Lecture 38 - Exercise Physiology

Question 1

Which of the two, isotonic or isometric exercise, means movement is occurring?

Answer 1

Isotonic –> movement

Question 2

Isotonic exercise increases the ______ (volume or pressure?) load on the heart, while Isometric increases the ______ (volume or pressure?) load.

Answer 2

Isotonic –> increases volume load

Isometric –> increases pressure

Question 3

How does CO, O2 consumption, and Systemic Vascular Resistance change in isotonic vs isometric exercise?

Answer 3

Isotonic –> CO increases, O2 consumption increases, but SVR decreases

Isometric –> CO and O2 consumption are relatively unchanged, but SVR increases (think increased pressure load).

Question 4

The ______ ______ is the control center for the Autonomic Nervous system in the Brain. ______ fibers run down the spinal cord and exit via the thoracolumbar distribution. They synapse at ______ chain ganglia and innervate organs, including the heart, peripheral vasculature, and adrenal glands. The adrenals secrete epi and norepi.

The parasympatheic system works outside the spinal cord via the ____ nerve, which directly innervates the heart and adrenal glands.

Answer 4

Madulla Oblongata

Sympathetic

Sympathetic chain ganlgia

Vagus nerve

Question 5

Mean Arterial BP = ______ X _______

Answer 5

Cardiac output X Systemic vascular resistance

Question 6

Remember that ______ BP typically does NOT increase during exercise.

Answer 6

Diastolic

Question 7

The heart will experience maximal venous return and thus stroke volume when the body is in what position? Keep in mind normal stroke volume is about ____-____mL/beat.

Answer 7

When the body is laying down.

50-70mL/beat

Question 8

Well trained athletes will have enhanced ______ tone at rest, which should make sense bc they have a greater _____ volume (about 90-110mL/beat).

Answer 8

Vagal tone

Stroke volume

Question 9

How does the body react in anticipation of exercise (just the thought of it)?

Answer 9

Sympathetic tone will increase, and all that comes with it.

Question 10

Orthostatic Hypotension is defined by any one of the following:

Systolic BP decreases by > _____mmHg

Dastolic BP decreases by > _____mmHg

Heart Rate Increases by > _____ bpm

Answer 10

20mmHg

10mmHg

20bpm

Question 11

At the onset of exercise, the increase in Heart Rate is initially induced by a decrease in ________ tone.

Answer 11

Parasympathetic tone

Question 12

As exercise intensity increase toward maximal effort, is increase in Stroke volume or Heart rate more responsible for the increase in CO?

Answer 12

As exercise intensity increases, Heart rate becomes the key factor for increasing CO bc stroke volume can only increase so much via increased venous return.

Question 13

Maximal heart rate is estimated as _____ bpm minus the patient’s age.

Answer 13

220bpm

Question 14

The heart can reach a steady state during exercise of unchanging intensity, but after a prolonged period, even if the intensity remains unchanged, the heart will experience Cardiac _____ (the rate increases due to increase in core body temp.)

Answer 14

Cardiac Drift

Question 15

_______ Incompetence refers to a heart’s inability to reach 85% of the maximal rate.

Answer 15

Chronotropic Incompetence

Question 16

How does O2 extraction change for the heart and brain during exercise vs other organs?

Answer 16

The heart and brain typically extract maximal O2 at rest and continue to do so during exercise (so their ability to receive nutrients is Flow dependent). Other organs can increase the amout of O2 they extract, while their blood flow decreases during exercise.

Question 17

During exercise, plasma volume ______ (increases or decreases?) as a result of increased systolic BP. In turn, ______ concentration is effectively increased.

Answer 17

Decreases (basically pushed out)

Hb

Question 18

Following Exercise, Systolic BP falls below baseline levels for up to ____ hours bc the systemic vascular _______ will take a while to return to normal (the vasodilation in skeletal muscle persists.)

Answer 18

12 hours

Vascular Resistance