1 Electrical Activity Of The Heart Flashcards
Which side of the heart is involved in pulmonary circulation?
How many chambers?
RIGHT
Left is SYSTEMIC
4 2 atria and 2 ventricles
What are the names of the two atrioventricular valves and which side are they on?
What about the 2 semilunar valves?
Bicuspid (mitral)- LEFT
Tricuspid- RIGHT
Aortic valve-LEFT
Pulmonary valve- RIGHT
What’s a period of contraction, force generation, and blood expulsion?
What’s a period of relaxation, filling with blood, readying for next systole?
Systole
Diastole
(TP) Left atrial fibrillation (improper excitation and contraction) would most greatly affect filling of which other heart chamber?
A. Left ventricle
B. Right ventricle
C. Right atrial
D. Left atria
Left ventricle
The ___ node is the pacemaker of the heart because it’s the fastest. Fires while others are still slowly depolarizing
SA
The _______ pacemaker can override SA node if:
__ node slows
_______ is faster
Pathology introduces a conduction block
Ectopic
SA
Ectopic
List the steps of flow for depolarization
SA node fires
Atria depolarize (right first from base to apex)
Septum and inner ventricular muscle
Ventricles (all at once)
Coordination allows for maximal blood ejection
Heart rate is modulated by altering the __ node firing rate. Altering conduction through the __ node as well.
SA
AV
Sympathetic control of the SA node is positive _______ stimulation that ______ HR.
Has _1 receptors. Increases funny current and Ca current
Chronotrope. INCREASE
B1
Parasympathetic autonomic control of SA node is a _______ chronotrope which _______ HR.
_2 receptors.
______ Ca current and funny current
______ K current
Negative. Decreases
M2
Decreases
Increases
The sympathetic autonomic control of the AV node is a _______ dromotrope that _______ conduction velocity.
B1 receptors
______ Ca current during upstroke
______ ERP
Positive. Increases
Increases
Shortens
Parasympathetic control of AV node is a ________ dromotrope that _______ conduction velocity.
M2 receptors
_______ Ca current during upstroke
______ K current to hyperpolarize
_______ ERP
Negative. Reduces
Decreases
Increases
Lengthens
What is the time from initiation of atrial depolarization to initiation of ventricular depolarization? Usually between .12-.2 seconds
PR interval
What’s the time from first ventricular depolarization to last?
QT interval
What’s the time from last depolarization to initiation of repolarization?
ST segment
