2.6 Flashcards
what is cardiac output
blood pumped through each ventricle per minute
what is cardiac output calculation
CO = HR x SV
what happens during atrial systole
ariel systole transfers the remainder of the blood out through the AV valves to the ventricles
what happens during ventricular systole
ventricular systole closes the AV valves and pumps the blood out through the SL valves to the aorta and pulmonary artery
what happens during cardiac diasyole
blood returns to the atria flows into the ventricles, high pressure in the arteries closed SL valves
state the three steps of the cardiac cycle
- atrial systole, ventricular diastole: blood is pushed into ventricles
- atrial diastole ventricular systole: blood pushed out the heart
- cardiac diastole : blood flows into heart
state the 4 stages of the cardiac conducting system
- impulse is generated in SA node and passes across atria
- the AVN then picks up the impulse from SAN
- passes to bundle of conducting fibres and travels fish the centre of the heart
- impulse branches ~> impulse travels up the ventricle walls causing ventricles to contract
what is the SAN node
it’s located in the wall of the right atrium, set the rate at which the heart contracts, done by the auto rhythmic cells
where is the AVN
the centre of the heart
how can current in the heart be measured
electrocardiogram
in an ECG what does a P wave mean
atrial systole
in a ECG what does the QRS complex mean
ventricular systole
in an ECG what does the T wave mean
ventricular diastole
what does the medulla do
regulates the rate of the SAN through antagonistic action of the ANS
how is the heart rate controlled
the sympathetic nerve releases noradrenaline which increases the heart rate
the parasympathetic nerve releases acetylcholine which decreases heart rate
how is blood pressure measured
using a sphygmomanometer
what is the typical blood pressure reading for a young adult
120/80 mmHg
