Human Physiology: Cardiovascular System Quiz

<p>All of the above (D)</p> Signup and view all the answers

<p>QRS complex (A)</p> Signup and view all the answers

<p>The septum (B)</p> Signup and view all the answers

<p>To control the rate of heart contraction (B)</p> Signup and view all the answers

<p>Tricuspid valve (A)</p> Signup and view all the answers

<p>Auricle (B)</p> Signup and view all the answers

<p>Carry oxygenated blood to the body (D)</p> Signup and view all the answers

<p>Diastole (D)</p> Signup and view all the answers

<p>To ensure that the heart chambers fill completely (C)</p> Signup and view all the answers

<p>Sinoatrial (SA) node (D)</p> Signup and view all the answers

<p>Blood vessels (B)</p> Signup and view all the answers

<p>Carry deoxygenated blood to the lungs (D)</p> Signup and view all the answers

<p>Right atrium (C)</p> Signup and view all the answers

<p>Aortic valve (B)</p> Signup and view all the answers

<p>The right heart pumps deoxygenated blood, while the left heart pumps oxygenated blood. (C)</p> Signup and view all the answers

<p>Producing red blood cells (D)</p> Signup and view all the answers

<p>Carry oxygenated blood from the lungs (A)</p> Signup and view all the answers

<p>Sinoatrial (SA) node (D)</p> Signup and view all the answers

<p>Annulus (D)</p> Signup and view all the answers

<p>To collect blood before it is pumped into the ventricles (C)</p> Signup and view all the answers

<p>It can generate its own electrical impulses (D)</p> Signup and view all the answers

<p>To prevent backflow of blood from the ventricles to the atria (A)</p> Signup and view all the answers

<p>To carry deoxygenated blood from the heart to the lungs (D)</p> Signup and view all the answers

<p>Right atrium, right ventricle, left atrium, left ventricle (D)</p> Signup and view all the answers

<p>To prevent backflow of blood from the ventricles to the great arteries (B)</p> Signup and view all the answers

<p>They have a high pressure system. (A)</p> Signup and view all the answers

<p>Automaticity (C)</p> Signup and view all the answers

<p>The period of relaxation of the heart (D)</p> Signup and view all the answers

<p>To contract and pump blood throughout the body (B)</p> Signup and view all the answers

<p>Muscle contractions in the legs (D)</p> Signup and view all the answers

<p>To regulate blood volume (C)</p> Signup and view all the answers

<p>The ventricles contract to pump blood out of the heart (A)</p> Signup and view all the answers

<p>Atrial and Ventricular Syncytia (B)</p> Signup and view all the answers

<p>The arrangement of actin and myosin filaments (A)</p> Signup and view all the answers

<p>Tricuspid Valve (C)</p> Signup and view all the answers

<p>Slowing down the impulse to allow for atrial contraction and ventricular filling (C)</p> Signup and view all the answers

<p>The strength of the heart's contraction is directly proportional to the volume of blood filling the ventricles (A)</p> Signup and view all the answers

<p>They close tightly to prevent blood from flowing back into the atria (C)</p> Signup and view all the answers

<p>Bundle Branches and Purkinje Fibers (C)</p> Signup and view all the answers

<p>Systole (B)</p> Signup and view all the answers

<p>To ensure blood flows in the correct direction (C)</p> Signup and view all the answers

<p>To ensure complete filling of the ventricles (D)</p> Signup and view all the answers

<p>Near the top of the right atrium (A)</p> Signup and view all the answers

<p>Ectopic Pacemaker (D)</p> Signup and view all the answers

<p>Automaticity (C)</p> Signup and view all the answers

<p>The pulmonary circulation carries deoxygenated blood to the lungs, while the systemic circulation carries oxygenated blood to the body (D)</p> Signup and view all the answers

<p>It ensures the heart continues to function in the event of brain damage (A)</p> Signup and view all the answers

<p>AV Node (D)</p> Signup and view all the answers

<p>Systole (C)</p> Signup and view all the answers

<p>Conductivity (C)</p> Signup and view all the answers

<p>AV node (C)</p> Signup and view all the answers

<p>The cell cannot be stimulated, regardless of the strength of the stimulus. (C)</p> Signup and view all the answers

<p>To transport oxygen and nutrients to cells and remove waste products. (A)</p> Signup and view all the answers

<p>Right atrium (A)</p> Signup and view all the answers

<p>Pulmonic valve (B)</p> Signup and view all the answers

<p>The heart's ability to pump more blood with increased venous return. (C)</p> Signup and view all the answers

<p>Diastole (C)</p> Signup and view all the answers

<p>To provide structural support and keep the chambers separate (C)</p> Signup and view all the answers

<p>Cardiac syncytium (B)</p> Signup and view all the answers

<p>Aorta (D)</p> Signup and view all the answers

<p>Elasticity (A)</p> Signup and view all the answers

<p>Allows the heart to beat even if there is damage to the nervous system. (D)</p> Signup and view all the answers

<p>The atria contract first, followed by the ventricles. (C)</p> Signup and view all the answers

<p>They can either increase or decrease the refractory period, depending on the specific drug and its intended effect. (D)</p> Signup and view all the answers

<p>They are found only in the sinoatrial (SA) node. (C)</p> Signup and view all the answers

<p>To slow down the impulse, allowing for atrial contraction and ventricular filling. (A)</p> Signup and view all the answers

<p>Phase 2: Plateau (C)</p> Signup and view all the answers

<p>The intrinsic ability of cardiac cells to generate electrical impulses independently. (D)</p> Signup and view all the answers

<p>Pericardium (B)</p> Signup and view all the answers

<p>To deliver the impulse to the ventricular muscle cells, stimulating contraction. (B)</p> Signup and view all the answers

<p>Automaticity (D)</p> Signup and view all the answers

<p>Influx of calcium ions into the cell. (D)</p> Signup and view all the answers

<p>To allow the ventricles to fill with blood before they contract. (A)</p> Signup and view all the answers

<p>Phase 0 (A)</p> Signup and view all the answers

<p>They prevent the backflow of blood during contraction. (D)</p> Signup and view all the answers

<p>Bundle of His - Ventricular septum (A)</p> Signup and view all the answers

<p>To allow for the coordinated contraction of the atria followed by the ventricles. (B)</p> Signup and view all the answers

<p>To conduct impulses through the ventricular muscle. (C)</p> Signup and view all the answers

<p>A pacemaker that is located outside of the sinoatrial (SA) node. (C)</p> Signup and view all the answers

<p>To allow blood flow from the right atrium to the right ventricle (C)</p> Signup and view all the answers

<p>Systole (D)</p> Signup and view all the answers

<p>Tricuspid valve (A)</p> Signup and view all the answers

<p>Sinoatrial (SA) node (D)</p> Signup and view all the answers

<p>Delays impulses for optimal atrial contraction (D)</p> Signup and view all the answers

<p>The capacity to generate action potentials spontaneously (D)</p> Signup and view all the answers

<p>They deliver impulses to stimulate ventricular contraction. (A)</p> Signup and view all the answers

<p>Sodium gates open, causing depolarization. (B)</p> Signup and view all the answers

<p>To maintain blood flow in one direction (B)</p> Signup and view all the answers

<p>The heart fills with blood as it relaxes. (D)</p> Signup and view all the answers

<p>It can lead to irregular heart rhythms. (D)</p> Signup and view all the answers

<p>They have the ability to generate action potentials spontaneously. (B)</p> Signup and view all the answers

<p>Bundle of His (A)</p> Signup and view all the answers

<p>To maintain resting membrane potential (B)</p> Signup and view all the answers

<p>Phase 3 (B)</p> Signup and view all the answers

<p>It depolarizes faster than any other cardiac cell (C)</p> Signup and view all the answers

<p>A time during which a second action potential cannot be stimulated (B)</p> Signup and view all the answers

<p>Aorta (B)</p> Signup and view all the answers

<p>Cardiac muscle cells can conduct impulses rapidly through specialized fibers (B)</p> Signup and view all the answers

<p>Calcium enters the cell while sodium and potassium leave (B)</p> Signup and view all the answers

<p>The distribution of ions across the membrane (A)</p> Signup and view all the answers

<p>They keep blood flowing in one direction (D)</p> Signup and view all the answers

<p>It triggers the contraction of cardiac muscle (B)</p> Signup and view all the answers

<p>They can alter responsiveness to stimuli (A)</p> Signup and view all the answers

<p>SA node (C)</p> Signup and view all the answers

<p>Automaticity (A)</p> Signup and view all the answers

<p>Phase 0 (B)</p> Signup and view all the answers

<p>To prevent backflow of blood from arteries into ventricles (C)</p> Signup and view all the answers

<p>Phase 2 (A)</p> Signup and view all the answers

<p>To maintain ionic balance (D)</p> Signup and view all the answers

<p>SA node (D)</p> Signup and view all the answers

<p>To rapidly conduct impulses to ventricular cells (B)</p> Signup and view all the answers

<p>Refractory period (C)</p> Signup and view all the answers

<p>AV node (B)</p> Signup and view all the answers

<p>Decreased potassium efflux and sodium leakage (C)</p> Signup and view all the answers

<p>Longer duration due to plateau phase (B)</p> Signup and view all the answers

<p>Pacemakers arising from the AV node or Purkinje fibers (C)</p> Signup and view all the answers

<p>Potassium rapidly exits the cell (A)</p> Signup and view all the answers

<p>Thanks to the automaticity of pacemaker cells (B)</p> Signup and view all the answers

<p>It allows the ventricles to fill completely before contraction. (B)</p> Signup and view all the answers

<p>Myocardium (C)</p> Signup and view all the answers

<p>It is essential for maintaining the heart rate. (B)</p> Signup and view all the answers

<p>P-R interval (D)</p> Signup and view all the answers

<p>They are completely unresponsive to subsequent stimuli. (B)</p> Signup and view all the answers

<p>To set the pace for heart rate through spontaneous depolarization. (B)</p> Signup and view all the answers

<p>They can prolong or shorten the refractory period. (C)</p> Signup and view all the answers

<p>Ventricular depolarization (D)</p> Signup and view all the answers

<p>Purkinje fibers (D)</p> Signup and view all the answers

<p>The left heart receives oxygenated blood. (D)</p> Signup and view all the answers

<p>Right ventricle (B)</p> Signup and view all the answers

<p>Any disruption in the normal rate or rhythm of the heart. (C)</p> Signup and view all the answers

<p>Prevent blood from flowing back into the ventricles. (C)</p> Signup and view all the answers

<p>The heart rate is within the normal range for the individual's age. (A)</p> Signup and view all the answers

<p>Diastole (D)</p> Signup and view all the answers

<p>It can increase or decrease the rate of action potentials. (D)</p> Signup and view all the answers

<p>Greater stretching of the heart muscle results in stronger contractions. (A)</p> Signup and view all the answers

<p>At the end of the T wave. (D)</p> Signup and view all the answers

<p>Pulmonary veins (B)</p> Signup and view all the answers

<p>Automaticity (C)</p> Signup and view all the answers

<p>Vena cavae → Right atrium → Right ventricle (B)</p> Signup and view all the answers

<p>It prevents oxygenated and deoxygenated blood from mixing. (A)</p> Signup and view all the answers

<p>They close tightly to prevent backflow into the atria. (B)</p> Signup and view all the answers

<p>Left ventricle (C)</p> Signup and view all the answers

<p>Blood is pushed into the ventricles. (D)</p> Signup and view all the answers

<p>They collect blood before it enters the ventricles. (D)</p> Signup and view all the answers

<p>To prevent backflow into the left ventricle. (A)</p> Signup and view all the answers

<p>Annulus (C)</p> Signup and view all the answers

<p>Automaticity (A)</p> Signup and view all the answers

<p>Atrioventricular (AV) node (D)</p> Signup and view all the answers

<p>Slow influx of calcium ions (A)</p> Signup and view all the answers

<p>Phase 0 (B)</p> Signup and view all the answers

<p>It has the fastest rate of automaticity among the cardiac cells. (B)</p> Signup and view all the answers

<p>It allows the chambers to fill with blood. (B)</p> Signup and view all the answers

<p>To deliver the electrical impulse to the ventricular cells for contraction. (B)</p> Signup and view all the answers

<p>All of the above (D)</p> Signup and view all the answers

<p>A greater blood volume leads to a stronger contraction. (A)</p> Signup and view all the answers

<p>To generate electrical impulses for heart contractions. (B)</p> Signup and view all the answers

<p>It ensures a prolonged contraction of the heart muscle. (D)</p> Signup and view all the answers

<p>It prevents the premature contraction of the heart. (C)</p> Signup and view all the answers

<p>It helps to maintain the resting membrane potential by pumping sodium out and potassium into the cell. (C)</p> Signup and view all the answers

<p>To ensure that the heart continues to function even in life-threatening situations. (C)</p> Signup and view all the answers

<p>Blood is pumped into the systemic and pulmonary circulation. (B)</p> Signup and view all the answers

<p>The SA node has the fastest rate of automaticity, followed by the AV node and then the ventricular muscle cells. (A)</p> Signup and view all the answers

<p>They remain open to allow blood flow into the ventricles. (D)</p> Signup and view all the answers

<p>It ensures the heart can beat regardless of brain activity. (C)</p> Signup and view all the answers

<p>To transmit the electrical impulse from the SA node to the AV node. (B)</p> Signup and view all the answers

<p>Diastole refers to the relaxation phase of the heart, during which automaticity is increased. (C)</p> Signup and view all the answers

<p>The Purkinje fibers. (D)</p> Signup and view all the answers

<p>They close tightly to prevent backflow. (C)</p> Signup and view all the answers

<p>Pale cells (P cells) (D)</p> Signup and view all the answers

<p>It conducts the electrical impulse from the atria to the ventricles. (A)</p> Signup and view all the answers

<p>Blood follows a specific one-way path through the heart. (B)</p> Signup and view all the answers

<p>It can be stretched and always returns with strength. (C)</p> Signup and view all the answers

<p>It ensures a prolonged contraction of the heart muscle. (D)</p> Signup and view all the answers

<p>The synchronized contraction of atria and ventricles. (A)</p> Signup and view all the answers

<p>It has three leaflets or cusps. (B)</p> Signup and view all the answers

<p>Atrial pressure must be greater than ventricular pressure. (A)</p> Signup and view all the answers

<p>The aorta is the primary vessel for leaving the heart. (B)</p> Signup and view all the answers

<p>Their openings are covered by the aortic valve leaflets. (B)</p> Signup and view all the answers

<p>Heart rate. (C)</p> Signup and view all the answers

<p>Potential ischemia of the heart muscle. (D)</p> Signup and view all the answers

<p>Most of the left lateral wall of the ventricle. (C)</p> Signup and view all the answers

<p>Increases the volume of blood returned to the heart. (D)</p> Signup and view all the answers

<p>The difference between systolic and diastolic blood pressure. (C)</p> Signup and view all the answers

<p>It represents the resistance the heart must overcome to pump blood. (C)</p> Signup and view all the answers

<p>During diastole. (A)</p> Signup and view all the answers

<p>Most of the right side of the heart. (C)</p> Signup and view all the answers

<p>It efficiently meets the heart muscle's needs under normal circumstances. (C)</p> Signup and view all the answers

<p>Exercise or stress (A)</p> Signup and view all the answers

<p>All cardiac cells possess a degree of automaticity, meaning they can spontaneously generate action potentials. (A)</p> Signup and view all the answers

<p>Sinus bradycardia (D)</p> Signup and view all the answers

<p>Phase 0 (D)</p> Signup and view all the answers

<p>They show normal QRS complexes. (C)</p> Signup and view all the answers

<p>Atrioventricular (AV) node (D)</p> Signup and view all the answers

<p>Third-degree block (C)</p> Signup and view all the answers

<p>Fewer QRS complexes than P waves. (B)</p> Signup and view all the answers

<p>Irregular contractions lacking coordination. (B)</p> Signup and view all the answers

<p>Absolute refractory period (C)</p> Signup and view all the answers

<p>The SA node initiates and regulates the heart's rhythm (D)</p> Signup and view all the answers

<p>Ineffective pumping of blood. (D)</p> Signup and view all the answers

<p>Long QT interval. (D)</p> Signup and view all the answers

<p>Conductivity (B)</p> Signup and view all the answers

<p>Followed by a compensatory pause. (B)</p> Signup and view all the answers

<p>Rapid efflux of potassium ions (C)</p> Signup and view all the answers

<p>Supplies oxygen and nutrients to the heart muscle. (D)</p> Signup and view all the answers

<p>An ectopic pacemaker would likely take over. (C)</p> Signup and view all the answers

<p>Ectopic pacemaker (D)</p> Signup and view all the answers

<p>Atrial fibrillation (C)</p> Signup and view all the answers

<p>Ectopic foci in the ventricles. (C)</p> Signup and view all the answers

<p>The autonomic nervous system modulates the heart rate and force of contraction. (C)</p> Signup and view all the answers

<p>Automaticity (A)</p> Signup and view all the answers

<p>Right ventricle (D)</p> Signup and view all the answers

<p>Decreases oxygen demand. (B)</p> Signup and view all the answers

<p>Phase 2 (D)</p> Signup and view all the answers

<p>It has a longer duration than the action potential of a SA node cell. (B)</p> Signup and view all the answers

<p>The refractory period occurs during the plateau phase of the action potential. (B)</p> Signup and view all the answers

<p>It momentarily rises until it exceeds the pressure in the right ventricle. (A)</p> Signup and view all the answers

<p>To control blood flow by adjusting resistance. (B)</p> Signup and view all the answers

<p>To facilitate nutrient and gas exchange at the cellular level. (D)</p> Signup and view all the answers

<p>It pushes fluid out of the capillaries into the interstitial spaces. (D)</p> Signup and view all the answers

<p>Edema (D)</p> Signup and view all the answers

<p>The venous system is a capacitance system with the capacity to hold more blood. (B)</p> Signup and view all the answers

<p>To deliver oxygenated blood to the heart muscle. (C)</p> Signup and view all the answers

<p>Oncotic pressure pulls fluid back into the capillaries. (D)</p> Signup and view all the answers

<p>It transports deoxygenated blood from the right ventricle to the lungs. (A)</p> Signup and view all the answers

<p>It is at its maximum level due to blood return from the body. (C)</p> Signup and view all the answers

<p>Arteries have thick, muscular walls that provide strength. (D)</p> Signup and view all the answers

<p>It creates dependency on aerobic metabolism for energy. (A)</p> Signup and view all the answers

<p>The presence of one-way valves preventing backflow. (C)</p> Signup and view all the answers

<p>The diameter changes in arterioles. (B)</p> Signup and view all the answers

The structure of the heart, including chambers, valves, and vessels.

The sequence of blood movement through the heart during one heartbeat.

The system that controls the heart's rhythm through electrical signals.

A graphical representation of the heart's electrical activity over time.

Movement of fluid between capillaries and surrounding tissues influenced by pressure and concentration.

Cells in the AV node or Purkinje fibers that discharge impulses faster than the SA node.

The ability of cardiac cells to generate impulses without external stimuli.

The five distinct phases during electrical impulse generation in cardiac cells.

Depolarization phase where sodium rushes into the cell.

Repolarization begins as sodium channels close and potassium starts to leave.

Plateau phase characterized by calcium entering and potassium leaving slowly.

Rapid repolarization where potassium rapidly moves out and calcium influx stops.

Resting membrane potential is achieved by the sodium-potassium pump.

The natural pacemaker of the heart, generating impulses 90-100 times a minute.

Serves as a backup pacemaker generating impulses 40-50 times a minute.

The property that allows cardiac cells to conduct impulses rapidly throughout the heart.

The speed at which electrical impulses travel through the heart's conduction system.

Time after an action potential where cells cannot be stimulated again.

The volume of blood the heart pumps per minute; crucial for circulation.

To pump blood, delivering oxygen and nutrients while removing wastes.

Thin filament that is a component of a sarcomere, or muscle unit.

Hormone from the adrenal cortex that increases retention of sodium and water in the kidneys.

Peptide hormone that causes vasoconstriction and stimulates aldosterone and ADH release.

Hormone that increases water retention in the kidneys, released from the posterior pituitary.

Disruption in cardiac rate or rhythm, also called dysrhythmia.

Period of diastole (relaxation) followed by systole (contraction) in the heart.

The resting phase of the heart where blood returns to the heart.

The contracting phase of the heart during which blood is pumped out.

The muscle of the heart responsible for contraction.

The functional unit of a muscle cell, composed of actin and myosin.

A chemical in heart muscle that controls actin and myosin interaction.

Vessels that return blood to the heart; they are distensible tubes.

Lower chambers of the heart that pump blood out to the lungs or body.

The normal pacemaker of the heart, generating spontaneous action potentials.

Muscle fibers forming the myocardium of the heart.

Network of cardiac fibers allowing simultaneous atrial contraction.

Network facilitating concurrent contraction of the ventricles.

Simultaneous contraction of cardiac muscle due to a single stimulus.

The heart's ability to contract stronger when filled more completely.

Heart valve between right atrium and right ventricle.

Valve between left atrium and left ventricle, has two leaflets.

Network managing electrical impulses to trigger heartbeats.

Natural pacemaker generating action potentials for heartbeat.

Slows impulses from atria before passing to ventricles.

Fibers that conduct impulses to ventricular muscle for contraction.

The right side of the heart that receives deoxygenated blood.

The left side of the heart that pumps oxygenated blood to the body.

Upper chambers of the heart that collect blood.

An appendage attached to each atrium that collects blood.

Thin tissues that ensure blood flows in one direction in the heart.

Partition that separates the right and left sides of the heart.

Blood low in oxygen returning to the heart from the body.

Blood rich in oxygen coming from the lungs to the heart.

The greater the heart muscle is stretched, the stronger it contracts.

The normal heart rhythm set by the SA node.

The ability of cardiac cells to conduct impulses rapidly.

A delay in impulse conduction at the AV node between atria and ventricles.

Conduct impulses rapidly for simultaneous ventricle contraction.

The four sections of the heart: two atria and two ventricles.

The more the heart fills, the stronger the contraction.

The pathway for deoxygenated blood to the lungs.

The pathway for oxygenated blood to the body tissues.

Cells that set the heart's rhythm by generating impulses.

A collection of heart muscle cells that conduct impulses from the AV node to the ventricles.

Electrical impulses in cardiac cells, allowing for contraction.

The network of cells that transmits electrical signals throughout the heart.

The heart's ability to beat independently of brain signals when nourished.

Valve controlling blood flow from right ventricle to pulmonary artery.

Valve controlling blood flow from left ventricle to aorta.

Primitive cardiac cells capable of generating action potentials without external stimuli.

Spontaneous depolarization during diastole as potassium flow decreases.

The state of a cardiac cell when it's not actively transmitting an impulse.

A pump that maintains resting membrane potential by moving sodium out and potassium in.

A unique phase in cardiac muscle action potentials that prolongs depolarization.

Rapid repolarization where calcium influx stops and potassium exits the cell.

The stable, resting state of a cardiac cell after depolarization.

The SA node generates electrical impulses at 90-100 beats per minute.

Acts as a backup pacemaker, generating impulses 40-50 times a minute.

Generate impulses only about 10-20 times a minute.

The ability of heart cells to conduct impulses rapidly.

A delay in impulse conduction at AV node allowing atria to contract before ventricles.

Consists of the heart and interconnected blood vessels for movement of blood.

The heart is divided into right (deoxygenated blood) and left (oxygenated blood) sides.

The process through which electrical impulses control heartbeats.

The movement of electrical signals through the heart’s conducting system.

The process of restoring the resting membrane potential after depolarization.

The entry of calcium ions during the plateau phase of action potential.

Ions that move out of the cell during repolarization.

The body system responsible for delivering oxygen and nutrients and removing wastes.

The action of the atria contracting to push blood into the ventricles.

A system with no openings allowing blood leakage, ensuring pressure regulation.

Blood flows from high pressure to low pressure areas in circulation.

Collects deoxygenated blood from the body to be sent to the right ventricle.

Receives oxygenated blood from the lungs and sends it to the left ventricle.

Phase where blood quickly flows from the right atrium to the right ventricle.

Condition of fluid retention in tissue due to pressure imbalance.

The arterial system that offers resistance to blood flow, regulating pressure.

Constant supply of oxygenated blood to the heart muscle through coronary arteries.

Returns fluids from tissues back to the circulatory system.

Pulling pressure of proteins in blood that helps retain fluid in capillaries.

Force exerted by fluids pushing against capillary walls, driving fluid out.

Artery that arises from the left aorta and bifurcates into two branches.

A branch of the left coronary artery that supplies the left lateral wall of the ventricle.

A branch of the left coronary artery that supplies the anterior parts of the heart.

Artery that arises from the right side of the aorta, supplying the right heart.

The difference between systolic and diastolic blood pressure, indicating artery pressure.

Circulation pattern where arteries supply specific areas without significant backup circulation.

The volume of blood returned to the heart before it pumps, affecting contraction strength.

The resistance the heart must overcome to eject blood during contraction.

A heart rate faster than 100 beats/min with a normal ECG.

A slower heart rate, usually less than 60 beats/min with a normal ECG.

A temporary stoppage of SA node signaling leading to ectopic pacemaker takeover.

Arrhythmias originating above the ventricles but not in the SA node.

Early heartbeats formed from an ectopic focus in the atria.

Sudden bursts of rapid heart rate originating in the atria.

Fast atrial depolarization characterized by sawtooth P waves.

Irregular and fast heart rhythm due to many ectopic foci firing.

Disruption in impulse conduction at the AV node.

All impulses reach ventricles but delayed, characterized by a long P-R interval.

Arrhythmias originating below the AV node with wide QRS complexes.

Early heartbeats from ectopic foci in the ventricles, can have varying shapes.

A type of polymorphic ventricular tachycardia with QRS polarity that twists.

Uncoordinated electrical activity in ventricles, leading to ineffective pumping.

Blood flow supplying the heart muscle with oxygen and nutrients.

The gradual depolarization that occurs in SA node cells leading to action potential generation.

The technique of recording the electrical activity of the heart during the cardiac cycle.

The P wave, QRS complex, and T wave represent the heart’s electrical activity.

The time from the beginning of the P wave to the start of the QRS complex, indicating AV nodal delay.

A variation in heart rate that occurs naturally with breathing.