what is the function of the fluid that fills the pericardial sac?
To reduce friction during heart activity.
What is the role of the chordae tendineae?
They anchor the AV valve flaps during ventricular systole, thus preventing backflow of blood into the atria.
Differentiate clearly between the roles of the pulmonary and systemic circulations.
The pulmonary circuit provides for gas
exchange only; the systemic circuit provides the functional supply of the body tissues.
Right atrium through the tricuspid valve to the , through the
valve to the pulmonary trunk, to the , to the capillary
beds of the lungs, to the , to the of the heart, through
the valve to the , through the
valve to the , to the systemic arteries, to the of the
tissues, to the systemic veins, to the , , and
entering the right atrium of the heart.
right ventricle; pulmonary semilunar; right and left pulmonary arteries; pulmonary veins; left atrium; mitral/bicuspid; left ventricle; aortic semilunar; aorta; capillary valves; inferior vena cava; superior vena cava; coronary sinus.
Why might a thrombus (blood clot) in the anterior descending branch of the left coronary artery cause sudden death?
This artery supplies blood to the interventricular septum and the anterior walls of both ventricles. Ventricular damage, particularly to
the left ventricle, is very serious.
How would you distinguish the structure of cardiac muscle from that of skeletal muscle?
Skeletal muscle cells are long cylindrical cells with many peripherally located nuclei per cell. Cardiac cells have
one (or two) centrally located nuclei per cell; their branched ends fit together at tight junctions called intercalated discs, which are not seen in