Which muscle cells release Ca2+ from the sarcoplasmic reticulum?

• Myocardial cells

• Skeletal muscle cells

• Smooth muscle cells

• Cardiac muscle cells

What is the role of the ATPase pump in muscle cells?

• To release calcium ions

• To transport calcium ions back into the sarcoplasmic reticulum

• To synthesize ATP

• To open calcium channels

What is the main function of cardiac muscles?

• Pump blood

• Produce movement

• Digest food

• Filter waste

What is the function of the left ventricle?

• To pump blood into the lungs

• To receive deoxygenated blood from the body

• To pump oxygenated blood to the body

• To receive oxygenated blood from the lungs

Which part of the heart is responsible for receiving oxygenated blood from the lungs?

• Right atrium

• Left atrium

• Right ventricle

• Left ventricle

What is the primary function of the sinoatrial (SA) node?

• To pump blood

• To initiate electrical signals

• To regulate blood pressure

• To control heart valves

What is the role of the atrioventricular (AV) node in the cardiac conduction system?

• To initiate the heartbeat

• To delay the electrical signal

• To pump blood

• To regulate blood pressure

Where are the pacemaker cells of the SA node located?

• In the left ventricle

• In the upper posterior wall of the right atrium

• In the center of the heart

• In the left atrium

Why does the AV node delay the contraction signal?

• To allow the ventricles to contract first

• To allow the right atrium and left atrium to contract before the right ventricle and left ventricle

• To stop the heart from beating

• To allow the left ventricle to contract first

What happens after the AV node delays the signal?

• The signal is stopped

• The signal is relayed to the AV bundle

• The signal is sent back to the SA node

• The signal is sent to the left atrium