It's Electric
What does the sinoatrial (SA) node do?
Acts as the hearts pacemaker (creates electrical signals that allow the heart to beat)
Epicardium
Name a main component of the cardiovascular system
Heart
Blood Vessels
Blood
Name the three types of blood vessels
Arteries, veins, & capillaries
What causes the "lub-dub" sound of a heartbeat?
Opening and closing of heart valves
What does the atrioventricular (AV) node do?
It delays the electrical response
Myocardium
What is the primary function of the pulmonary circuit?
To exchange oxygen and carbon dioxide in the lungs
Which type of blood vessel has the thickest walls?
Arteries
Approximately how many times does the human heart beat in a day?
100
How might the heart's electrical process change during exercise?
The heart rate increases, but the sequence remains the same
What is the innermost layer/lining of the heart?
Which chamber of the heart pumps oxygenated blood to the body?
Left ventricle
Why do capillaries have very thin walls?
To allow for material exchange with tissue
What condition is characterized by a buildup of plaque in the arteries?
Atherosclerosis
Which of the following best explains the importance of the AV node's delay in the heart's electrical system?
It allows time for the ventricles to fill with blood
Why does the left ventricle have a thicker myocardium than the right ventricle?
To pump blood throughout the entire body
What is the main function of heart valves?
To ensure one-way blood flow (Prevent backflow)
Why do arteries and veins have smooth muscle in their walls?
To expand and dilate based on bloodflow and the needs of the body (i.e. Vascular Spasm)
Which phase of the cardiac cycle represents the relaxation of heart chambers?
Diastole
What pathways do the electrical impulses flow through in the heart?
Bundle of His & Purkinje Fibers
Name a unique property of cardiac muscle that distinguishes it from skeletal muscle
Can contract continuously without fatigue
Has more mitochondria than other muscle types
Contracts rhythmically on its own
Works involuntarily - you can't control it consciously
What are the four main valves of the heart?
Tricuspid valve
Pulmonary valve
Mitral valve
Aortic valve
List the correct order of blood flowing through the heart
Right atrium → right ventricle → lungs → left atrium → left ventricle -- body
How does the brain help regulate heart function?
By controlling the heart rate