The increase in cardiac output that occurs during exercise is due to_________

The increase in cardiac output that occurs during exercise is due to_________a.both an increase in mean arterial pressure and a decrease in vascular resistance.b.an increase in mean arterial blood pressure only.c.a decrease in vascular resistance only.d.an increase in heart rate and a decrease in mean arterial blood pressure.

During heavy-intensity exercise, increases in cardiac output are associated with increases in_________a.the % of cardiac output increases, and the volume of blood increasesb.the % of cardiac output decreases, and the volume of blood increasesc.the % of cardiac output is unchanged, and the volume of blood is unchangedd.both systolic pressure generation and stroke volume.

Exercise is associated with alterations to many basic physiological processes, including changes in metabolism and the cardiovascular system.  As the intensity of exercise rises, both the cardiac output and oxygen consumption increase, as shown in Figure 1.Figure 1  Changes in cardiac output and oxygen consumption in response to various levels of exerciseThe cardiac output CO represents the volume of blood pumped by the heart in 1 minute.  The CO is calculated from the heart rate HR and stroke volume SV using the equationCO = HR ∙ SVEquation 1Experimental data has shown that the HR increases linearly with the exercise output Eout, leading to the relationshipHR = 0.65 ∙ Eout + 75Equation 2The metabolism of nutrients consumes oxygen and generates carbon dioxide as a waste product.  The amount of carbon dioxide generated depends on the type of macronutrient that is consumed.  For example, when carbohydrates are metabolized, every liter of oxygen consumed causes the generation of 1.0 liter of carbon dioxide.  Alternatively, the metabolism of fats leads to 0.7 liters of carbon dioxide per liter of oxygen, and the metabolism of proteins generates 0.8 liters of carbon dioxide for each liter of oxygen. Question 56While exercising on a treadmill, a person has a cardiac output of 15 L/min and produces carbon dioxide at 0.091 mol/min.  What is their ratio of metabolizing carbohydrates to fats during the exercise?  (Assume all gasses are ideal and are at STP.)A.1:2B.1:1C.1:0D.2:1Submit

The initial increase in heart rate at the onset of incremental exercise is due to:Group of answer choicesincreased plasma adrenalinereduced vagal activityincreased venous return due to activation of the muscle pump

During exercise, which of the following causes an increased heart rate? parasympathetic stimulation of the atrioventricular node. parasympathetic stimulation of the sinoatrial node. sympathetic stimulation of the sinoatrial node. sympathetic stimulation of the atrioventricular node.