Ch. 17 - Cardiovascular Physiology I: The HeartSee all chapters
All Chapters
Ch. 1 - Introduction to Physiology
Ch. 2 - Molecules and Molecular Interactions
Ch. 3 - Cells and Tissues
Ch. 4 - Cell Metabolism: Bioenergetics, Enzymes, and Respiration
Ch. 5 - Membrane Dynamics
Ch. 6 - Cell Communication
Ch. 7 - Integumentary System
Ch. 8 - Bone and Cartilage
Ch. 9 - Skeletal System
Ch. 10 - Joints
Ch. 11 - Muscles
Ch. 12 - The Nervous System I: Neurons and Neuronal Networks
Ch. 13 - The Nervous System II: The Central Nervous System
Ch. 14 - The Autonomic Nervous System
Ch. 15 - Sensory Physiology
Ch. 16 - The Endocrine System
Ch. 17 - Cardiovascular Physiology I: The Heart
Ch. 18 - Cardiovascular Physiology II: Blood, Blood Vessels, Circulation, and Exchange
Ch. 19 - The Urinary System
Ch. 20 - Respiratory Physiology
Ch. 21 - Acid-Base Balance-- Controlling Blood pH
Ch. 22 - Introduction to the Immune System
Ch. 23 The Lymphatic System
Ch. 23 - The Digestive System
Ch. 24 - Regulation of Metabolism and Energy Balance
Ch. 25 - Human Sexual Reproduction and Development

Concept #1: Cardiac Muscle Action Potentials

Practice: Lidocaine is a drug that blocks voltage-gated Na+ channels. Which of the following phases of a cardiac action potential will be directly affected by the administration of lidocaine?

Practice: Verapamil is a drug that blocks voltage-gated Ca2+ channels. Which of the following phases of a cardiac action potential will be directly affected by the administration of verapamil?

Practice: Electrocardiograms (EKG) are recordings of the heart’s electrical activity made from the skin. The QRS complex of an EKG is caused by the depolarization phase of cardiac action potentials. Which of the following phases of a cardiac action potential causes the QRS complex in an EKG recording?