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P.E- Anatomy And Physiology > The Heart > Flashcards

Flashcards in The Heart Deck (41)
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1
Q

What are the 3 stages of the cardiac cycle?

A

Diastole
Atrial systole
Ventricular systole

2
Q

What is diastole?

A

Relaxation phase lasts 0.5 seconds
Both atria fill with blood. AV valves closed
Atrial pressure rises above ventricular pressure
Rising blood pressure forces AV valves open and blood passively passes into both ventricles.
Semi lunar valves closed

3
Q

What is atrial systole?

A

Lasts 0.3 seconds
Contraction of left and eight atria
Rising atrial pressure forces remaining blood into the left and right ventricles
Semi lunar valves remain closed

4
Q

What is the ventricular systole?

A

Contraction of both left and right ventricles
Increases ventricle pressure reforming blood out of left and right ventricles
Aortic and pulmonary valves forced open
AV valves closed
Blood forced out into:
Aorta to body tissues
Pulmonary arteries to lungs
40/50% blood ejected at rest during ventricular systole

5
Q

What does the conduction system do?

A

Controls the cardiac cycle

6
Q

How does the conduction system control the cardiac cycle?

A

Control is regulated via an electrical impulse called the cardiac impulse

7
Q

What does myogenic mean?

A

Generates its own cardiac impulse

8
Q

What is the heart rate?

A

Number of heart beats per minute

9
Q

What is stroke volume?

A

The volume of blood ejected from the heart ventricles in 1 beat

10
Q

What is the average resting heart beat?

A

70-72 beats per minute

11
Q

What is cardiac output?

A

The volume of blood ejected by the heart per minute

12
Q

What may indicate high aerobic fitness?

A

A low rating hr and rapid hr recovery after exercise

13
Q

What hr is bradycardia?

A

Below 60 bpm

14
Q

What affects the resting heart rate?

A

Hyper trophy: increase in sv due to an increase in size and strength of the heart muscle wall
Affected by environmental conditions such as articulate and temperature- low= decrease

15
Q

What is maximum heart rate?

A

The highest heart rate value in can achieve in all out effort to the point of exhaustion

Estimated 220- age in years

16
Q

Indications of a steady state/ sub maximal hr

A

Heart rate plateau reached during constant rate of sub maximal work
Aerobic work where O2 supply= muscular demand
It is the optimal heart rate for meeting circulatory demands at that rate of work
The lower the steady star heart rate, the more efficient the heart

17
Q

What is sv?

A

Difference in volume of blood in the ventricles before and after ventricular contraction

18
Q

What is edv?

A

End diastolic volume: volume blood left in the ventricles at the end of the diastole

19
Q

What is esv?

A

End systolic volume: volume blood left in the ventricles at the end of the systole

20
Q

How can sv be calculated?

A

Edv - esv

21
Q

How to calculate cardiac output

A

Stroke volume ( millimetres per min) x heart rate (bpm)= cardiac output (litres per minute)

22
Q

How many litres of blood is pumped out of the heart every minute?

A

5 litres

23
Q

Where is the greatest percentage of cardiac output distributed during resting conditions?

A

Organs

Only 20% to the muscles

24
Q

In relation of their overall mass compared to the percentage of cardiac output distributed to the kidneys and that distributed to the muscles

A

Percentage distr used to the kidneys is the same as the muscles yet kidneys are very small compared to muscle mass

25
Q

Why is the distribution of cardiac output muscles so low during resting conditions despite the larger surface area of muscle!

A

During rest muscles are mostly inactive and do not require a large percentage of cardiac output to supply the oxygen for their energy supply

26
Q

What are the events of a heart beat?

A

Consists of 2 phases lasting 0.8 seconds
1. Diastole relaxation phase during which the chambers fill with blood
Systole contraction phase when Attica and ventricles chambers contract to expel blood

27
Q

Resting values exercise

A

SV: 60/80 ml untrained
80/100 ml trained

HR: 70/72 untrained
60 or below trained

Q 5 L/ min

27
Q

Sub maximal values exercise

A

SV: 80/100ml untrained
160/200 ml trained

HR: 100/130 bpm untrained
Up to 160 bpm trained

Q: 10 to 20 L/min

28
Q

Maximal values exercise

A

SV: 100/120 ml untrained
160/ 200 ml trained

HR: 220- age. Trained= closer U= below

Q: 20/40 L/ min untrained
25 L/ min trained

29
Q

Heart rates at rest

A

Untrained: 70 bpm
Trained: 50 bpm, also known as an athletes pulse

30
Q

Stroke volume at rest

A

Untrained: 71 ml
Trained: 100 ml

31
Q

Cardiac output at rest

A

Untrained: 4970 ml
Trained: 5000ml

Convert in to Litres!!!!!!!

32
Q

Systolic blood pressure resting value

A

100-130 mmHg

33
Q

Diastolic blood pressure resting value

A

70-90 mmHg

34
Q

How does an increase in blood increase cardiac output?

A

More blood returning to the heart
Increased stretch of the atrial wall
Increased EDV
Causing greater force of contraction during ventricular systole
As stroke volume increases more blood is pumped out of the heart per beat
Q= HR X SV, therefore Q increases
More blood returning to the right atrium, stimulated the SA node which increases HR
More or faster blood pumped to working muscles

35
Q

How does an increase in blood flow increase performance?

A

Increased time or intensity for exercise

Delays fatigue or OBlA

36
Q

Starlings law

A

Venous return increases during exercise resulting in more blood returning to the heart
A greater EDV stretches and enlarges the ventricles
Greater stretch and recoil increases the force of ventricular contraction
This increases ventricular contractility almost completely emptying the EDV and increasing SV

37
Q

Heart rate response to exercise

A

HR increases above resting values prior to exercise starring- anticipatory rise
Due to a release in adrenalin
Adrenalin in blood stimulates the SA node to increase HR
HR increases/ in line with exercise intensity- linear relationship
May plateau during sub-maximal work representing a steady state optimal HR to meet the demand for oxygen
HR slow down just prior to maximal HR values

38
Q

Heart rate after exercise

A

HR decreases rapidly after exercise stops
Due to decreased muscular demand for oxygen
More gradual and slower decrease in HR towards resting HR values
Elevated HR during recovery is termed the oxygen debt
More intense the exercise the greater the oxygen debt and therefore the longer the HR recovery

39
Q

Hearts response to an BAHL

A

Hypertrophic: increase resting HR by increasing SV to maintain the same Q at rest and increase potential Q to supply oxygen during exercise
More efficient and healthy heart, bradycardia is under less strain at rest and over period of ones lifetime slows down the hearts deterioration in efficiency due to natural ageing process
May improve the length of an individual’s QoL in relation to sustaining a more active and healthy lifestyle
Increased potential intensity of physical activity

40
Q

Consequences of bradycardia and excessive training

A

HR lower than 40bpm- may not pump enough blood, fainting and develop longer ventricular pauses
Increased risk of developing heart block which sometimes require pace makers to be implanted