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nodal/ conducting cells
nodal/conducting cells are special cells that are able to
where is the SA node located
What is the first area to spontaneously depolarize, producing an action potential
pacemaker of the heart
The action potentials travel through the_______
to the _____ ______
from the atrial-ventricular node (AV node) it travels to the bundle ___ ______
From the Bundle of His, the action potential travels through the __________ ______
from the Purkinje Fibers the action potential finally reaches the __________ _________ and leads to contraction
Chronotropic effects
A negative chronotropic effect
A positive chronotropic effect
Dromotropic effects
A negative dromotropic effect decreases conduction velocity through the
A positive dromotropic effect increases conduction velocity through the
A negative inotropic decreases
At rest, a normal heart beats around 50 to 99 times a minute. T or F
Arrhythmias
sinus tachycardia
Sinus bradycardia
Supraventricular arrhythmia
In atrial ES the_ ______ is deformed but the QRS complex is normal.
In nodal extrasystole, stimulation of the atria is retrograde;the P wave is thus negative and is either masked by the QRS wave or appears shortly after it T or F
in supraventricular extrasystole the sinus nodes often also depolarized or repolarized
Automaticity
Increased automaticity could be due to
Reentry circuit
slow-conducting tissue could be due to
Ventricular premature complexes (VPCs
VPCs are the most common ventricular arrhythmia In this case the QRS complex of the extrasystole is deformed T or F
Premature ventricular contraction possible causes
ischemia
Myocarditis
hypertrophic Cardiomyopathy
Hypoxia
Hypercapnia
Mitral valve prolapse
Premature ventricular contraction
symptoms
Frequent episodes of continuous PVCs (Premature ventricular contractions) becomes a form of
ventricular tachycardia
Treatment of Ventricular extrasystole (premature Ventricular Contraction (PVC)
What are the Pharmacological Treatment of Ventricular extrasystole
Class 1 Agents
lidocaine
Class 2 Agents
how do Beta blockers worker
Class II agents include
Class 3 Agents
an example of a class 3 agent is
Class IV agents
Calcium channel blockers.
This class of pharmacological agents allow the body to retain adrenergic control of heart rate and contractility.
Class IV agents include
Atrial tachycardia
Ventricular Tachycardia
What is the bpm range for ventricular tachycardia
in ventricular tachycardia the Ventricular filling and cardiac output
PR interval in the normal heart,
damage to AV node causes slowing of impulse conduction and is reflected by changes in the PR interval. This is considered a
First degree AV node block
Second degree AV node block
Third-degree, or complete, AV node block
What are the are two principal types of myocardial cells
conducting cells
contractile cells
The contractile cells of the heart contain
Contractile Cells differ from skeletal muscle by
Contractile Cells are extremely efficient
at extracting
contractile cells are joined by
intercalated discs contain
gap junctions allow myocardial cells of the heart
Contractility
inotropism is estimated by
Positive inotropic agents produce an
Negative inotropic agents produce
Factors that increase contractility (positive inotropism
what happens when the heart rate increases
Sympathetic stimulation Increases the inward
Factors that decrease contractility (negative inotropism)
Heart murmurs
physiological Murmurs
pathological Murmurs
Abnormal murmurs can be caused by
Stenosis
Valve insufficiency
Causes and symptoms of atrial flutter
Atrial fibrillation and flutter
atrial flutter
atrial fibrillation
When the atria fibrillates what happens with the blood
Atrial fibrillation may also result from an
atherosclerosis
what is the plaque buildup in atherosclerosis made up of
Which arteries are affected by atherosclerosis
what are the causes of atherosclerosis
symptoms of atherosclerosis
complications of atherosclerosis
The hallmark of atherosclerosis is
atherosclerotic plaque contains
All stages of atherosclerosis—from initiation and growth to complication of the plaque—are considered an
Endothelial dysfunction
how are the plaques built in atherosclerosis
Preload
When venous return increases, end-diastolic volume_________ and stretches or lengthens the ventricular muscle fibers
Afterload
For the left ventricle: Increases in aortic pressure cause an increase in afterload on the____ ventricle.
Afterload for the right ventricle is equivalent to
Increases in pulmonary artery pressure cause an increase in afterload on the ______ ventricle
Saromere length
Sarcomere length determines the maximum t
Velocity of contraction is maximal when the afterload is
Velocity of contraction is decreased by increases
Frank-Starling relationship
Frank-Starling relationship is based on the
the mechanism that matches cardiac output to venous return.
The greater the venous return, the greater the cardiac output.
Increases in contractility cause an increase in
Decreases in contractility cause a
Isovolumetric ventricular contraction is also known as
Isovolumetric ventricular contraction begins with
How are the ventricles filled during isovolumetric ventricular contraction
The mitral valve closes when left ventricular pressure is
What makes Step 1-2 Isovolumetric
Step 2-3 Ventricular Systole
When does the aortic valve open during the cardiac cycle
Step 2-3 Blood is ejected into _____ and ventricular volume decreases
. The volume that is ejected in ventricular systole is
The volume remaining in the left ventricle at point 3 is
Step (3-4) is known as
At what point does the ventricle relax
When ventricular pressure decreases to less than aortic pressure, the_____ valve closes.
Late ventricular diastole is known as
left ventricular pressure decreases to less than left atrial pressure, the valve opens and filling of the ventricle begins
During what phase, ventricular volume increases to about 140 ml (the end-diastolic volume).
Increased preload
refers to
Increased preload causes an increase in________ ________ base on the Frank-Starling relationship
The increase in stroke volume is reflected in increased
Increased afterload
refers to an increase in
in Increased after load The ventricle must eject blood against a higher pressure, resulting in a
The decrease in stroke volume is reflected in _______ _______ of the pressure-volume loop
The decrease in stroke volume results in an _________ in end-systolic volume.
. Increased contractility
The increase in SV results in a_____in end-systolic volume.
Stroke volume
How do you find the stroke volume
How do you find the cardiac output
Ejection fraction is normally what percentage
ejection fraction
Cardiac Oxygen consumption is directly related
Cardiac oxygen consumption is increase by
In order for blood to be ejected from the heart, the pressure in the ventricles must be
When the pressure in the left ventricle rises above 80 mmHg
What is the pressure in the aorta
When the aortic valve open and receives blood the pressure increases to
ejection period
The first heart sound is produced by the closure of the
The second heart sound is produced by the closing of
third heart sound sometimes occurs in the middle of diastole T or F
What is the third heart sound caused by
What is cardiac output
At rest the cardiac output is
during vigorous exercise it can increase up to
stroke volume (SV) is the amount of blood pumped by
resting heart rate is
Which nervous system controls the heart rate and the force of contraction
the heart is innervated by
parasympathetic nerves are distributed mainly to
Sympathetic nerves are distributed
parasympathetic nervous system will decrease heart rate by
sympathetic nervous system ________ heart rate and force of contraction.
