation of the heart causes the heart rate to increase | false |
true or false the heart does not have to receive an impulse from the sympathetic nervous system to in order to contract | true |
true or false a positive inotropic effect upon the heart will increase contractility | true |
how does stroke volume change with aerobic training | increased SV at rest increased SV at a standardized submaximal rate increased SV at maximal rates of work |
the ratio of total blood cell mass to total blood volume is referred to as | hematocrit |
the oxygen-carrying function of the blood is provided by | hemoglobin |
aerobic training results in what heart rate adaptations? | decrease in resting HR lower HR at a standard submaximal rate of work |
the average hematocrit for a human is approximately ____% | 40 to 45 |
an increase in RBC without an equivalent increase in plasma volume results in | increased blood viscosity |
at very high HR during cardiorespiratory endurance exercise, stroke volume may decrease because of... | inadequate ventricular filling resulting from a shortening of diastole |
what allows an increase in muscle blood flow during submaximal and maximal exercise after cardiorespiratory endurance training | increased capillarization of trained skeletal muscle greater utilization of existing capillaries in trained skeletal muscles more effective distribution of blood |
what would not contribute to increased endurance performance | a decrease in lactate threshold |
what is the best objective laboratory measure of aerobic power, or cardiorespiratory endurance? | maximal oxygen uptake |
echocardiography can used to view and measure or monitor... | thickness of heart walls action of the heart valves size of the heart chambers |
according to lecture, the measurement of VO2 is synonymous with | cardiovascular function |
the best objective measure for cardiovascular function | VO2max |
the best objective measure for cardiac function is | cardiac output (Q) |
the concept of preload as it relates to improved cardiac hemodynamics is best described by what relationship | Frank-Starling |
an increase in the vigor of contraction is termed a positive _________effect | inotropic |
a positive inotropic effect is normally a function of the _________________ nervous system | sympathetic |
decreased vigor of contraction is termed a positive _____________ effect | inotropic |
a negative inotropic effect is normally a function of the ______________ nervous system | parasympathetic |
changes in vigor of contraction are a result of the amount of ___________ released into the mycardium | calcium |
the heart works as a pump by creating a positive ____________ differental | pressure |
the hydraulic pump system of the heart is affected by length _____________ of the vessel, and the ______________ of the blood, described by ______________ law | radius/diameter; viscosity; posielles |
ventilation = | TV*Bf(rr) |
during exercise, the ventilation perfusion ration Ve/Q | increases |
increased Ve during exercise is primarily stimulated by increased blood levels of ________ | CO2 |
increased Ve at the onset exercise is primarily due to __________ factors | neural |
True or False the Bohr effect increases loading of oxygen in the lungs | false |
the mechanism for movement of air into and out of the lungs is _______________ | ventilation |
ventilation is accomplished by muscle contractions that increase lung volume (inspiration) and decreases lung volume (expiration). These changes conform to ___________ law | Boyles |
True or False lung volumes increase significantly with training | false |
resting lung volumes are measured with a technique called _____________ | spirometry |
alveolar ventilation = | T(v-deadspace) * Bf (rr) |
the oxygen cascade was described as it relates to this gas law | Dalton's law |
True or False the ventilatory equivalent of O2 decreases during incrementally increasing exercise | false |
following training, blood lactate levels are __________ at the same absolute exercise intensity | lower |
following training, the lactate threshold will | shift right |