The "lub" sound indicates what?
The closing of the VA valves.
The "Dub" sound indicates what?
The closing of the semilunar valves.
The __________ contracts independently of the nervous system?
______________ are gap junctions that connect cardiac muscle cells and allow it to beat and contract as one unit?
Name 5 non-contractile cells within the heart that stimulate a synchronized heart rythum:
SA (Sinoatrial node)
AV (Atrioventricular node)
Know as the "pacemaker of the heart.
SA (Sinoatrial) node
Functions as a relay point that delays the contraction of the ventrical.
AV (atrioventicular) node
Only place within the heart where there is a connection between atria and ventricles.
Extends through the interventricular septum.
Travel through the ventricular wall.
Name 7 controls on heart rate:
Autonomic Nervous System (parasympathetic and sympathetic)
Hormones (epinephrine, thyroid hormone)
Electrolytes (Ca, Na, K)
Records the electrical activity of the heart.
ECG stands for what recording of electrical heart activity?
Ventricular contraction is known as __________?
Ventricular relaxation is known as _________?
Name the three wave of the cardiac cycle:
What event occures during the P wave?
Atrial depolarization (contraction)
What event occures during the QRS complex?
Ventricular depolarization (contraction)
What event occurs during the T wave?