Cardiovascular System: Heart Anatomy, Function, and Blood Flow

Blood drained from body regions inferior to the diaphragm return to the heart through the ____.

inferior vena cava

Pulmonary veins _____.

transport blood from the lungs to the heart

The vein which drains the capillary beds of the myocardium is the _____.

coronary sinus

The epicardium of the heart is also known as the ____.

visceral pericardium

Cardiac muscle forms which layer of the heart?

myocardium

The myocardium in the walls of the heart is thickest in the

left ventricle

Reducing friction due to blood flow as blood passes through the chambers of the heart is the function of which layer of the heart?

endocardium

The interatrial septum is found separating _______.

the left and right atria

What is the function of the outer, fibrous pericardium?

protecting the heart and anchoring it to surrounding structures

The condition in which cardiac tissue dies and is replaced by scar tissue, resulting in decreased pumping efficiency, is ______.

myocardial infarction

Which substance causes a slow, sustained increase in heart rate when present in large quantities?

thyroxine

List the parts of the intrinsic conduction system of the heart in order from beginning of the impulse to end.

1. Sinoatrial node

2. Atrioventricular node

3. Atrioventricular bundle

4. Right and left bundle branches

5. Purkinje fibers

What is the pacemaker in a normally functioning heart?

sinoatrial node (SA node)

Contraction of the ventricles occurs as the electrical impulse of the intrinsic conduction system moves through which part?

Purkinje fibers

What is the effect of increased blood calcium levels on the heartbeat?

irritability and spasms

Cardiac output equals ______.

the amount of blood pumped out by each ventricle in one minute (CO = heart rate (HR) x stroke volume (SV)

Cardiac output increases

when stroke volume or heart rate increases (directly proportional )

Which of the following is associated with the diastolic blood pressure reading?

ventricular relaxation

The blood flow in the coronary circulation stops and starts in response to ventricular contraction and relaxation.

True