Electrical impulases of the heart Flashcards
Define the coduction cardiac cells properties
electrical cells
- 1%of cariac cells
- low actin + myosin pushed to edges of cells
- low stirations
- intercalated disks = high gap junctions
How do action potentials travel between cardiac cells
Through conduction cells very rapidly
Also connected conduction -> contractile
Also connected contractile -> contractile
What is the excitation and relaxation due to polarisationa nd depolarisation of the heart
Quiesce = Flat line ECG = No electricle impulse (EI)
SA node excites cells = P wave
Full atrial depolarisation = flatline between P and QRS
Start of ventricular depolarisaton + atrial repolarisation = QRS complex = short
Full ventricular depolarisation = between QRS and T
Ventriuclar repolarisation = T
full ventricular repolarisaion = flatline
Quiesce = flatline
What is the function of all cells communicating together
Conduction moves fast throughout the heart
millions of cells act together to create a syncytium
What is the conduction pathway of the heart
SA node located right atrium = pace maker = fires 3 ways
- interatrial bundle -> left atrium = contraction of atria together
- into the right atrium = contraction with left atria
- internodal pathway = down to the AV node
AV node = pasue = waits for the atria to contract
- sends AP down the AV bundle
- Splits to the R and L bundles
- Purkinje fibers
Purkinje fibers = starting at the base of ventricles -> cause Ap to move upwards
- effects septum
- effects lateral wall
- both ventricles contract together
What are the different heart properties graphed to show relivance to one annother
Heart sounds,
electricle impulse
atrial pressure
ventriular pressure
aortic pressure
ventriular volume
When are the two heart sounds heard on an ECG trace
Lubb = Av valves closing
Dubb = SL values closing
