chapter 18 KAAP
As blood leaves the right ventricle, it passes through the ________ and then into the pulmonary trunk.
pulmonary valve
Coronary veins empty into the
right atrium
Activation of which kind of receptor causes heart rate to increase?
beta-one receptor
What effect would an increase in venous return have on the stroke volume? (Module 18.15B)
An increase in venous return would fill the ventricles with more blood, increasing sarcomere length, which would increase the stroke volume
Define mediastinum
The mediastinum is the region between the two pleural cavities that contains the heart, along with the great vessels, thymus, esophagus, and trachea.
The visceral pericardium is the same as the
epicardium
Pacemaker cells in the SA node
generate action potentials that spread to the myocardium.
Cardiac output is increased by
increased end-diastolic volume, increased stroke volume, more sympathetic stimulation
The circumflex branch and the anterior interventricular artery are branches of the
left coronary artery
Most of the mass of the heart lies to the ________ the midline.
left of
The ________ has a greater workload than the ________.
left ventricle; right ventricle
The coronary sulcus is a groove that
marks the border between the atria and ventricles.
Acetylcholine slows the heart because it
opens potassium ion channels in SA node cells and causes the pacemaker potential to depolarize more slowly.
Which of the following would be greater?
the end-diastolic volume when the heart rate is 60 beats/minute
Which of the following is greater during left ventricular systole?
the peak pressure in the ventricle
The relaxation phase of the lower chambers of the heart is called
ventricular diastole
The T wave on an ECG tracing represents
ventricular repolarization
The long plateau phase of the cardiac muscle action potential is due to
voltage-gated calcium channels remaining open.