Cardiovascular System Chapter 19

Questions and Answers

What is the pulmonary circuit?

The pulmonary circuit carries blood to the lungs for gas exchange and then returns it to the heart.

What is the systemic circuit?

The systemic circuit supplies blood to the organs and tissue in the body.

What is the difference between parietal pericardium and visceral pericardium?

The parietal pericardium is a tough superficial fibrous layer, while the visceral pericardium is a serous membrane covering the heart.

Describe the three parts of the heart wall: epicardium, endocardium, myocardium.

Epicardium is the serous membrane covering the heart; endocardium is the smooth inner lining; myocardium is composed of cardiac muscle. Signup and view all the answers

What are the functions of the fibrous skeleton of the heart?

It provides structural support, anchors cardiocytes, offers electrical insulation between atria and ventricles, and may aid in refilling the heart. Signup and view all the answers

Describe the left and right atria.

The left and right atria are the two superior chambers that receive blood returning to the heart. Signup and view all the answers

Describe the functions of the following valves: atrioventricular valve, tricuspid valve, mitral valve, semilunar valve, pulmonary valve, and aortic valve.

Atrioventricular valve regulates the opening between atria and ventricles; tricuspid valve has three cusps, prevents backflow; mitral valve has two cusps, prevents backflow. Signup and view all the answers

What is coronary circulation?

Coronary circulation is a system of blood vessels that serve the walls of the heart. Signup and view all the answers

What do the left and right coronary arteries do?

They deliver oxygenated blood to the heart. Signup and view all the answers

What is venous drainage?

Venous drainage is the route by which blood leaves an organ. Signup and view all the answers

What is the cardiac conduction system?

It coordinates the heartbeat and is composed of an internal pacemaker and nerve-like conduction through the myocardium. Signup and view all the answers

Describe the function of the following: SA node, AV node, bundle of His, and Purkinje fibers.

SA node initiates heartbeat; AV node acts as an electrical gateway; bundle of His transmits signals; Purkinje fibers spread signals through ventricles. Signup and view all the answers

What are slow calcium channels?

Slow calcium channels are voltage-gated channels that are permeable to calcium ions and slightly permeable to sodium ions. Signup and view all the answers

In an Electrocardiogram, what happens during the P wave, QRS complex, and T wave?

P wave: atrial depolarization; QRS complex: ventricular depolarization; T wave: ventricular repolarization. Signup and view all the answers

What is ventricular filling?

Ventricular filling occurs when AV valves open and blood flows into the ventricles, raising ventricular pressure. Signup and view all the answers

What is the end-diastolic volume?

End-diastolic volume is the amount of blood contained in one ventricle at the end of ventricular filling. Signup and view all the answers

What is isovolumetric contraction?

Isovolumetric contraction occurs when the ventricles depolarize and begin to contract while the atria are relaxed. Signup and view all the answers

What is ventricular ejection?

Ventricular ejection begins when ventricular pressure exceeds arterial pressure, forcing semilunar valves open. Signup and view all the answers

What is isovolumetric relaxation?

Isovolumetric relaxation is the early stage of ventricular diastole when the ventricles begin to expand. Signup and view all the answers

Define cardiac output.

Cardiac output is the total amount ejected by each ventricle in one minute and varies with activity level. Signup and view all the answers

Study Notes

Pulmonary and Systemic Circuits

The pulmonary circuit transports blood to the lungs for gas exchange and returns it to the heart.
The systemic circuit delivers oxygenated blood to the body's organs and tissues.

Pericardium Layers

Parietal pericardium: Tough fibrous layer providing structural support.
Visceral pericardium: Serous membrane that directly covers the heart.

Heart Wall Structure

Epicardium: Serous membrane covering the external surface of the heart.
Endocardium: Smooth inner lining of the heart and blood vessels.
Myocardium: Thick, muscular layer composed of cardiac muscle.

Fibrous Skeleton Functions

Provides structural support and anchors cardiocytes.
Offers electrical insulation between atria and ventricles.
May aid in heart refilling after each beat due to elastic recoil.

Atria Description

The left and right atria are the upper chambers of the heart that receive blood returning from the body and lungs, respectively.

Heart Valves Functions

Atrioventricular valves regulate blood flow between atria and ventricles.
Tricuspid valve: Three cusps, prevents backflow into the right atrium.
Mitral valve: Two cusps, prevents backflow into the left atrium.
Semilunar valves (pulmonary and aortic) prevent backflow from arteries into ventricles.

Coronary Circulation

A network of blood vessels that supply blood to the heart muscle itself.

Coronary Arteries

Right and left coronary arteries are responsible for delivering oxygenated blood to the heart tissue.

Venous Drainage

The pathway through which blood exits an organ, aiding in circulation.

Cardiac Conduction System

Coordinates the heartbeat through pacemaker activity and conduction pathways in the myocardium.

Key Components of the Conduction System

SA node: Pacemaker located in the right atrium that initiates heartbeats.
AV node: Acts as an electrical gateway to the ventricles, located in the interatrial septum.
Bundle of His: Conducts signals from the AV node to ventricles.
Purkinje fibers: Transmit signals throughout the ventricular myocardium.

Slow Calcium Channels

Voltage-gated channels that allow calcium ions to enter cells, playing a crucial role in cardiac muscle contraction.

Electrocardiogram (ECG) Waves

P wave: Indicates atrial depolarization triggered by the SA node.
QRS complex: Represents ventricular depolarization as the signal spreads through the myocardium.
T wave: Reflects ventricular repolarization before diastole.

Cardiac Cycle Events

Ventricular filling: Occurs when AV valves open, blood enters ventricles.
End-diastolic volume: Volume of blood in a ventricle at the end of filling.
Isovolumetric contraction: Ventricles contract with no volume change, atria relax.
Ventricular ejection: Blood is expelled when ventricular pressure exceeds arterial pressure.
Isovolumetric relaxation: Early diastole where ventricles expand following repolarization.

Cardiac Output

The total volume of blood ejected by each ventricle per minute, variable based on the body's demand and activity levels.

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Description

This quiz focuses on Chapter 19 of the cardiovascular system, specifically the pulmonary and systemic circuits. Test your knowledge about how blood circulates between the heart, lungs, and the rest of the body. Perfect for reinforcing key concepts from your studies.