The Heart Flashcards
What is the equation for cardiac output
Cardiac output (Q)=Stroke Volume (SV) x Heart rate (HR)
Define cardiac output
the volume of blood that leaves the left ventricle per minute
Define stroke volume
the volume of blood that leaves the left ventricle per contraction
Define heart rate
the number of heart contractions per minute
What is anticipatory rise and what is the hormone that causes it
A nticipatory rise is an increase in heart rate before exercise caused by the release of adrenaline into the blood
The adrenaline release stimulates the SA to increase heart rate
Why do experienced athletes have a higher cardiac output and quicker recovery than untrained athletes
-cardiac hypertrophy (higher stroke volume)
-bradycardia
-higher end diastolic volume
What is steady state exercise
-When the demand for oxygen is being met with an equal supply of oxygen
-exercise at a constant heart rate
What is a rapid increase and steep decline in heart rate
Rapid increase-a quick increase in HR as exercise begins
Steep decline-a quick decrease in HR as exercise finishes
Describe the stimulation of the heart
An impulse begins in the Sino-atrial node in the right atrium and then passes across to the left atrium to cause atrial systole
The impulse is then received by the Atro-Ventricular node between the right atrium and right ventricle which relays the signal,where it is later passed onto the Bundle of His which is in the Septum
The septum separates the signal into left and right
The signal then passes down the septum as two separate signals into the purkinje fibres in the ventricular walls
The purkinje fibres spread out the signal to every cell causing ventricular systole
What is the ‘All or None Law’
The heart either contracts fully (systole) or doesnt contract at all (diastole)
Define the terms systole and diastole
Systole-the phase in which the heart contracts and ejects blood
Diastole-the phase in which the heart relaxes and fills up
When the atrium goes through systole,the ventricle goes through
diastole
When the ventricle goes through systole,the atrium goes through …
diastole
