Chapter 19- Heart Quiz

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

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.