Cardiac Cycle Flashcards
Define blood pressure
The force of blood against arteries
What is the cardiac cycle
The event of one heart beat
What is the resting HR of an untrained performer
70bpm
What is the Resting HR of a trained performer
40bpm
What is heart rate
The number of ventricular contractions per minute
What is stroke volume
The volume of blood pumped from heart in each beat
What is the SV of an untrained performer
70ml
What is the resting SV of a trained performer
100ml
What is cardiac output
SV X HR
What is the cardiac output of untrained and trained performers
5l/m
When does SV reach maximal levels
Iight - moderate intensity
What is diastole
The period of time where the heart relaxes and fills with blood
What is Venus return
How blood is returned to the heart
What is systole
Blood being ejected from the atrium
Why might stroke volume decrease as intensity increases to maximal intensity
As there is not enough time for diastole
What is the range for SV during submaximal intensity
120-200
What is the role of the Sino Atrial Node
To create its own cardiac impulse
Send cardiac impulses around walls of atria
What is atrial stystole
The cardiac muscles recieving an impulses and contracting
What is ventricular diastole
The ventricles filling with blood and relaxing
What is the role of the AV node
To delay the impulse so diastole can occur
What is ventricular systole
Ventricles contract and blood is ejected from the heart
What is the cardiac control centre
The part of the brain that regulates cardiac output
What does the sympathetic nervous system do
Increases heart rate via accelerator nerve
What does the parasympathetic nervous system do
Decreases HR via vagus nerve
What is the role of chemo receptors
Detect change in blood pH
What is the role of baroreceptors
Detect change in blood pressure
What is the role of propio receptors
Detect change in muscle tension
What is the effect of adrenaline
Increases HR by stimulating SA node
Describe instrinsic change
How the heart detects its own changes such as temperature and contractivity
What is the ANS
Autonomic nerve system
Explain how neural control of the heart helps maintain the supply of oxygen during excercise
– Neural control is managed by ANS which uses SNS to increase or decrease HR
– Chemo receptors detect change in blood pH
–information is sent to CCC
– CCC sends nerve impulses via accelerator nerve
– HR increases due to stimulated SA node
– Cardiac output increases
Explain how hormonal regulate of the heart during exercise
Hormonal control is controlled by ANS
Adrenal is secreted by adrenal glands
Stimulating the SA node
Resulting in an increase of HR
And increase of muscular contraction increasing SV
So cardiac output increases
Explain the intrinsic mechanism that controls cardiac output
Increase rate of Venus return, increasing SV
More blood in heart causes atrial walls to stretch stimulating SA node which increases HR
End diastole volume increased stretching walls of LV so ventricles contract with more force causing SV to increase
Cardiac output increases
Resulting in more oxygenated blood
What is the vascular shunt mechanism
The redistribution of blood to working muscles
At rest how much blood goes to organs
80-85%
At rest how much blood goes muscles
10-15%
During excercise how much blood goes to organs
10-15%
During excercise how much blood goes to muscles
80-85%
What is the conduction system
How electrical impulses work in the heart
