Cardiac Cycle
What does the term cardiac cycle mean?
A complete heartbeat or pumping cycle of contraction and relaxation of both atria and both ventricles.
How many chambers are in the heart?
Where is the heart located?
In the thoracic cavity, specifically the mediastinum.
What do you call the fibers that initiate signals for the heart to pump?
Pacemaker fibers
What is the heart’s special covering called?
The Pericardium.
What does isovolumetric mean?
It means having the same measured volume.
How many grams does the average male heart weigh?
310 grams
What are the two parts of the pericardium?
The fibrous portion and a serous portion
True or False: the heart needs to pump rhythmically in order to be efficient.
True
What’s the texture of the heart’s covering?
Smooth
True or False: Rapid ejection is characterized by a marked decrease in ventricular and aortic pressure and in aortic blood flow.
False, it is marked by an increase.
Do the atria (top chambers of the heart) receive or pump out blood?
Receive
What are the three main types of blood vessels in the heart?
Artery, Vein, and Capillary
Does the impulse that initiates heart pumping occur in the Sinoatrial node or the Subendocardial branches?
Sinoatrial node
True or False: the heart’s covering wraps tightly around the heart.
False
What happens when the contracting force of the atria creates a pressure gradient?
It pushes blood out of the atria into relaxed ventricles.
True or false: The shape of someone’s heart differs depending on their body type.
True
What does endothelium do?
It lines the heart (endocardium location) and continues on to line ALL of the blood vessels.
True or False: Myocardial contraction and heart beats are the same.
False
Which layer of the heart’s covering is deeper, the Fibrous pericardium or the serous pericardium?
The Serous pericardium
What is the correct order of the cardiac cycle: Ejection, isovolumetric ventricular contraction, passive ventricular filling, isovolumetric ventricular relaxation, atrial systole.
Atrial systole, isovolumetric ventricular contraction, ejection, isovolumetric ventricular relaxation, passive ventricular filling.
How many directions do heart valves allow blood to flow?
1
What is considered the “pumping chambers” of the heart?
Ventricles
What is the average heart rate at rest?
70-75 beats per minute
What is the primary purpose of the fibrous pericardial sac?
To protect the heart from friction by producing lubricating serous fluid.