Into which chamber of the heart do the superior vena cava, inferior vena cava, and coronary sinus return deoxygenated blood?
The left side of the heart pumps blood to the body and is therefore considered the systemic circuit pump.
The right side of the heart pumps oxygen-poor blood to the lungs to be re-oxygenated. For this reason, the right side of the heart is considered the pulmonary circuit pump.
Cardiac tamponade results in ineffective pumping of blood by the heart because the excessive amount of fluid in the pericardial cavity will______.
prevent the heart from filling properly with blood
What causes heart sounds?
heart valve closure
The myocardium receives its blood supply from the coronary arteries.
What structures connect the individual heart muscle cells?
Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.
The majority of ventricular filling is caused by contraction of the atria.
Most blood flows passively into the ventricles through open AV valves.
Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.
Pressure in the atria would be greater than the pressure in the ventricles.
What causes the aortic semilunar valve to close?
greater pressure in the aorta than in the left ventricle
Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.
isovolumetric contraction, ventricular ejection, isovolumetric relaxation
Increased pressure in the ventricles would close what valve(s)?
AV valves only
In what direction does blood flow through the heart?
Blood moves through the heart from atria to ventricles and out large arteries, always from areas of high pressure to areas of lower pressure through one-way valves.
Atrial pressure is greater than ventricular pressure during which phase of the cardiac cycle?
At what point during the cardiac cycle does the AV valve close?
when ventricular pressure becomes greater than atrial pressure
At what point in the cardiac cycle does the semilunar valve open?
when ventricular pressure becomes greater than aortic pressure
Ventricular pressure is greater than aortic pressure during which phase of the cardiac cycle?
At what point in the cardiac cycle does the semilunar valve close?
when pressure in the ventricle becomes less than aortic pressure
Isovolumetric relaxation is characterized by which of the following?
The semilunar and AV valves are closed.
At what point in the cardiac cycle does the AV valve open?
when atrial pressure becomes greater than ventricular pressure
Which portion of the electrocardiogram represents the depolarization wave received by the atria from the sinoatrial (SA) node?
What is the period during the cardiac cycle when the ventricles are completely closed and blood volume in them remains constant as the ventricles contract?
isovolumetric contraction phase
Which of the following increases stroke volume?
exercise increases venous return, which would in turn increase the amount of blood in the presystolic ventricle (preload).
Which of these is a condition marked by premature ventricular contraction?
The P wave on an electrocardiogram represents __________.
What best describes afterload?
back pressure exerted by arterial blood
The second heart sound is heard during which phase of the cardiac cycle?
As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve.
the superior vena cava
carries oxygen-poor venous blood from above the diaphragm from areas of the upper body and extremities into the right atrium.
the coronary sinus
carries oxygen-poor venous blood of the coronary circulation into the right atrium.
the inferior vena cava
carries oxygen-poor venous blood from below the diaphragm from the areas of the lower body and extremities into the right atrium.
Assume that blood is flowing from the coronary sinus to the lung capillaries. Place the anatomical labels in order of flow
right atrium -> tricuspid valve -> right ventricle -> pulmonary semilunar valve ->pulmonary trunk -> pulmonary arteries
from left to right, in order of blood flow of oxygen-rich blood into the heart.
Lung capillaries-> Pulmonary veins-> Left atrium-> Mitral/bicuspid valve-> Left ventricle-> Aortic/semilunar valve
mitral (bicuspid) valve
The structure that prevents backflow of blood into the left atrium
The vessel that carries oxygen-rich blood to tissues
The capillaries receiving blood flow from the left side of the heart
aortic semilunar valve
The structure that is located anatomically between the aorta and the left ventricle
Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat.
SA node-> Internodal pathways-> AV node-> AV bundle->Bundle branches-> Purkinje fibers
Electrical link(s) between atria and ventricles
Convey(s) the impulse throughout the ventricular walls
Link(s) between the SA node and AV node
Delay(s) occurs here while atria contract
Convey(s) the impulse down the interventricular septum
Set(s) the pace for the entire heart
Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?
Which of these structures conduct(s) action potentials the slowest?
At what point in the cardiac cycle is pressure in the ventricles the highest (around 120 mm Hg in the left ventricle)?
During which of these stages are the pulmonary and aortic valves open?
Which best describe the isovolumetric contraction phase of the cardiac cycle?
As ventricular systole start, the AV valves are closed and the semilunar valves are closed. Because the ventricles are contracting and both valves are closed, pressure increases rapidly leading to ejection.
As your muscles contract during activity, more blood is returned to the heart. Which variable would be affected and what would be the outcome of this action?
Preload would be increased, which would increase cardiac output.
Which chamber of the heart has the highest probability of being the site of a myocardial infarction?
The atrioventricular (AV) valves prevent backflow of blood into the atria during ventricular contraction.
Name the ridged bundles of muscle found projecting inside the right atrium.
Identify the right atrioventricular valve
Identfiy the valve located at the exit of the right ventricle.
pulmnary semilunar valve
The moderator band is found on both the right and left side of the heart.
Oxygenated blood flows through the right side of the heart.
Identify the most muscular chamber.
Name the inner lining of the heart.
Identify the valve found between the left atrium and left ventricle.
Bicuspid (mitral) valve
What heart chamber pushes blood through the aortic semilunar valve?
Name the needle like ridges of muscle lining the ventricles.
What fibrous structure functions to anchor the atrioventricular valves in a closed position?
Blood on the right never mixes with blood on the left, once the heart is fully developed.
What is the function of the coronary circulation?
Provide a blood supply to the heart
What is the ligamentum arteriosum?
A remnant of the ductus arteriosus
Which chamber of the heart exits into the pulmonary trunk?
Identify the ear like flaps that are attached to the top chambers of the heart.
The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human.
The base of the heart is located at the bottom of the heart.
The left side of the heart pumps the same volume of blood as the right.
If the aorta and pulmonary trunk were switched, oxygen rich blood would be pumped from the left ventricle to the lungs.