Ex Phys

Question 1

Cardiac Output (Q) equation
What happens during exercise?

Answer 1

Q = HR × SV
During exercise, Q increases due to an increase in HR and SV

Question 2

What happens to Total Peripheral Resistance (TPR) during exercise?

Answer 2

During exercise, your total peripheral resistance decreases due to vasodilation

Question 3

What happens to your Mean arterial pressure (MAP) during exercise?

Answer 3

During exercise, your MAP increases slightly to ensure an increase in oxygen delivery to the muscles

Question 4

The role of venous system
What happens during exercise and without movement?

Answer 4

It acts as an active blood reservoir. The muscle pump and the respiratory pump increase venous return. Without movement, you have venous pooling, which leads to a decrease in venous return, leading to a reduction in SV and CO. This leads to dizziness/fainting in some.

Question 5

Resting BP vs. Exercise BP

Answer 5

Rest: ~120/80 mmHg. Moderate aerobic: SBP increases to ~140–160 while your DBP remains unchanged.
Intense aerobic: SBP may reach 200+, DBP stable or ↓ slightly.

Question 6

Graded Exercise BP
Response

Answer 6

SBP rises linearly with intensity. DBP remains stable or decreases slightly. Reflects an increase in CO and a decrease in TPR.

Question 7

Steady-State Exercise BP
Response

Answer 7

Initial SBP ↑, then levels off or ↓ as vasodilation reduces TPR. DBP remains stable.

Question 8

Upper-Body vs. Lower-Body
Exercise BP and why

Answer 8

At the same %VO2 max, arm work = ↑ SBP and DBP vs. leg work.
Reason: smaller
muscle mass and vasculature → ↑ resistance.

Question 9

Resistance Exercise BP
Response

Answer 9

Vessel compression ↑ TPR → very high BP (e.g., >300/200 mmHg). Valsalva further
↑ BP. Caution for individuals with CV disease.

Question 10

Recovery from Exercise BP

Answer 10

Post-exercise hypotension: BP falls below pre-exercise levels for up to 12 hrs.
Caused by vasodilation. Supports exercise as therapy for hypertension.

Question 11

Heart Failure Pathophysiology (systolic vw diastolic

Answer 11

Systolic dysfunction: dilated Left ventricle, poor contraction, ↑ EDV, ↓ EF%. Diastolic dysfunction: stiff LV, poor filling, ↓ EDV, normal/increased EF%. Both limit exercise
tolerance.

Question 12

How do the sympathetic and parasympathetic divisions regulate cardiovascular function in exercise?

Answer 12

Sympathetic: ↑ heart rate (HR), ↑ contractility, ↑ vasoconstriction (except in active muscle, where vasodilation dominates).
Parasympathetic: Predominant at rest, ↓ HR via vagus nerve. Withdraws quickly at exercise onset.

Question 13

What role does central command play in exercise HR response?

Answer 13

Provides the fast “turn-on” of HR at exercise onset by ↓ parasympathetic inhibition and ↑ sympathetic activation.
Explains how emotions/anticipation (e.g., pre-race anxiety) can elevate HR even before movement begins.

Question 14

What signals fine-tune cardiovascular regulation during exercise?

Answer 14

Mechanoreceptors (Type III): detect muscle stretch and force.

Chemoreceptors (Type IV): detect metabolic by-products (H+, CO₂, K+).

Baroreceptors (aortic arch & carotid sinus): sense ↑ BP → reflex ↓ HR & vasodilation.

Cardiopulmonary receptors: sense filling in heart and large veins → help regulate blood return and pressure.

Question 15

What role does nitric oxide (NO) play in exercise?

Answer 15

Causes vasodilation → improves blood delivery to active muscle.

Question 16

What physical factors determine blood flow?

Answer 16

Vessel radius (most powerful factor; Poiseuille’s Law: resistance ∝ 1/radius⁴).

Question 17

How is blood redistributed during exercise?

Answer 17

Rest: ~20% of cardiac output (CO) goes to muscle.

Exercise: 85–90% of CO goes to active muscle.
In trained athletes, redistribution begins before exercise (anticipatory response).

Question 18

What is the Fick Equation and why is it important?

Answer 18

VO₂ = Q × (a-vO₂ difference)
Explains that oxygen delivery and extraction determine exercise capacity.

During max exercise, both Q and a-vO₂ diff increase.

Question 19

How does HR response differ in transplant patients?

Answer 19

Resting HR elevated (~100+ bpm) due to loss of vagal tone.
HR increase during exercise is slower (no direct neural input, vagus nerve)

Question 20

Conducting Zone

Answer 20

Trachea → bronchi → bronchioles → terminal bronchioles (no gas exchange)

Question 21

Respiratory Zone

Answer 21

Respiratory bronchioles → alveolar ducts → alveoli (gas exchange occurs here)

Question 22

Why does airflow slow in the terminal bronchioles?

Answer 22

Because the total cross-sectional area increases, allowing time for efficient gas exchange, crucial during high cardiac output in exercise.

Question 23

How much VO₂ can respiratory muscles use during intense exercise?

Answer 23

Up to 10–15% of total VO₂.

Question 24

What happens to tidal volume (TV) during moderate exercise?

Answer 24

It increases up to about 60% of vital capacity before breathing frequency rises further.

Question 25

What does a high MVV indicate in an athlete?

Answer 25

Strong ventilatory muscle capacity

Question 26

Formula for VE?

Answer 26

VE = Breathing Frequency × Tidal Volume

Question 27

What happens to VE at ventilatory threshold (VT)?

Answer 27

VE rises disproportionately to VO₂ because of CO₂ production from lactate buffering.

Question 28

Typical VE during maximal exercise?

Answer 28

Can exceed 150 L/min (even >200 L/min in elite endurance athletes).

Question 29

What happens to muscle PO₂ during maximal exercise?

Answer 29

It may fall close to 0 mmHg, which increases O₂ diffusion into muscle.

Question 30

How does anemia affect exercise performance?

Answer 30

Reduces O₂ carrying capacity → ↓VO₂max and early fatigue.

Question 31

What causes the rapid rise in ventilation at the start of exercise?

Answer 31

Neurogenic input from the motor cortex + muscle/joint receptors (before chemical changes).

Question 32

What do peripheral chemoreceptors respond to?

Answer 32

↓PO₂, ↑PCO₂, ↑H⁺ — they increase ventilation to maintain homeostasis.

Question 33

What does a higher ventilatory threshold indicate?

Answer 33

The athlete can sustain higher workloads before hyperventilation and fatigue.

Question 34

What happens to pH during heavy exercise?

Answer 34

pH drops (acidosis), stimulating ventilation; extreme exercise may cause pH ≤ 7.0 → nausea, dizziness.

Question 35

What usually limits VO₂max — lungs or heart?

Answer 35

The cardiovascular system (cardiac output), except in some elite athletes who may have diffusion limitations.

Question 36

How much VO₂ can respiratory muscles use during maximal exercise?

Answer 36

Up to 10–15% of total VO₂.

Question 37

What happens to tidal volume (TV) during exercise?

Answer 37

TV rises until ~60% of VC, then breathing frequency increases to meet demand.

Question 38

What does MVV measure, and what does it predict?

Answer 38

Max voluntary ventilation — reflects ventilatory muscle capacity. High MVV = better exercise tolerance

Question 39

Typical VE during maximal exercise?

Answer 39

Can exceed 150–200 L/min in well-trained athletes.

Question 40

What does a widened a-vO₂ difference indicate?

Answer 40

Greater O₂ extraction by tissues — seen in exercise or with training.

Question 41

What usually limits VO₂max in healthy people?

Answer 41

Cardiac output (central limitation), not lungs.

Question 42

Difference between VO₂peak and VO₂max?

Answer 42

VO₂peak = highest VO₂ achieved but may not reach true physiologic max (no plateau). VO₂max = plateau in VO₂ despite increasing workload

Question 43

Effect of endurance training on VO₂max?

Answer 43

Increases VO₂max by improving SV, CO, and a-vO₂ diff.

Question 44

What is CPET used for?

Answer 44

To measure integrative cardiorespiratory function (O₂ uptake, CO₂ output, HR, VE) and detect limitations (cardiac vs pulmonary vs muscular).

Question 45

What does RER > 1.1 during CPET indicate?

Answer 45

Near-maximal effort and high anaerobic metabolism.

Question 46

What happens to HR response after cardiac transplant (HTX)?

Answer 46

Resting HR ↑, but peak HR response is blunted; CO rises more via ↑SV.

Question 47

What happens to resting HR and submax HR after training?

Answer 47

Both ↓ due to increased stroke volume.

Question 48

What happens to stroke volume after training?

Answer 48

↑ at rest, submax, and max → ↑CO and VO₂max.

Question 49

What happens to VE at submax exercise after training?

Answer 49

VE ↓ because breathing frequency is lower and tidal volume is more efficient.

Question 50

How does ventilatory threshold change with training?

Answer 50

Shifts to a higher workload — athlete can stay aerobic longer.

Question 51

Does resistance training increase VO₂max much?

Answer 51

No, primary adaptations are muscular strength, not large VO₂max gains.

Question 52

Acute physiologic response difference between aerobic and resistance exercise?

Answer 52

Resistance → higher blood pressure spikes; Aerobic → steady HR/VO₂ rise