Cardiac Cycle Flashcards
What is Cardiac Output?
The volume of blood leaving 1 ventricle in 1 minute.
What is the formula for cardiac output? Include units.
Cardiac output = heart rate (min-1) x stroke volume (dm3)
What is heart rate and stroke volume?
Hear rate is beats per minute and stroke volume is the volume of blood leaving the heart each beat.
What does SAN stand for and where is it located?
Sinoatrial node in right atrium.
What does AVN stand for and where is it located
Atrioventricular node near the border of the atria and ventricles.
Where does the Bundle of His run through?
It runs through the septum of the heart.
Where are the purkyne fibres and what is their role?
They are in the ventricle walls and carry on the wave on depolarisation from the Bundle of His into the ventricles, causing ventricular systole.
What is an ECG and what does it measure?
An ECG is an electrocardiogram that measures depolarisation waves of the heart. It does this indirectly by measuring the electrical activity in skin (caused by electrical activity in heart) using electrodes stuck to the skin.
It is used to diagnose and recognise irregular heart rhythms.
List the 4 terms associated with types of irregular heart rhythm.
- Tachycardia
2.Bradycardia
3.Fibrillation
4.Ectopic Heartbeat
What is tachycardia?
Heart beat over 100bpm. Normal only during exercise not at rest.
What is Bradycardia?
Heart beat less that 60bpm. Many athletes have it as they’re cardiac muscle can contract harder so less are needed. If rate is too low, artificial pacemaker is needed to regular heart.
What is fibrilation?
Irregular rhtythm of the heart.
What is an ectopic heartbeat?
Additional heartbeats not in rhythm. Common to occur once a day but more regularly could indicate serious health condition.
