The first two branches of the aorta that supply blood to the tissues of the heart.
Right and Left Coronary Arteries
A branch of the right coronary artery that travels along the posterior interventricular sulcus and supplies the walls of both ventricles.
Posterior Interventricular Artery
A branch of the right coronary artery that passes along the lower border of the heart and supplies the walls of the right atrium and right ventricle.
A branch of the left coronary artery that follows the atrioventricular sulcus between the left atrium and left ventricle, and supplies walls of the left atrium and left ventricle.
A branch of the left coronary artery that lies in the anterior interventricular sulcus, and supplies the walls of both ventricles.
Anterior Interventricular Artery (or Left Anterior Descending Artery)
These drain blood that has passed through the capillaries of the myocardium, they join the coronary sinus which empties into the right atrium.
An enlarged vein on the posterior surface of the heart in the atrioventricular sulcus, it is joined by the cardiac veins and empties into the right atrium.
List the coronary arteries that supply blood to the heart tissues. (2 branches of the aorta, each with 2 branches; 6 in total)
Right Coronary > Posterior Interventricular and Marginal, Left Coronary > Circumflex and Anterior Interventricular
Describe which areas of the heart are supplied by the RIGHT coronary artery.
Its posterior interventricular artery supplies the walls of both ventricles; its marginal artery supplies the walls of the right atrium and right ventricle
Describe which areas of the heart are supplied by the LEFT coronary artery.
Its anterior interventricular artery supplies the walls of both ventricles; its circumflex artery supplies the walls of the left atrium and left ventricle
The volume of the ventricle stays the same, but contracts through the use of force.
Ventricular Isovolumetric Contraction
The initial 70% of blood being forced out of the ventricle at a fast rate.
Ventricular Rapid Ejection
The remaining 30% of blood being forced out of the ventricle at a slower rate.
Ventricular Reduced Ejection
The volume of the ventricle stays the same, but relaxes after contracting.
Ventricular Isovolumetric Relaxation
The initial 70% of blood filling the atria at a fast rate after ventricular contraction.
Ventricular Rapid Filling
The remaining 30% of blood filling the atria at a slower rate after ventricular contraction.
Ventricular Reduced Filling
This heart action means to contract.
This heart action means to relax.
The series of events that constitutes a complete heartbeat.
What does the "Lubb" sound in the first part of a heart beat come from?
During ventricular systole, when the AV valves are closing
What does the "Dupp" sound in the second part of the heart beat come from?
During ventricular diastole, when the pulmonary and aortic valves are closing
List each chamber, valve, and vessel a blood cell would travel trough from the superior vena cava to the aorta. (14 of them)
SVC > RA > TV > RV > PV > PT > PA > AC (lungs) > PV > LA > MV > LV > AV > A
A mass of merging cells that act as a unit of cardiac muscle.
A mass of cardiac muscle fibers acting as a unit in the atrial wall.
A mass of cardiac muscle fibers acting as a unit in the ventricular wall.
Coordinates the events of the cardiac cycle with a series of cardiac impulses throughout the myocardium.
Cardiac Conduction System
Small, elongated mass of cardiac muscle tissue just beneath the epicardium; it reaches threshold and triggers and action potential spontaneously, beginning the cardiac cycle.
Sinoatrial (SA) Node
Since SA node activity is rhythmic, it is also called the _____ because it initiates the heart's rhythmic contractions.
A mass of cardiac muscle tissue in the inferior part of the intertribal septum an just beneath the endocardium; it provides the conduction pathway between the atrial and ventricular syncytia, and delays impulse (relay delay).
Atrioventricular (AV) Node
A group of large fibers that enters the upper part of the interventricular septum and divides into right and left bundle branches that lie just beneath the endocardium, and give rise to purkinje fibers.
AV Bundle (Bundle of His)
These rise from the AV bundle and carry an impulse to distant regions of the ventricular myocardium quickly, so the massive ventricular myocardium can contract as a functioning unit.
List the components of the cardiac conduction system in order. (8 of them)
SA Node > Atrial Syncytium > Junctional Fibers > AV Node > AV Bundle > Bundle Branches > Purkinje Fibers > Ventricular Syncytium
List the 2 functions of the AV Node.
1) Relay impulse between atrial and ventricular syncytia 2) Delay impulse
What is the pacemaker of the heart?
SA Node, because it generates the heart's rhythmic contractions
A recording of the electrical changes in the myocardium during a cardiac cycle.
An abnormally slow heart rate.
An abnormally fast heart rate
In an EKG, what produces a P-wave?
Depolarization of the atria
In an EKG, what is the result of a P-wave?
Contraction of the atria
In an EKG, what produces a QRS-wave?
Depolarization of ventricles
In an EKG, what is the result of a QRS-wave?
Contraction of ventricles
In an EKG, what produces a T-wave?
Repolarization of the ventricles
In an EKG, what is the result of a T-wave?
Relaxation of the ventricles
In an EKG, what produces a PQR interval?
Relay Delay (Caused by the AV Node)
In an EKG, the result of depolarization is _____.
In an EKG, the result of repolarization is _____.
This is the parasympathetic nerve of the heart that secretes Acetyl onto the SA and AV Nodes.
These are the sympathetic nerves to the heart what secrete norepinephrine onto the SA and AV nodes.
What controls the balance between the inhibitory actions of the PNS and the stimulatory actions of the SNS?
Cardiac Control Center
These arise from and signal the cardiac control center in the medulla oblongata when a change in blood pressure is detected.
When baroreceptors in the aorta detect an increase in pressure, they signal the ______ of the medulla oblongata to send parasympathetic impulses to the heart to decrease heart rate.
Cardio Inhibitory Reflex Center
When baroreceptors in the aorta detect a decrease in pressure, they signal the ______ of the medulla oblongata to send sympathetic impulses to the heart to increase heart rate.
Cardio Accelerator Reflex Center
What is the effect of the PNS on cardiac output?
Inhibitory; Acetyl is secreted to decrease SA and AV nodal activity; heart rate is decreased
What is the effect of the SNS on cardiac output?
Stimulatory; norepinephrine is secreted to increase SA and AV nodal activity; heart rate is increased