What node is also known as the ‘pacemaker’?

• Bundle of His

• Purkinje fibers

• Atrioventricular node

• Sinoatrial node

What is the term for an abnormally fast heart rate?

• Lackofexercisia

• Bradycardia

• Tachycardia

• Coronaria

On an EKG, the QRS spike indicates what process in the heart?

• Atrias depolarizing

• Ventricles depolarizing

• Hesitation at the AV node

• A murmur

Which of the following can affect cardiac output?

• Hormones

• Stroke volume

• Sympathetic and Parasympathetic nervous system

• All of the above

Tags

NGSS.HS-LS1-3

During rapid depolarization of ventricular cardiac cells, which voltage channels open?

• Potassium

• Calcium

• Troponin

• Sodium

When the ventricles contract, the papillary muscles also contract, which

• tightens the chordae tendineae preventing the AV valves from prolapsing

• tightens the chordae tendineae, causing the AV valves to open

• loosens the chordae tendineae, allowing the semilunar valves to open.

• loosens the chordae tendineae, allowing the semilunar valves to close.

Tags

NGSS.HS-LS1-3

Bradycardia is:

• Irregular heart beat

• Low blood pressure

• Increase in blood viscosity

• Abnormally slow heart rate

Tags

NGSS.HS-LS1-3

During diastole, the ventricular chamber of the heart:

• Relaxes and fills with blood

• Contracts and pushes blood out

• Experiences a sharp increase in pressure

• Reaches a pressure of approximately 120 mmHg

In the action potential of a myocardial cell, the Ca²⁺ gates close:

• at threshold

• just as the cell begins to depolarize

• at the end of the plateau

• at the end of repolarization