Cardiovascular system crash course pt. 2

What is a common misconception about the use of defibrillators in emergency situations as portrayed in media?

• They can cure any heart disease

• They are only used in cases of minor injuries

• They stop the heart to reset its rhythm

• They are used to restart the heart

What is a key difference between skeletal and cardiac muscle cells?

• Cardiac muscle cells are interconnected both physically and electrically

• Skeletal muscle cells can generate their own electricity

• Cardiac muscle cells have multiple nuclei

• Skeletal muscle cells are branched

What percentage of a cardiac cell is made up of mitochondria?

• 10 to 15 percent

• 25 to 35 percent

• 5 to 10 percent

• 40 to 50 percent

What unique ability do pacemaker cells have?

• They can contract without electrical impulses

• They are not affected by the body's nervous system

• They generate their own action potentials without external stimuli

• They can survive without oxygen

What is the main function of the SA node in the heart?

• To pump blood throughout the body

• To delay the electrical signal

• To act as the heart's natural pacemaker

• To contract the ventricles

What is the purpose of the delay in the AV node during the heart's electrical impulse travel?

• To give time for the atria to finish contracting

• To slow down the heart rate

• To allow the ventricles to contract first

• To prevent the signal from reaching the ventricles

What is the role of Purkinje fibers in the heart?

• To ensure ventricles contract efficiently from the bottom up

• To connect the heart's chambers

• To delay the electrical signal

• To generate the heart's initial electrical impulse

How do defibrillators actually work to save lives during cardiac arrest?

• By restarting the heart immediately

• By providing continuous electrical stimulation

• By stopping the heart to reset its rhythm

• By increasing the heart's oxygen supply

Tags

NGSS.HS-PS2-5

Why can't CPR correct fibrillation on its own?

• It is only a temporary measure until professional help arrives

• It only works on conscious patients

• It stops the heart from beating

• It cannot generate electrical impulses

What is the main reason defibrillators are used during cardiac arrest?

• To increase blood flow to the heart

• To provide a steady rhythm to the heart

• To immediately restart the heart

• To reset the heart's rhythm by stopping it momentarily