Physiology Flashcards
(37 cards)
Cardioacceleratory centre
sympathetic neurons.
Cardioinhibitory centre
parasympathetic fibers
electrocardiograph which can detect the electrical currents of the heart
Can be detected with … ?
Leads or electrodes
deflections above and below the baseline.
-Atrial depolarization (SA node) ?
The P wave
deflections above and below the baseline.
Ventricular depolarization & atrial repolarization ?
The QRS complex.
deflections above and below the baseline.
Ventricular repolarization?
The T wave
action potential spreads through the atria and depolarizes them.
P wave
small downward deflection called
called Q,
tall sharp peak, called
R
final downward deflection, called
S
Atria repolarize here, then relax.
The QRS
Ventricular contraction begins shortly
after the QRS complex.
represents ventricular repolarization, immediately prior to ventricular relaxation.
T wave
blood forced from heart chambers
contraction = systole
heart fills with blood
relaxation = diastole
-Produced as a result of the AV valves closing at the start of ventricular contraction
-When blood pushed up underneath valves
first heart sound (S1)
Produced as a result of the semilunar valves closing at the beginning of ventricular relaxation
second sound (S2)
When decrease in pressure allows backflow from large arteries
second sound (S2)
The first heart sound S1 is known as
lubb
lasts a little longer than the second sound S2 known as
dubb
the amount of blood pumped out by each ventricle in 1 minute.
Cardiac output (CO)
It is the product of the heart rate (HR) and the stroke volume (SV)
Cardiac output (CO)
the volume of blood pumped out by a ventricle with each heartbeat.
Stroke volume
increases as the force of ventricular contraction increases
Stroke volume
