Cardiovascular System and Exercise

Question 1

What is the cardiovascular system involved in?

Answer 1

• Transport CO2 and O2
• Supply nutrients
• Waste removal
• Regulate blood flow
• Thermoregulation

Question 2

BP =

Answer 2

Q x TPR

Question 3

What is blood pressure?

Answer 3

The force of the blood during the ejection from the left ventricle
Systolic (stretch of the arteries)
Diastolic (relaxation of the arteries)

Question 4

What is total peripheral resistance?

Answer 4

The resistance to blood flow created by the vascular system

Question 5

What are factors that increase TPR?

Answer 5

Decreased artery radius

Increase viscosity of the blood

Question 6

What is the pulse rate?

Answer 6

The force of the blood during ejection from the left which creates a wave of pressure through the arterial system and can be measured as a pulse.
Accurate measurement: HR = pulse rate

Question 7

What happens to systolic blood pressure during rhythmic exercise?

Answer 7

Increase until max exercise due to increase in Q

Question 8

What happens to diastolic blood pressure during rhythmic?

Answer 8

Stays the same or slightly decreases due to reduced TPR because of vasodilation
At max exercise diastolic pressure may increase slightly due to higher Q and muscle tension

Question 9

What happens to blood pressure above 50% max voluntary contraction?

Answer 9

Systolic increases due to increased TPR

Diastolic may increase with prolonged intense contraction

Question 10

What is the Valsalva Maneuver?

Answer 10

Attempting to exhale with the nostrils and mouth closed
Increases BP
Creates a stable frame for muscle contractions

Question 11

What is the difference between upper and lower body exercise strength exercise at 50% MVC?

Answer 11

Higher BP in arms because of smaller muscle mass and vasculature

Question 12

What is hypertension?

Answer 12

High blood pressure 140/90

Due to increase TPR associated with atherosclerosis, diet, obesity, diabetes, stress, inactivity

Question 13

What is hypotension?

Answer 13

Low blood pressure 90/60

caused by low blood volume, venous pooling, certain medication, endocrine response

Question 14

The heart is…

Answer 14

Very aerobic muscle

• Highly vasculature
• Highly oxygen extraction (70-80% at rest)

Question 15

How does the heart have high aerobic metabolism?

Answer 15

Lots of mitochondria
Highest fat metabolism
High LDH (h) favouring lactate metabolism

Question 16

What is rate pressure product?

Answer 16

Estimation of myocardial work
RPP = BPsys x HR
Beneficial if reduced during exercise

Question 17

What is the control of the heart?

Answer 17

1) Intrinsic pacemaker activity
2) CVC in medulla oblongata coordinates heart function
3) Extrinsic contol
- PNS -> acetylcholine -> decrease HR
- adrenal glands -> epinephrine -> increase HR
4 a) Mechano and chemoreceptors
b) Baro-receptor responds to stretch (inhibitory)

Question 18

What is the intrinsic control?

Answer 18

Sino Atrial Nodes

Question 19

What is the extrinsic control?

Answer 19

Medulla oblongata
-Parasympathetic (slows the HR)
-Sympathetic (increases HR)
Chemorecptors and mechanoreceptors

Question 20

What are the electrical events of the heart?

Answer 20

Effects: the depolarization and repolarization of the atrial and ventricle
Result: coordinated contraction of the heart musculature to allow filling and emptying of blood

Question 21

What can be assessed using ultra sound?

Answer 21

The structure of the heart, coupled with dopler blood flow can also be assessed

Question 22

What directs blood flow?

Answer 22

Vasodilation/contsriction

Question 23

How is vasodilation accomplished?

Answer 23

SNS: Increase acetylcholine from the cholinergic SN = Vasocnstriction to gut
Hormonal: (nor)epinephrine released from adrenal gland
Local auto-regulatory factors: associated with a working muscle trigger vasodilation
-Factors: increase temp, decrease O2

Question 24

How is vasoconstriction accomplished?

Answer 24

These factors do not affect the vessels of the heart or muscle
Sympathetic nervous system: increase norepinephrine release from nerve ending
Hormonal response: (nor)epinephrine from adrenal medulla

Question 25

What is cardiac output?

Answer 25

Volume of blood pumped by the ventricle/min Q=HR x SV Rest= 5L/min

Question 26

How is vasodilation accomplished?

Answer 26

SNS: Increase acetylcholine from the cholinergic SN = Vasoconstriction to gut Hormonal: (nor)epinephrine released from adrenal gland Local auto-regulatory factors: associated with a working muscle trigger vasodilation -Factors: increase temp, decrease O2

Question 27

What is SV?

Answer 27

the amount of blood ejected by the ventricle per beat and depends on: - Pre-load: blood returning to the atria - Size of ventricle - After load: amount force needed to great against back pressure on the heart (TPR)

Question 28

What is the Frank-Starling law?

Answer 28

``` Increase pre-load Increase filling of ventricle Stretching the heart muscle Optimal fiber length Increase force of contraction Increase SV ```

Question 29

What happens to stroke volume during exercise?

Answer 29

Increases up to 40-60% of VO2max

Question 30

Why does it SV plateau?

Answer 30

Preload: decrease in preload time = faster HR with less filling time Contractility: possible cardiac fatigue Afterload: increase in afterload pressure Size of ventricle: unlikely to change during exercise

Question 31

Can we train SV to contribute to increase?

Answer 31

Enhanced pre-load: improved venous return producing an increase in EDV and contractility in elite endurance No reduction in contractility (cardiac fatigue reduced)

Question 32

What happens during submaximal aerobic exercise?

Answer 32

``` HR increase to steady state SV increases but maxes at 50-60% Increase in SBP and no change in DBP Increase in pre-load due to increase blood flow Untrained =100-120ml/bt Trained=160-180ml/bt Elite= 200ml/bt ```

Question 33

What happens during max exercise?

Answer 33

``` Q, HR, SV are all at max SBP increase TPR is at lowest Blood flow increase Preload increase afterload increase Hemoglobin saturation decrease ```

Question 34

What are some general training adaptation at rest?

Answer 34

``` Cardiac hypertrophy (cavity size or wall thickness) Decrease resting HR Increase SV Increase total blood volume Increase capillerization Increase oxidative capacity Decrease BP ```

Question 35

What are training changes at submaximal exercise?

Answer 35

Increase SV at any given PO decrease HR slight decrease in Q Increase a-vO2 diff Decrease SBP No change or slight decrease in blood flow -Increase O2 extraction -Increase mechanical and metabolic efficiency -Improvements in thermoregulation

Question 36

What are training changes at max exercise?

Answer 36

Increase Q due to increase SV Increase max blood flow due to increase Q and decrease TPR Increase in a-vO2diff (increase O2 extraction) SBP same or increase HR same or slightly lower Increase VO2 max

Question 37

What is blood doping?

Answer 37

``` Increase hematocrit Increase hemaglobin content Increase blood volume Increase O2 carrying capacity and delivery of blood Increase VO2 ```

Question 38

What is the modern technique of blood doping?

Answer 38

Erythropoietin (EPO) increased unnaturally increases total amount of RBC Increase in hemoglobin concentration

Question 39

What are EPO complications?

Answer 39

Concentration hematocrit increase likely hood stroke, heart attack Liver dysfunction