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.