Nalua Flashcards
The Heart
1
Q
the three stages of the cardiac cycle
A
- atrial systole
- ventricular systole
- cardiac diastole
2
Q
what structures produce electrical activity in the heart
A
- SAN
- AVN
- bundle of His
- purkyne fibres
3
Q
what is meant buy the term ‘myogenic’?
A
it can contract and relax without receiving signals from neurones
4
Q
the role of the SAN
A
- initiates depolarisation
- which passes through atria
- causes atrial systole
5
Q
role of AVN
A
- conducts wave of depolarisation to the venricles
- passes it to the bundle of His
6
Q
role of the bundle of His
A
- conducts the waves of depolarisation from the AVN down to the purkyne fibres
7
Q
role of purkyne fibres
A
- turns wave of depolaristaion into a contraction of the ventricle
- causing ventricular systole
8
Q
What does ECG stand for
A
ElectroCardioGram
9
Q
How does an ECG work
A
- records the electrical activity of your heart (rhythms produced by electrical activity)
10
Q
what is an ECG used for
A
- to diagnose cardiovascular diseases
11
Q
P wave
A
contraction (depolarisation) of the atria
–> atrial systole
12
Q
QRS complex
A
contraction (depolarisation) of ventricles
–> ventricular systole
13
Q
T wave
A
relaxation (repolarisation) of the ventricles
–> cardiac diastole
14
Q
Tachycardia
A
- heartbeat is too fast
- as heart cant pump blood efficiently :. heart rate increases to ensure enough blood is pumped around the body
