Unit 3 Exercise Physiology - Cardiovascular system (2.2)

Question 1

composition of blood (4)

Answer 1

Made of:
* Erythrocytes :Red blood cells - gas transport via hemoglobin
* Leucocytes: White blood cells - immune system
* Platelets: Help clot to prevent bleeding
* Plasma (biggest %): The “liquid” in blood - transports many nutrients

Question 2

Chambers in the heart

Answer 2

• Left atrium
• Left ventricle
• Right atrium
• Right ventricle

Question 3

Valves (4)

Answer 3

• Bicuspid
• Tricuspid
• Aortic valves
• Pulmonary valves

Question 4

Vasculature in the heart: (4)

Answer 4

• Vena cava
• Pulmonary vein
• Aorta
• Pulmonary artery

Question 5

Coronary arteries in the heart (function - 2 + Coronary arteries of the heart - 7)

Answer 5

Function:
* Provide the blood supply to the heart muscle
* The heart muscle cannot use the blood in the heart

Coronary arteries of the heart:
* right coronary artery
* right acute marginal artery
* left coronary artery
* circumflex artery
* left obtuse marginal artery
* left anterior descending artery
* diagonal arteries

Question 6

explain double loop circulation

Answer 6

Pulmonary circulation
* Heart to lungs to heart
* Get oxygen and release Co2 from gas exchange in lungs

Systemic circulation:
* Heart to body to heart
* Deliver oxygen to tissues that need it
* Transport nutrients and waste around the body

Question 7

Heartbeat (7)

Answer 7

• Needs to be synchronized for a efficient pump of blood
• Atrium needs to empty into the ventricle.
• Ventricle needs to push into the artery.
• Both left and right sides of the heart are doing the same thing at the same time
• SA node: pacemaker
• SA is a special bundle of heart cells
• AV node ensures delay, proper filling and direction of contraction

Question 8

regulation of heartbeat (intrinsic -2 + extrinsic control-1)

Answer 8

Intrinsic control:
* The heart can beat without any nerve or chemical impulses due to its myogenic property
* Can self contract but this can be unsynchronized

Extrinsic control:
* Chemical, nerve or hormonal control to change heartbeat

Question 9

Pace of heartbeat (speeding up/slowing down)(4)

Answer 9

• The brain sends nerve impulses from the medulla to the SA node of the heart
• The sympathetic nerve increases heart rate
• The parasympathetic nerve decreases heart rate
• Epinephrine (Adrenaline) is a hormone produced by the adrenal gland that works on the SA node to increase HR

Question 10

heart response during warm up of activity (6)

Answer 10

As the body starts to increase activity CO2 increases
* Chemoreceptors detect an increase in CO2

Other receptors observing the start of activity:
* Baroreceptors detect an increase in blood pressure
* Proprioceptors detect an increase in muscular movement

Nervous system response:
* Information is received by the medulla oblongata
* The sympathetic nervous system sends a signal to the SA node
* SA node increases firing to increase HR

Question 11

Type of blood pressure

Answer 11

Systolic: the force exerted by blood on arterial walls during ventricular contraction

Diastolic: the force exerted by blood on arterial walls during ventricular relaxation

• Blood pressure = systolic/diastolic
• Avg blood pressure =120/80

Question 12

What is Cardiac output - 2

Answer 12

a measure of the amount of blood pumped in a set amount of time (usually a minute)

CO = stroke volume x heart rate

Question 13

what is stroke volume

Answer 13

volume of blood pumped in one heart beat

Question 14

Relationship between HR, cardiac output, stroke volume at rest and during exercise

Answer 14

Relationship: Both HR and SV have a direct relationship with cardiac output
* Increase HR/SV = increase in CO

During exercise: HR and SV go up so CO goes up

Rest: HR and SV stay the same so CO stays the same

Question 15

Blood pressure response to dynamic exercise - what-2, why-3

Answer 15

What is happening:
* Stroke Volume is increasing to meet oxygen demands
* Muscles are contracting and relaxing which squeezes and releases vasculature

What this causes to BP:
* Systolic pressure increases as more blood is being pushed with each contraction
* Continues to increase proportionally as exercise intensity increases
* No or little change to diastolic compared to rest due to a decrease in total peripheral resistance

Question 16

blood pressure response to static exercise - what-2, why-2

Answer 16

What is happening:
* Muscles are contracting isometrically
* Constant compression of the vasculature

What this causes to BP:
* Systolic Pressure increases substantially compared to rest due to the narrowing of the vasculature
Diastolic pressure increases compared to rest as the muscles never relax, causing sustained narrowing of vasculature

Question 17

Cardiovascular drift

Answer 17

Prolonged submaximal progressive increase in heart rate and decrease in stroke volume that begins after approximately 10 min of prolonged moderate-intensity exercise

Question 18

how to combat (2) and prevent (3) cardiovascular drift

Answer 18

To combat:
* HR increases to maintain CO
* Vasodilation of blood to working muscles

Prevention:
* Hydrate
* Exercise during cooler times a day
* Decrease intensity

Question 19

Cardiac output response to exercise: during exercise-3, long term exercise-2, prevention-2

Answer 19

During exercise:
* Cardiac output would increase
* HR and SV increases to maintain the CO increased
* Both increase to meet the oxygen demands of the exercising tissue

Long term exercise
* HR must increase due to: Decreased SV from cardiovascular drift
* Rise in body temp–> diversion of blood flow to the skin to cool the body causes a decrease in flow to working muscles

Prevention:
* Hydrate to maintain blood volume
* Electrolytes to maintain osmotic balance leading to increased blood volume

Question 20

how age affects heart rate (3)

Answer 20

As you increase with age you maximum possible HR decreases
* This means you are closer to max HR, cannot increase as much
* Your heart becomes less sensitive to epinephrine –> less ability to increase HR

Question 21

how gender affects HR(1), cardiac output(1) and stroke volume(4)

Answer 21

SV:
* Females have reduced stroke volume compared to males
* A female heart is smaller than a males heart even if size of participant is controlled
* Have thinner heart muscle too
* Less blood can be pumped per beat

HR:
* Gender does not affect max HR, females have slightly higher HR due to lower SV

CO:
* Cardiac Output is lower in females than males

Question 22

how training affects HR, SV and CO - 4

Answer 22

Individuals who have been training have the following compared to untrained individuals:
* Lower resting HR as they are more efficient at O2 delivery (more RBC)
* Higher possible SV as heart is better trained to pump
* Higher max CO - as SV is increased and max HR is not impacted by training

For submaximal effort - same CO but trained will have a lower HR, with higher SV

Question 23

VO2 (maximal energy consumption): (5)

Answer 23

What is VO2:
* Maximum volume of oxygen inhaled and used per minute.
* Way to measure fitness
* Maximum volume (mL) of oxygen one can use in one minute per kilogram of body weight. mL/min/kg
* Those who are ‘fitter’ have higher VO2 max values and can exercise more intensely than those who are not as well conditioned.
–> They can get more oxygen to their muscles to perform better

Question 24

how VO2 changes based on age - 3

Answer 24

• Increases through youth as physical maturity and development improves
• Peaks around 20 for males and late teens for females decreases past 20
• Training can reverse this trend

Question 25

how VO2 changes based on training -3

Answer 25

• Training increases your VO2 max as your cardiac output improves.
• You are able to move more oxygen around.
• See less improvement as training increases. Non-trained individuals see lots of improvement. Trained individuals need to work a lot harder for gains.

Question 26

how VO2 changes based on gender 4

Answer 26

Higher in males due to:
* higher Cardiac Output
* Females have a larger % fat in body mass
* Females have a lower hemoglobin concentration (10–14 % more in males), less ability to transport oxygen in blood

Question 27

how vo2 max changes based on exercise
- 4 examples

Answer 27

VO2 Max changes based on the exercise used to find the value. The less muscles involved in the exercise, the lower the VO2 Max.
* Cross country skiing - highest as upper and lower body involved
* Cycling - requires the most muscle force and will have the highest possible VO2 Max found
* Running- Close to cycling but a little less
* Hand Ergometer - lowest as only the arms are used, 70-80% of the others types

Question 28

Blood movement during exercise (be able to compare the distribution of blood at rest and the redistribution of blood during exercise): -7

Answer 28

• Blood flows towards working muscles
• The sympathetic nervous system focuses blood towards the working muscles and away from our digestive organs.
• Blood flow to the brain remains unchanged.
• Arteries traveling to the working muscles vasodilate to allow more blood flow.
• Arteries towards the digestive organs vasoconstrict to reduce blood flow.
• Blood flow can increase to skin to help cool the body.
• Blood flow to the heart muscle remains the same.