Heart

The following is a list of vessels and structures that are associated with the heart. What is the correct order for the flow of blood entering from the systemic circulation? 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins

5, 1, 3, 7, 8, 2, 4, 6

The following are structural components of the conducting system of the heart. 1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches

4,3,2,5,1

The ________ is the amount of blood in a ventricle after it has contracted and before it begins to refill.

End-systolic volume

If the pacemaker cells in the SA node become more permeable to potassium ions, the

Heart rate will decrease and cells will hyperpolarize

In cardiac muscle, the fast depolarization phase of the action potential is the result of

Increased membrane permeability to sodium ions

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.

QRS complex

The long plateau phase of the cardiac muscle action potential is due to

calcium channels remaining open.

A procedure in which a length of the patient's vein or artery is used to create a detour around an obstruction in a coronary artery is called

coronary artery bypass .

During the beginning of ventricular systole when the muscle is contracting but not enough pressure has built up to open the semilunar valves the heart is said to be in

isovolumetric contraction.

Blood returning to the heart from the pulmonary circuit first enters the

left atrium

Blood leaves the right ventricle by passing through the

pulmonary valve

The right atrium receives blood from all of the following structures except the

pulmonary veins

Compared to the right ventricle, the left ventricle has all the following characteristics except

pumps a greater volume

Blood returning to the heart from the systemic circuit first enters the

right atrium

The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the

systolic ejection phase.

As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit

tetany

Blood is supplied to the myocardium by

the coronary arteries.

The normal pacemaker of the heart is located in

the sinoatrial node.

Which of the following is not true regarding the right atrioventricular valve?

The valve closes when the right atrium contracts.

Which of the following statements is true regarding cardiac muscle?

There are specialized gap junctions in cardiac muscle not found in skeletal or smooth muscles.