The Cardiac Cycle

Part A

Complete the following statements:

1. The period during which a heart chamber is contracting is called_.

2. The period during which a heart chamber is relaxing is called_.

3. During ventricular contraction, the A-V valves (tricuspid and bicuspid valves) remain_.

4. During ventricular relaxation, the A-V valves remain_.

5. The pulmonary and aortic valves open when the pressure in the_exceeds the pressure in the pulmonary trunk and aorta.

6. The first sound of a cardiac cycle occurs when the_are closing.

7. The second sound of a cardiac cycle occurs when the_are closing.

8. The sound created when blood leaks back through an incompletely closed valve is called a

Part B

Complete the following: 1. What changes did you note in the heart sounds when you inhaled deeply?

2. What changes did you note in the heart sounds following the exercise period?

Part C

Complete the following statements:

1. Normally, the_node serves as the pacemaker of the heart.

2. The_node is located in the inferior portion of the interatrial septum.

3. The large fibers on the distal side of the A-V node make up the_.

4. The fibers that carry cardiac impulses from the interventricular septum into the myocardium are called

5. An_is a recording of electrical changes occurring in the myocardium during a cardiac cycle.

6. The P wave corresponds to depolarization of the muscle fibers of the_.

7. The QRS complex corresponds to depolarization of the muscle fibers of the_.

8. The T wave corresponds to repolarization of the muscle fibers of the_.

9. Why is atrial repolarization not observed in the ECG? _

Part D

1. Attach a short segment of the ECG recording from each of the three leads you used and label the waves of each. Lead I

Lead II

Lead III

2. What differences do you find in the ECG patterns of these leads?

3. How much time passed from the beginning of the P wave to the beginning of the QRS complex (P-Q interval, or P-R interval) in the ECG from Lead I? _

4. What is the significance of this P-Q (P-R) interval? _

5. How can you determine the heart rate from an electrocardiogram?

6. What was your heart rate as determined from the ECG?

? ft« Critical Thinking Application

If a person's heart rate is 72 beats per minute, determine the number of QRS complexes that would have appeared on an ECG during the first 30 seconds.

43. Factors Affecting the Cardiac Cycle

Text

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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Responses

  • gruffo
    What changes did you note in the heart souns when you inhaled deeply?
    5 years ago
  • primrose
    What changes did you note in the heart sounds when you inhaled deeply quizlet?
    5 years ago
  • George
    What changes did you note in the heart sounds when you inhaled deepky?
    4 years ago
  • Ellie-louise
    What changes did you note in the heart sound when you inhale deeply?
    4 years ago
  • callisto
    What change did you note in the heart sounds when you inhaled deeply?
    3 years ago
  • teija
    WHAT CHANGES DO YOU NOTE IN A HEART SOUND WHEN YOU INIHALE DEEPLY?
    2 years ago
  • MATTIA
    What differences do you find in the ECG patterns of these leads?
    2 years ago

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