Chapter 19- Heart  Quiz
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Chapter 19- Heart Quiz

Test your knowledge of the refractory period in neurons and muscle fibers with this quiz! Learn about the temporary state of reduced excitability and the inability to generate another action potential during this period.

Created by
@MajesticNovaculite

Questions and Answers

Which of the following is NOT a component of the cardiovascular system?

Lungs

What is the function of capillaries in the cardiovascular system?

To facilitate exchange of substances between the bloodstream and surrounding tissues

Which layer of the heart is composed of cardiac muscle?

Myocardium

What is the function of the valves in the heart?

<p>To ensure unidirectional flow of blood through the heart chambers</p> Signup and view all the answers

Which chamber of the heart receives deoxygenated blood from the body and pumps it to the right ventricle?

<p>Right Atrium</p> Signup and view all the answers

What is the function of the myocardium?

<p>Responsible for contracting and pumping blood throughout the body</p> Signup and view all the answers

Which layer of the heart wall provides a protective outer covering to the heart?

<p>Epicardium</p> Signup and view all the answers

What is the main function of the aortic valve?

<p>Prevents the backflow of blood from the aorta into the left ventricle</p> Signup and view all the answers

Which coronary artery supplies blood to the lateral wall of the left ventricle?

<p>Circumflex Artery (Cx)</p> Signup and view all the answers

Which coronary artery supplies blood to the posterior walls of both ventricles?

<p>Posterior Descending Artery (PDA)</p> Signup and view all the answers

Where is the AV Node located?

<p>Lower portion of the right atrium near the septum</p> Signup and view all the answers

What is the primary neurotransmitter released by sympathetic innervation of the heart?

<p>Norepinephrine</p> Signup and view all the answers

Which of the following is responsible for maintaining the negative charge inside a nodal cell?

<p>Higher concentration of negatively charged ions</p> Signup and view all the answers

What is the primary ion responsible for regulating the resting membrane potential of a nodal cell?

<p>Potassium (K+)</p> Signup and view all the answers

What is autorhythmicity?

<p>The ability of cells to generate spontaneous electrical impulses</p> Signup and view all the answers

What role does the SA node play in the spread of the action potential through the heart?

<p>Initiates the action potential</p> Signup and view all the answers

During which phase of the cardiac cycle do the semilunar valves open and blood is forced into the arterial trunk?

<p>Late ventricular systole</p> Signup and view all the answers

What is the purpose of the refractory period in a neuron or muscle fiber?

<p>To prevent tetany in cardiac muscle cells</p> Signup and view all the answers

What is the significance of ventricular balance in the heart?

<p>It allows for efficient pumping of blood</p> Signup and view all the answers

What is the formula for calculating cardiac output?

<p>Stroke volume multiplied by heart rate</p> Signup and view all the answers

Which of the following best defines cardiac reserve?

<p>The difference between a person's resting cardiac output and their maximum achievable cardiac output</p> Signup and view all the answers

What are chronotropic agents?

<p>Positive and negative variables that affect heart rate</p> Signup and view all the answers

Which of the following is a positive chronotropic agent?

<p>Increased demand during physical exertion</p> Signup and view all the answers

Which of the following is a negative chronotropic agent?

<p>Decreased demand during physical exertion</p> Signup and view all the answers

How do autonomic reflexes alter heart rate?

<p>By receiving sensory input from baroreceptors and chemoreceptors</p> Signup and view all the answers

What are the key extrinsic variables that raise and decrease heart rate?

<p>Autonomic nervous system innervation and fluctuating hormone levels</p> Signup and view all the answers

Which of the following is NOT a function of the fibrous skeleton in the heart?

<p>Formation of valves</p> Signup and view all the answers

What is the primary function of the mitral valve?

<p>Regulate blood flow between the left atrium and left ventricle</p> Signup and view all the answers

What is the main source of energy for cardiac muscle?

<p>Adenosine triphosphate (ATP)</p> Signup and view all the answers

What is the function of intercalated discs in cardiac muscle?

<p>Facilitate electrical coupling</p> Signup and view all the answers

Which valve regulates blood flow between the left atrium and left ventricle?

<p>Mitral valve</p> Signup and view all the answers

What is the function of the fibrous skeleton in the heart?

<p>To provide structural support</p> Signup and view all the answers

What is the main source of energy for cardiac muscle?

<p>Adenosine triphosphate (ATP)</p> Signup and view all the answers

What is the function of intercalated discs in cardiac muscle?

<p>To facilitate electrical coupling</p> Signup and view all the answers

Study Notes

Components of the Cardiovascular System

  • The lymphatic system is NOT a component of the cardiovascular system

Capillaries in the Cardiovascular System

  • Capillaries are responsible for exchanging oxygen and nutrients with cells and removing waste products

Heart Structure

  • The myocardium is the layer of the heart composed of cardiac muscle
  • The epicardium is the layer of the heart wall that provides a protective outer covering to the heart

Heart Valves

  • The function of valves in the heart is to ensure one-way blood flow and prevent backflow
  • The aortic valve allows blood to flow from the left ventricle into the aorta and prevents backflow
  • The mitral valve regulates blood flow between the left atrium and left ventricle

Heart Chambers

  • The right atrium receives deoxygenated blood from the body and pumps it to the right ventricle

Blood Supply

  • The obtuse marginal branch of the left circumflex artery supplies blood to the lateral wall of the left ventricle
  • The posterior descending branch of the right coronary artery supplies blood to the posterior walls of both ventricles

Electrical Conduction

  • The AV Node is located in the inferior portion of the right atrium
  • The primary neurotransmitter released by sympathetic innervation of the heart is norepinephrine
  • The negative charge inside a nodal cell is maintained by potassium ions
  • The primary ion responsible for regulating the resting membrane potential of a nodal cell is potassium
  • Autorhythmicity is the ability of certain cardiac cells to generate an electrical impulse spontaneously
  • The SA node plays a role in the spread of the action potential through the heart by generating an electrical impulse that travels to the AV Node

Cardiac Cycle

  • During the ejection phase of the cardiac cycle, the semilunar valves open and blood is forced into the arterial trunk

Refractory Period

  • The refractory period in a neuron or muscle fiber is the period during which it cannot respond to a new stimulus

Cardiac Output

  • Cardiac reserve is the difference between the maximum cardiac output and the resting cardiac output
  • The formula for calculating cardiac output is cardiac output = heart rate x stroke volume
  • Chronotropic agents are substances that alter the heart rate
  • Positive chronotropic agents increase heart rate, while negative chronotropic agents decrease heart rate
  • Autonomic reflexes alter heart rate through the stimulation of the sympathetic or parasympathetic nervous system
  • The key extrinsic variables that raise and decrease heart rate are sympathetic and parasympathetic stimulation, respectively

Fibrous Skeleton

  • The fibrous skeleton in the heart provides a framework for the attachment of the heart valves and separates the atria from the ventricles

Energy for Cardiac Muscle

  • The primary source of energy for cardiac muscle is ATP derived from fatty acid oxidation
  • Intercalated discs in cardiac muscle allow for the rapid transmission of electrical impulses between cells

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