Exercise: Pathophysiology and Testing

Question 1

Describe the Fick principle.

Answer 1

The Fick principle gives amount of blood extracted by the tissues per time. The equation for it is (arterial O2 - venous O2) x cardiac output

Question 2

During exercise, blood diverts from the _____ to the _______.

Answer 2

organs; muscles

Question 3

Cardiac output in early exercise is increased by ____________.

Answer 3

withdrawal of the parasympathetic input

Question 4

Cardiac output in late exercise is increased by _____________.

Answer 4

sympathetic stimulation

Question 5

What leads to increased venous return?

Answer 5

Vasoconstriction (in non-exercising tissues like organs), muscles pumping veins, and negative thoracic pressure

Question 6

Catecholamines include __________.

Answer 6

norepinephrine and epinephrine

Question 7

Endurance athletes have a ________ shift in the Frank-Starling curve.

Answer 7

leftward

Question 8

Endurance athletes have a higher _________ at rest.

Answer 8

stroke volume

Question 9

Greater blood flow occurs during exercise due to __________.

Answer 9

decreased vascular resistance

Question 10

Blood flow during exercise does not depend on ___________.

Answer 10

blood viscosity

Question 11

Why is diastolic blood pressure a better indicator of health?

Answer 11

Because systolic pressure depends largely on ventricular contraction–which can change–but diastolic blood pressure depends on vascular compliance and relaxation.

Question 12

How is vaso-regulation different in organs and muscle during exercise?

Answer 12

In organs, vasoconstriction occurs due to input from the sympathetic nervous system, while in muscles vasodilation occurs due to autoregulation.

Question 13

During exercise, the arteries have the same level of initial __________.

Answer 13

oxygen

Question 14

What is mixed venous oxygen saturation?

Answer 14

Mixed venous oxygen saturation is the oxygen saturation of the blood in the pulmonary arteries. It is called “mixed” because it is from different tissues.

Question 15

The rate-pressure product (RPP) is influenced mostly by ___________.

Answer 15

chronotropic work

Question 16

Stroke volume and heart rate are dependent on exercise status. At high heart rates during exercise, stroke volume ________, while at rest stroke volume ___________.

Answer 16

increases (because of venoconstriction); decreases (because of decreased filling time)

Question 17

Stroke volume is greater when ________.

Answer 17

lying down

Question 18

______ L/min of cardiac output are required above baseline for every increased 1 L/min oxygen used.

Answer 18

6

Question 19

There is no difference between __________ at rest.

Answer 19

cardiac output between trained and untrained people

Question 20

During exercise, the absolute blood flow to the brain ________, while the percent of blood in the body that goes to the brain ________.

Answer 20

increases; decreases

Question 21

Give the Fick equation.

Answer 21

O2 used = cardiac output x (arterial O2 - venous O2)

Question 22

Ischemia effectively lowers the ______ at which ST-depression occurs.

Answer 22

RPP