Properties Of Cardiac Muscle- Physiology Flashcards
What is compensatory pause?
This is the period after an extrasystole and it occurs due to premature contraction of the heart causing the heart to skip a beat.
What does it mean for the heart to skip a beat after an extrasystole?
This means that due to the firing of an impulse during diastole, this causes the heart to have an extrasystole before the end of diastole, causing the heart to contract again after which it temporarily stops before it starts another cardiac cycle.
How long does the heart stop when an extrasystole occurs?
It stops for 2 Cardiac cycles.
What is the refractory period in muscle physiology?
This is the period during which a muscle will not contract even if an impulse is fired unless it is a greater than normal hence maximum stimulus.
What are the types of refractory period?
1) Absolute refractory period
2) Relative refractory period
What is absolute refractory period?
This is the period during which another muscle contraction will not occur regardless of the intensity of the stimulus fired.
Which part of the heart has the slowest conductivity?
AV Node
Which part of the heart has the fastest conductivity?
Purkinje fibres
The cells making up the Pacemaker are called?
P cells
Why are they called P cells?
Because they are a specialized group of cells having a higher number of gap junctions hence a higher excitability
What is beneficial effect?
This is when the potential or intensity of a contraction is greater than the previous successive contraction due to increased temperature and decreased viscosity of a muscle fiber as a result of previous successive stimuli.
What are the actions of the heart?
1) Chronotropic action
2) Inotropic action
3) Dromotropic action
4) Bathmotropic action
What is Chronotropic action?
This is the frequency of heart beats
The force of contraction of the heart is what heart action?
Inotropic action
What is Dromotropic action?
This involves the conduction of impulse in the heart
