<3 Flashcards
What are the 3 layers of the heart?
myocardium, endocardium, epicardium
What are the two layers of the pericardium?
inner (visceral) and outer (parietal)
Where does the heart lie?
within the thorax in the mediastinal space
What divides the heart?
septum
Is the atrial myocardium thicker or thinner than ventricular myocardium?
thinner
Why are the ventricular walls thick?
To make the force needed to pump blood into systemic circulation
Trace the blood flow through the heart
The right atrium receives venous blood from the inferior and superior venae cava and the coronary sinus. The blood then passes through the tricuspid valve into the right ventricle. With each contraction, the right ventricle pumps blood through the pulmonic valve into the pulmonary artery and to the lungs. Oxygenated blood flows from the lungs to the left atrium by way of the pulmonary veins. It then passes through the mitral valve and into the left ventricle. As the heart contracts, blood is ejected through the aortic valve into the aorta and thus enters the systemic circulation.
How many valves are in the heart?
4
Why are the heart valves important?
They keep blood flowing forward
How are the mitral and tricuspid valves anchored?
chordae tendinae anchor themselves to the valves and to the papillary muscles of the ventricles
Which valves will prevent eversion of the leaflets into the atria during ventricular contraction?
tricuspid and mitral valves
Which valves will prevent blood from regurgitating into the ventricles at the end of each ventricular contraction?
semilunar valves (pulmonic and aortic valves)
What supplies blood to the myocardium?
coronary circulation
When will blood flow into the 2 major coronary arteries?
during diastole
Where does the left coronary artery arise from?
aorta
What are the two branches of the left coronary artery?
left anterior descending and left circumflex artery
What do the left coronary arteries supply blood to?
left atrium, left ventricle, interventricular septum, and part of the right ventricle
Where does the right coronary artery arise from?
aorta
What does the right coronary artery supply blood to?
right atrium, right ventricle, and part of the posterior wall of the left ventricle
What will supply blood to the AV node and bundle of His in 90% of people?
right coronary artery