Heart GPT 2 Pt. 2

Question 1

How does the heart return to its original size and shape after contraction?

Answer 1

Elastic fibers in the heart’s connective tissue allow it to return to its original size and shape after contraction.

Question 2

What is the purpose of the cardiac skeleton?

Answer 2

The cardiac skeleton is a framework of dense connective tissue in the heart that provides structural support and electrical insulation between atria and ventricles.

Question 3

How are the heart’s electrical signals generated and distributed?

Answer 3

The heart’s electrical signals are generated by the sinoatrial (SA) node and distributed through the atria and ventricles, coordinating the heartbeat.

Question 4

What are autorhythmic cells, and where are they located in the heart?

Answer 4

Autorhythmic cells are specialized cardiac muscle cells capable of generating electrical impulses. They are located in the SA and AV nodes.

Question 5

What is the main pacemaker of the heart, and where is it found?

Answer 5

The SA node, found in the right atrium, serves as the heart’s primary pacemaker, initiating electrical impulses.

Question 6

Where is the atrioventricular (AV) node located, and what is its function?

Answer 6

The atrioventricular (AV) node is located in the heart, between the atria and ventricles. Its function is to delay the electrical signal from the atria, allowing the ventricles to fill with blood before they contract.

Question 7

What are conducting cells in the heart, and where are they located?

Answer 7

Pacemaker cells in the SA and AV nodes initiate electrical impulses, while contractile cells are responsible for the actual heart muscle contraction.

Question 8

How do pacemaker cells in the SA and AV nodes differ from contractile cells?

Answer 8

Pacemaker cells have automaticity and set the heart’s rhythm, while contractile cells do not spontaneously depolarize.

Question 9

Explain the pacemaker potential and its significance.

Answer 9

The pacemaker potential is a gradual depolarization of the pacemaker cells, setting the stage for an action potential and heart contraction.

Question 10

What is the role of the AV node in the heart’s electrical conduction?

Answer 10

The AV node ensures a slight delay in electrical conduction to allow the ventricles to fill with blood before contracting.

Question 11

Describe the function of conducting cells in the heart.

Answer 11

Conducting cells in the heart are responsible for transmitting electrical signals throughout the myocardium.

Question 12

What role do the internodal pathways play in the heart’s electrical conduction?

Answer 12

Internodal pathways distribute electrical impulses from the SA node to the AV node.

Question 13

Where are the Purkinje fibers located in the heart?

Answer 13

Purkinje fibers are specialized cardiac muscle fibers that rapidly transmit electrical impulses, coordinating ventricular contraction.

Question 14

How does the sequence of electrical stimulation lead to efficient ventricular contraction?

Answer 14

The sequence of electrical stimulation ensures a coordinated and efficient ventricular contraction, maintaining blood flow.

Question 15

What is an arrhythmia, and how can it affect heart function?

Answer 15

Arrhythmias are irregular heart rhythms that can disrupt normal cardiac function.

Question 16

What is an electrocardiogram (ECG), and how is it used in heart monitoring?

Answer 16

An electrocardiogram (ECG) is a graphical representation of the heart’s electrical activity, aiding in diagnosing arrhythmias and other cardiac conditions.

Question 17

What are the key components of an ECG, including the P wave, QRS complex, and T wave?

Answer 17

The P wave represents atrial depolarization, the QRS complex denotes ventricular depolarization, and the T wave corresponds to ventricular repolarization in an ECG.

Question 18

Explain the significance of the P-R interval and the Q-T interval in an ECG.

Answer 18

The P-R interval indicates the time it takes for the electrical impulse to travel from the atria to the ventricles, while the Q-T interval reflects ventricular depolarization and repolarization.

Question 19

What are the potential causes of valvular heart disease (VHD)?

Answer 19

Valvular heart disease (VHD) can result from congenital abnormalities, infections, or degenerative conditions affecting heart valves.

Question 20

How is blood supplied to the muscle tissue of the heart?

Answer 20

Coronary arteries supply oxygenated blood to the myocardium, allowing the heart to function.

Question 21

Describe the origin of coronary arteries and their role in coronary circulation.

Answer 21

The coronary arteries, including the left and right coronary arteries, branch from the aorta and provide vital blood supply to the heart muscle.

Question 22

What is the function of the great cardiac vein in coronary circulation?

Answer 22

The great cardiac vein is responsible for draining oxygen-depleted blood from the heart muscle (myocardium) and returning it to the right atrium of the heart in the coronary circulation.

Question 23

What is the role of the coronary sinus in collecting blood from the heart muscle?

Answer 23

The coronary sinus collects deoxygenated blood from the heart muscle and returns it to the right atrium of the heart.

Question 24

Explain the phases of the cardiac cycle, including systole and diastole.

Answer 24

The cardiac cycle consists of two main phases: systole and diastole. Systole is the contraction phase when the heart pumps blood into the arteries. Diastole is the relaxation phase when the heart fills with blood. These phases work together to maintain blood flow and circulation in the body.

Question 25

What is the primary function of the atrial systole phase in the cardiac cycle?

Answer 25

The primary function of the atrial systole phase in the cardiac cycle is to contract the atria, pushing blood into the ventricles to assist with ventricular filling before the subsequent ventricular systole phase.

Question 26

How do the phases of the cardiac cycle affect blood pressure?

Answer 26

The phases of the cardiac cycle, including systole (contraction) and diastole (relaxation), directly impact blood pressure. Systole increases blood pressure as the heart contracts and pumps blood into the arteries, while diastole decreases pressure as the heart relaxes and refills with blood.

Question 27

Describe the events during atrial contraction and ventricular systole in the cardiac cycle.

Answer 27

During atrial contraction, the atria contract to push blood into the ventricles, while during ventricular systole, the ventricles contract to pump blood into the pulmonary artery and aorta.

Question 28

What is isovolumetric ventricular contraction, and when does it occur?

Answer 28

Isovolumetric ventricular contraction is a phase of the cardiac cycle when the ventricles contract, increasing pressure inside them, but without any change in volume. This occurs at the beginning of systole, just after the closing of the atrioventricular valves and before the opening of the semilunar valves in the heart.

Question 29

How does the ventricular ejection phase differ from isovolumetric contraction?

Answer 29

The ventricular ejection phase involves the expulsion of blood from the ventricles into the arteries, while isovolumetric contraction is the phase when the ventricles contract without any change in volume.

Question 30

What triggers the closure of the semilunar valves in the heart?

Answer 30

The closure of the semilunar valves in the heart is triggered by the higher pressure in the arteries when the ventricles contract, preventing blood from flowing back into the ventricles.

Question 31

Explain the concept of isometric relaxation in the cardiac cycle.

Answer 31

Isometric relaxation in the cardiac cycle refers to the phase when the heart muscle relaxes without changing its overall length, allowing the ventricles to fill with blood before the next contraction.

Question 32

How do the AV valves open during the cardiac cycle, and what occurs during passive ventricular filling?

Answer 32

During the cardiac cycle, the AV valves (atrioventricular valves) open in response to increased atrial pressure as the atria contract. This allows blood to flow from the atria into the relaxed ventricles. Passive ventricular filling occurs when the ventricles expand and fill with blood from the atria, without active contraction.

Question 33

What are the key heart sounds, and when do they occur in the cardiac cycle?

Answer 33

The key heart sounds are “S1” (lub) and “S2” (dub). S1 occurs at the start of ventricular systole, while S2 occurs at the start of ventricular diastole.