Chapter 18 (Exam 3) Flashcards
Put the following in order of the hearts conducting system. (Purkinje fibers, AV bundle, AV node, SA node, and bundle branches.)
SA Node AV Node AV Bundle Bundle Branches Purkinje Fibers
What keeps Cardiac muscle from reaching tetanus?
Cardiac muscle has a refractory period that lasts until the muscle is relaxed
____ cells make up the middle layer of the heart wall.
Cardiac Muscle Cells
____ activates the sympathetic neurons.
Cardioacceleratory center
____ controls parasympathetic neurons.
Cardioinhibitory Center
The neurons that control heart rate are located where in the cardiovascular center?
Hypothalamus
____ is called the relaxation phase of the cardiac cycle.
Diastole
Exchange between a blood vessel and the cells that surround it can only occur where?
Capillaries
Depolarization of the ventricles is represented on a ECG by the ____.
QRS Complex
Which sound is associated with the closing of the mitral valve?
The first heart sound “lubb”
____ closes when the left ventricular pressure exceed the left atrial pressure.
Mitral Valve
___ of ventricular systole is the phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open.
Ventricular Ejection
____ will not increase cardiac output?
Increased parasympathetic stimulation
____ is a characteristic of the stage of rapid depolarization of cardiac muscle.
Massive influx of sodium ions
Blood exits the right ventricle through the ____.
Pulmonary valve
What is represented by the T wave on an ECG?
Ventricular Repolarization
increased activity by the parasympathetic nervous system is caused by ____.
Aortic baroreceptors
All valves are closed during what phase of ventricular systole?
Isovolumetric Contraction
Blood flow is slowest where?
Capillaries
Depolarization of the atria is represented by what on an ECG?
The P wave on an ECG
Intercalated discs transfer what from cell to cell?
Action Potentials
In what position are the AV valves during Ventricular systole?
Closed
The left ventricle pumps blood to the ____.
Aorta
____ opens potassium ion channes in the SA node cells and causes the pacemaker potential to depolarize more slowly, causing the heart to slow.
Acetylcholine
____ collects blood and pumps it into the ventricles.
Atrium
The long plateau phase of the cardiac muscle action potential is due to what?
Open calcium channels
Where does the right ventricle pump blood to?
Lungs
Blood pressure is highest where?
Arteries
____ is the amount of tension the contracting ventricle must produce to force open the semilunar valve and eject blood.
Afterload
AV valves allow blood to flow in how many directions.
1
Where is the pacemaker located?
SA node
____ prevent the AV valves from reversing into the atria.
Papillary muscle contractions
Isovolumetric contraction is associated with which cardiac cycle
Ventricular Systole
The ____ is the volume of blood ejected from each ventricle during a contraction.
Stroke volume
What is the correct order for the flow of blood entering form the systemic circuit? Right Atrium Left Atrium Right ventricle Left Ventricle Venae Cavae Aorta Pulmonary trunk Pulmonary veins
Venae Cavae Right Atrium Right Ventricle Pulmonary Trunk Pulmonary veins Left atrium Left ventricle Aorta
____ generate action potential that spread tot he myocardium
Pacemaker cells
____ is the difference between the systolic and diastolic pressure.
Pulse
Blood passes through ____ after leaving the right ventricle but, before entering the pulmonary trunk.
Pulmonary Valve
What happens to the AV valves when the semilunar valves close?
AV Valves close
Blood flows through what valve after leaving the venue cavae?
Tricuspid valve
Decreasing the diameter of a blood vessel by half would cause the vascular resistance to (increase/decrease)?
Increase
The ____ is the muscle layer of the heart?
Myocardium
3 reasons that the wall of the left ventricle is thicker than the right?
It produces a higher pressure
It pumps against greater resistance
It does more work that the right
The cusps (leaflets) of AV Valves attach directly to ____?
Chordae tendinae
Blood returning to the heart form the pulmonary circuit first enters the ____.
Left atrium
____ is known as the contraction phase of the cardiac cycle.
Systole
Another name for the visceral pericardium is the ____.
Epicardium
The ____ supply blood to the myocardium.
Coronary arteries
Where is the bicuspid (mitral) valve located?
Between the left atrium and left ventricle
