lab 3 ecg

• What is the property of cardiocytes that allows them to contract without neural or hormonal stimulation?

  The property is known as automaticity or autorhythmicity.
• Where does the conduction pathway begin, and what is its initial action potential generator??

   The conduction pathway begins with the Sinoatrial (SA) node, which serves as the internal pacemaker.
• What happens if the SA node is damaged, and what is the resulting rhythm called?

  If the SA node is damaged, the AV node may take control, resulting in a normal but slower heartbeat, known as nodal rhythm.
• What does an electrocardiogram (EKG or ECG) represent, and what are the five identifiable waves in a typical tracing?

  An EKG represents the electrical events in the heart. The five waves are P, Q, R, S, and T.
• 1. Unlike skeletal muscle, cardiac tissue exhibits automaticity, allowing it to contract without neural or hormonal stimulation.
• 1. The conduction pathway begins with the Sinoatrial (SA) node, located near the entrance of the superior vena cava in the posterior wall of the right atrium.
• 1. If the SA node is damaged, the Atrioventricular (AV) node may take over control, resulting in a normal but slower heart rate, known as nodal rhythm.
• Atrial depolarization causes the P wave on the EKG.
• 1. The P wave in an EKG tracing represents the depolarization of the heart's atria(the process of the heart muscle cells preparing to contract), while the QRS complex represents the depolarization of the heart's ventricles. (the lower chambers of the heart contracting).
• 1. The PR interval on an EKG represents the period from the start of atrial depolarization to the start of ventricular depolarization, while the QT interval represents the time for the ventricles to depolarize and repolarize in a single cycle.
• 1. The ST segment in an EKG represents the ventricles in a depolarized state prior to repolarization.
• What is T wave? It represents the repolarization of the ventricles before ventricular diastole (relaxation).
• Find the segment, interval and etc.

  A) PR interval

  B) QT interval

  C) PR segment

  D) ST segment

  E) QRS Complex

  
• Explain a regular heartbeat? During each heartbeat, a healthy heart will have an orderly progression of a wave of depolarization triggered by the SA node (P wave) across the atria, passing through the AV node, and then spreading all over the ventricles (QRS complex) followed by repolarization of the ventricles (T wave)
• type where the atria and ventricle contract

  A) Atria Contract

  B) Ventricle Contract

  C) Ventricle Contract

  D) Atria contract

  
• P wave: Depolarization of atrial fibers at SA node
• PR interval: The Time from beginning of depolarization(P wave) of atrial fibers to beginning of depolarization of the ventricles(QRS complex)
• PQ segment: Time for cardiac impulse to pass through the AV node.
• ST Segment:Time for ventricles to contract
• QT interval: Time from ventricular depolarization to end of ventricular repolarization
• T wave: Repolarization of ventricular fibers
• TP segment: Time of relaxation and filling of the heart between beats
• Name these

  A) PR Interval

  B) PQ segment

  C) ST segment

  D) RR interval

  E) TP segment

  F) P wave

  G) R wave

  H) T wave

  I) Q wave

  J) QRS complex

  K) S wave

  L) QT interval

  
• If heart rate increases, what changes would you expect to see in the ECG?

  • The Q-T interval increases.
  • The QRS amplitude increases.
  • The R-R interval decreases.

  The R-R interval decreases.
• Longer intervals (of any type) would indicate a slower heart rate.
• Which of the following correctly describes the electrode placements in the Einthoven's triangle arrangement?

  One on each wrist and one on the left ankle.
• what happens to the heart rate as the R-R interval decreases?

  The heart rate increases.
• Which time interval could be used to calculate the heart rate?

  r wave and the next r wave
• If the action potentials do not change and the timing between the atrial and ventricular action potentials remains constant, which time interval will change when the heart rate increases?

  The time interval between T-wave and the next P-wave
• The electrocardiogram (ECG) measures:

  action potentials in the atria and the ventricles.
• If the heart were in the midline of the chest, then the distance between the heart and each electrode in Lead I orientation would be:

  the same
• The action potential passes from the SA node to the ventricles via:


  the atrioventricular (AV) node.
• How does an action potential travel from Brian’s AV node to the two ventricles?

  Through the AV bundle, bundle branches, and Purkinje fibers
• what is the abnormal heart rate called?

  arrhythmia is an abnormal heart rhythm
• In most people, the heart is located:

  To left of the midline
• The heart lies in the thorax with its long axis


  pointing downward, at some angle between horizontal and vertical.
• The amplitude of the QRS complex in Lead I is smaller than the amplitude of the QRS complex in Lead II. This is because:


  the distance between the two wrists is shorter.
• The amplitude of the QRS complex in Lead I is smaller than the amplitude of the QRS complex in Lead II. This is because: --the distance between the two wrists is shorter. --the distance between the right wrist and left ankle is larger. --Both options are correct. 


  Both options are correct.
• An action potential travels from the AV node to the ventricles by: --gap junctions between the AV node and the ventricular fibers. --specialized myocytes. --the autonomic nervous system. --specialized nerves in the heart.

  specialized myocytes
• what is the probe touching ?


  acsending Aorta