CVS Questions: Trivia Quiz! Exam

The correct answer is SA node - AV node - Bundle of His - Purkinje fibres. This sequence is the correct pathway for the normal sequence of excitation to progress through the heart. The SA node, located in the right atrium, initiates the electrical impulse that signals the heart to contract. The impulse then travels to the AV node, located at the base of the right atrium, which acts as a gatekeeper, delaying the impulse to allow the atria to contract fully before the ventricles are stimulated. From the AV node, the impulse travels down the Bundle of His, a bundle of specialized cardiac muscle fibers, and then branches out into the Purkinje fibers, which spread the electrical signal throughout the ventricles, causing them to contract. This sequence ensures the coordinated contraction of the heart chambers, allowing for efficient blood pumping.

The left coronary artery is the main branch of the heart. It supplies oxygenated blood to the left side of the heart, including the left ventricle and left atrium. This artery branches into the circumflex artery, which supplies the left atrium and posterior wall of the left ventricle, and the left anterior descending artery (LAD), which supplies the front and bottom of the left ventricle. Therefore, the left coronary artery is the main branch responsible for supplying blood to a significant portion of the heart.

The vagus nerve is responsible for regulating the parasympathetic nervous system, which controls rest and digestion. Stimulation of the vagus nerve can slow down the heart rate, as it sends signals to the heart to decrease its activity. This is why the vagus nerve is often targeted in medical procedures to treat conditions such as arrhythmias or excessive heart rate.

The second heart sound represents the closing of the semilunar valves. These valves, which include the aortic and pulmonary valves, close after the ventricles have contracted and blood has been pumped out of the heart. This closure creates the "dub" sound that is heard during auscultation of the heart.

The thick muscle wall in the arterioles serves multiple functions. It controls the diameter of the small arteries, which in turn regulates the blood pressure and blood flow to the tissues. Additionally, the muscle wall also has a resistance function, allowing it to regulate the amount of blood that flows through the arterioles. Therefore, all of the given statements are correct and provide a comprehensive explanation of the role of the thick muscle wall in the arterioles.

The correct answer is "Responsible for the initiation and conduction of the action potential." This answer is supported by the fact that non-contractile fibers in the heart, specifically the specialized cardiac conduction system, are responsible for generating and transmitting electrical impulses that regulate the heartbeat. These fibers include the sinoatrial (SA) node, atrioventricular (AV) node, bundle of His, and Purkinje fibers. They coordinate the contraction of the heart muscle and ensure that it beats in a synchronized and efficient manner.

Cardiac output refers to the volume of blood that is pumped by the left ventricle of the heart into the aorta per minute. It is an important measure of the heart's efficiency in delivering oxygenated blood to the body's tissues. The other options, such as cardiac input, stroke volume, heart rate, and auscultation, are not directly related to the volume of blood ejected from the left ventricle into the aorta.

The pulmonary valve prevents blood from flowing back from the lungs. When the heart contracts, the pulmonary valve opens to allow blood to flow from the right ventricle to the lungs for oxygenation. Once the blood is oxygenated, the pulmonary valve closes to prevent the blood from flowing back into the right ventricle. This ensures that oxygen-rich blood is sent to the rest of the body through the aorta, rather than mixing with deoxygenated blood in the right ventricle.

The correct answer is "right marginal branch." The question is asking to identify the structure, and out of the given options, the right marginal branch is the correct answer. The right marginal branch is a branch of the right coronary artery, which is one of the main arteries supplying blood to the heart. It runs along the right border of the heart and supplies blood to the right ventricle.

The right pulmonary veins do not open into the right atrium.

The trachea is a tube-like structure that connects the larynx to the bronchi, allowing air to pass in and out of the lungs. It is located in the superior mediastinum, which is the upper part of the thoracic cavity. This region is situated between the sternum and the vertebral column, and it contains important structures such as the great vessels, thymus gland, and the trachea. Therefore, the correct answer is superior mediastinum.

The coronary sinus is a large vein that collects deoxygenated blood from the heart muscle and returns it to the right atrium of the heart. The other three options, namely the Great cardiac vein, Middle cardiac vein, and Small cardiac vein, are all tributaries of the coronary sinus. However, the Anterior cardiac vein is not a tributary of the coronary sinus. It drains directly into the right atrium instead.

The fibrous pericardium is innervated by the phrenic nerve. The phrenic nerve is responsible for providing sensory innervation to the fibrous pericardium, which is the tough outer layer of the pericardium. The phrenic nerve originates from the cervical spinal cord and travels down through the thorax to innervate the diaphragm and the fibrous pericardium. It plays a crucial role in transmitting sensory information from the pericardium to the brain, allowing for the perception of pain or other sensations in this area.

The moderator band is a muscular ridge that is present in the right ventricle of the heart. It extends from the interventricular septum to the base of the anterior papillary muscle. Its function is to help coordinate the contraction of the ventricles and facilitate the flow of blood during ventricular systole. The moderator band is not present in the other chambers of the heart, such as the right atrium, left atrium, or left ventricle. Therefore, the correct answer is right ventricle.

During phase 2 of the cardiac action potential, sodium channels open and calcium channels close. This phase is known as the plateau phase and occurs in ventricular muscle cells. The opening of sodium channels allows for the influx of sodium ions, which contributes to depolarization. At the same time, the closure of calcium channels prevents further calcium influx. The closure of potassium channels during this phase helps maintain the depolarized state. Therefore, the correct answer is 2, which indicates that systole occurs during phase 2 of the cardiac action potential.