Correct. The coronary circulation provides oxygenated blood to the heart through coronary arteries. Coronary veins return the deoxygenated from the heart to the coronary sinus on the posterior surface of the heart. The coronary sinus empties the deoxygenated blood directly into the right atrium where it joins deoxygenated from the body.
The ligamentum arteriosum is a remnant of the ductus arteriosus. The ductus arteriosus is a fetal shunt that connects the pulmonary trunk to the aorta.
The right ventricle pumps deoxygenated blood through the pulmonary semilunar valve into the pulmonary trunk to be distributed to the lungs.
The auricles are flap like extensions of the atria that are observed on the external surface of the heart
In both the sheep and human, the brachiocephalic artery is the first major vessel to exit the arch of the aorta. Further branching of the brachiocephalic artery and the arch of the aorta differs between a sheep and a human.
The base is located at the top of the heart. It is unusual to see the largest portion of an organ at the top. Typically, the base is at the bottom of an organ, as in the lungs.
The left ventricle is responsible for pumping blood out to the body. This requires a lot of force. The left ventricle is the most muscular in order to pump the blood with adequate force
The endocardium is the smooth, slick lining of the chambers of the heart. Endocardium is a continuation of endothelium that lines blood vessels. Both endocardium and endothelium are composed of simple squamous epithelial tissue, which minimizes friction between the wall of the chamber/vessel and the blood.
The atrioventricular valve on the left is the bicuspid valve. The mitral valve is also called the mitral valve.
The aortic valve is located between the left ventricle and the aorta. The left ventricle pumps oxygenated blood out of the heart through the aortic valve to the body.
Correct. Trabeculae carneae are the small elevated ridges of muscle arranged in a web type fashion found in both the right and left ventricles.
Correct. Chordae tendineae are the fibrous cords that attach the atrioventricular valves to papillary muscles. They help anchor the atrioventricular valves in a closed position during ventricular contraction.
Correct. Once fetal modifications (i.e. foramen ovale, ductus arteriosus) close following delivery of the infant, blood on the right side of the heart should not mix with blood on the left side of the heart.
Correct. The pectinate muscles are ridge like elevations of muscle. They are parallel to each other and resemble teeth of a comb. They are easily observed inside the right atrium.
Correct. The tricuspid valve is the atrioventricular valve located on the right side of the heart. It separates the right atrium from the right ventricle.
Correct. The pulmonary valve is the semilunar valve found between the right ventricle and the pulmonary trunk. Deoxygenated blood travels through the pulmonary valve as it exits the right side of the heart on its way to the lungs.
Correct. The moderator band is a cord like structure found in the right ventricle. It contains portions of the cardiac conduction system that help convey the electrical message for the ventricles to contract. It works as a shortcut within the cardiac conduction system.
Correct. Oxygenated blood returning from the lungs is received by the left atrium, then to the left ventricle before being pumped out to the body. This pathway of blood flow is known as the systemic circulation.
Yes, action potentials generated by the autorhythmic cells spread waves of depolarization to contractile cells through gap junctions. If the depolarization causes the contractile cells to reach threshold, they will in turn generate an action potential.
Yes, if there is a decreased efflux of potassium while there is a normal influx of sodium, the inside of the cell would become less negative. Thus, threshold would be reached. The ability of these autorhythmic cells to spontaneously depolarize is what results in the pacemaker potential.
Yes, unlike nerve cells or cardiac muscle cells, fast calcium channels are responsible for the depolarization phase of the autorhythmic cell action potential. When the fast calcium channels open, calcium rushes into the cell making it less negative (or more positive).
Yes, opening of voltage-gated potassium channels causes positive potassium ions to move out of the cell. This efflux of potassium causes the cell to become more negative inside thus, repolarizing the cell.
Yes, the flow of positive ions from the autorhythmic cells (or adjacent cells) brings the membrane to threshold initiating depolarization of the contractile cell.
Yes, the SA Node spontaneously depolarizes, causing the wave of depolarization that spreads through the rest of the conduction system and heart.
Yes, the ECG waves show the depolarization and repolarization in various areas of the heart.
Yes, the QRS complex represents depolarization in the ventricles, which have greater mass than the atria.
Yes, the P wave represents atrial depolarization, which leads to atrial contraction.
Yes, the AV node slows down the impulse giving the atria time to contract before the ventricles contract.
Yes, both occur during ventricular diastole when the ventricles are not actively contracting and ejecting blood.
Yes, most of the ventricular filling is passive; atrial contraction adds just a little more blood.
Yes, higher pressure in the atria than in the ventricles forces the AV valves to open and blood moves into the ventricles.
Yes, backflow of blood in the aorta (towards the left ventricle) closes the aortic semilunar valve.
Yes, the ventricles must contract and eject blood before they relax and fill again.
Yes, increased pressure in the ventricles would close the AV valves.
Sympathetic stimulation leads to the release of epinephrine and norepinephrine, both of which increase heart rate and increase contractility, which increases stroke volume. Increasing heart rate and stroke volume increases cardiac output.
Increasing afterload decreases stroke volume.
The SV is calculated by subtracting the ESV from the EDV. You are comparing the volume of the ventricle at its fullest to its emptiest.
Intercalated discs connect the heart muscle cells. They include desmosomes (anchoring junctions) and gap junctions (communicating junctions).
The myofibrils of cardiac muscle have various diameters; they also branch in order to maintain connections, via intercalated discs, with other muscle cells.
All systemic veins return oxygen-poor venous flow to the right atrium, through the tricuspid to the right ventricle, and up and out the pulmonary semilunar valve to the pulmonary trunk and pulmonary arteries to the capillaries of the lungs.
Returning oxygen-rich blood flowing through pulmonary veins enters the left atrium, passes through the mitral valve to the left ventricle, and flows out through the aortic semilunar valve into the aorta and on to systemic capillaries.
Congratulations on completing blood flow through the two-sided heart, identifying oxygen-rich and oxygen-poor locations, and preparing yourself for knowledge you will use again and again!