Anatomy and Physiology Chapter 18 Flashcards

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Questions and Answers

What are the layers of the heart wall?

epicardium

endocardium

epicardium, myocardium, endocardium (correct)

myocardium

What is the visceral layer of the serous pericardium called?

epicardium

What forms the bulk of the heart?

myocardium

The endocardium is a thick layer of connective tissue in the heart.

False Signup and view all the answers

Identify the groove between the left atria and left ventricle.

left atrioventricular groove Signup and view all the answers

Identify the groove between the right atria and right ventricle.

right atrioventricular groove Signup and view all the answers

What separates the ventricles in the front?

anterior interventricular sulcus Signup and view all the answers

What term refers to the internal partition of the ventricles?

interventricular septum Signup and view all the answers

What do the right atria have that brings blood to it?

superior vena cava, inferior vena cava, coronary sinus Signup and view all the answers

What do the left atria receive?

left and right pulmonary veins Signup and view all the answers

What are the functions of the atria?

receiving chambers Signup and view all the answers

What does the left ventricle do?

pumps oxygenated blood to the body Signup and view all the answers

What is the function of the right ventricle?

pumps deoxygenated blood to the lungs Signup and view all the answers

What do the ventricles do?

pump blood Signup and view all the answers

What returns blood from body regions superior to the diaphragm?

superior vena cava Signup and view all the answers

What is the role of the inferior vena cava?

returns blood from the body regions inferior to the diaphragm Signup and view all the answers

What collects blood draining from the myocardium?

coronary sinus Signup and view all the answers

What do the left pulmonary veins do?

transport blood to the heart from the left lung Signup and view all the answers

What do the right pulmonary veins do?

transport blood to the heart from the right lung Signup and view all the answers

What does the right pulmonary artery do?

carries blood to the right lung Signup and view all the answers

What does the left pulmonary artery do?

carries blood to the left lung Signup and view all the answers

What does the pulmonary trunk do?

routes blood into left/right pulmonary artery Signup and view all the answers

What does the aorta do?

carries blood from the heart to body tissues Signup and view all the answers

What are atrioventricular valves?

prevent backflow into atria when the ventricles contract Signup and view all the answers

The atrioventricular valve consists of two cusps and is known as the tricuspid valve.

False Signup and view all the answers

What happens when atrial pressure is greater than ventricular pressure?

valve opens Signup and view all the answers

What happens when ventricular pressure is greater than atrial pressure?

valve closes Signup and view all the answers

What is coronary circulation?

functional blood supply of the heart Signup and view all the answers

What is the anterior interventricular artery?

subsection of the left coronary artery Signup and view all the answers

What does the circumflex artery supply?

supplies left atrium and posterior walls of the left ventricle Signup and view all the answers

What does the right marginal artery serve?

myocardium of the lateral right side of the heart Signup and view all the answers

What does the posterior interventricular artery supply?

supplies the posterior ventricular walls Signup and view all the answers

Where do cardiac veins follow?

path of coronary arteries Signup and view all the answers

What is the great cardiac vein?

tributary of sinus in the anterior interventricular sulcus Signup and view all the answers

What does the small cardiac vein run along?

heart's right inferior margin Signup and view all the answers

Where do anterior cardiac veins empty?

directly into the right atrium Signup and view all the answers

Where is the middle cardiac vein located?

in posterior interventricular sulcus Signup and view all the answers

What is the intrinsic conduction system?

the intrinsic ability for cardiac muscle to depolarize and contract Signup and view all the answers

What is the SA node?

the pacemaker of the intrinsic conduction system Signup and view all the answers

What is the function of the AV node?

delays impulse, allows atria to contract fully Signup and view all the answers

What is the AV bundle?

only electrical connection between atria and ventricles Signup and view all the answers

What are bundle branches?

conduct impulses through interventricular system Signup and view all the answers

What do Purkinje fibers do?

cause ventricles to contract Signup and view all the answers

What is the cardiac cycle?

all events associated with one heartbeat Signup and view all the answers

What is systole?

period of contraction Signup and view all the answers

What is diastole?

period of relaxation Signup and view all the answers

What is the P-R interval?

part of ECG from beginning of atrial excitation to beginning of ventricular excitation Signup and view all the answers

What is the S-T interval?

part of ECG where the entire ventricular myocardium is depolarized Signup and view all the answers

What does the Q-T interval represent?

part of ECG reflecting ventricular depolarization through repolarization Signup and view all the answers

What are the three main phases of the cardiac cycle?

All of the above Signup and view all the answers

What occurs during passive filling of the ventricles?

Atrial pressure > ventricular pressure Signup and view all the answers

What follows atrial contraction in the cardiac cycle?

Ventricular Contraction Signup and view all the answers

What is the end diastolic volume (EDV)?

maximum volume of blood ventricles contain during diastole Signup and view all the answers

What is the end systolic volume (ESV)?

volume of blood in a ventricle at the end of contraction Signup and view all the answers

Study Notes

Heart Wall Layers

Comprises three layers: epicardium, myocardium, endocardium.

Epicardium

The outermost layer; known as the visceral layer of the serous pericardium.

Myocardium

The thickest layer forming the heart's bulk, made of cardiac muscle tissue.
Atria cells contract together; ventricles cells also contract in unison.

Endocardium

Composed of a smooth layer of endothelium and a thin connective tissue layer.
Direct contact with blood and helps reduce friction during heartbeats.

Atrioventricular Grooves

Left atrioventricular groove: the depression between the left atrium and left ventricle.
Right atrioventricular groove: the depression between the right atrium and right ventricle.

Interventricular Sulci

Anterior interventricular sulcus: separates ventricles at the front.
Posterior interventricular sulcus: separates ventricles at the back.

Septa

Interventricular septum: partitions the two ventricles internally.
Interatrial septum: divides the atria.

Atria

Right atrium: receives blood from the superior/inferior vena cava and coronary sinus.
Left atrium: receives oxygenated blood via left and right pulmonary veins.
Functions: receiving chambers for deoxygenated (right atrium) and oxygenated blood (left atrium).

Ventricles

Left ventricle: pumps oxygenated blood to the body through the aorta.
Right ventricle: pumps deoxygenated blood to the lungs via pulmonary trunk/arteries.

Great Vessels

Superior vena cava: returns blood from above diaphragm to the right atrium.
Inferior vena cava: returns blood from below diaphragm to the right atrium.
Coronary sinus: collects blood draining from the heart muscle, entering the right atrium.
Pulmonary veins (left and right): transport oxygenated blood from the lungs to the left atrium.
Pulmonary trunk: branches into left and right pulmonary arteries for blood to the lungs.
Aorta: carries oxygenated blood from the heart to the body tissues.

Valves

Atrioventricular valves prevent backflow into the atria when ventricles contract; includes bicuspid (left) and tricuspid (right) valves.
Chordae tendineae connect to papillary muscles; when ventricles contract, these muscles tighten to close valves.

Pressure Dynamics

Open condition: atrial pressure is greater than ventricular pressure.
Closed condition: ventricular pressure is greater than atrial pressure.

Coronary Circulation

Functional blood supply to the heart; shortest circulation in the body.
Includes arteries such as anterior interventricular and circumflex arteries, and veins like great cardiac vein.

Intrinsic Conduction System

Autonomous depolarization and contraction due to gap junctions, ensuring coordinated heart rhythm.

Key Components of Conduction

Sinoatrial (SA) node: the heart's pacemaker.
Atrioventricular (AV) node: delays impulse for complete atrial contraction.
AV bundle: the only electrical link between atria and ventricles.
Bundle branches: conduct impulses throughout the ventricular myocardium.
Purkinje fibers: trigger contraction of ventricular muscle cells.

Cardiac Cycle

Represents all events in one heartbeat, consisting of systole (contraction) and diastole (relaxation).
Main phases include ventricular filling, ventricular contraction, and isovolumetric relaxation.

Ventricular Filling Phases

Passive filling occurs as atrial pressure exceeds ventricular pressure, opening AV valves for blood flow.
Atrial contraction adds an extra 20% of blood into the ventricles.

Ventricular Contraction Phases

Isovolumetric contraction follows ventricular depolarization, where AV valves close.
Ventricular ejection occurs when ventricular pressure surpasses arterial pressure, opening semilunar valves.

Blood Volume Terms

End Diastolic Volume (EDV): maximum blood volume in the ventricle at the end of diastole.
End Systolic Volume (ESV): blood volume in the ventricle at the end of systolic contraction.

ECG Intervals

P-R interval: duration from atrial to ventricular excitation.
S-T interval: period of plateau phase in ventricular depolarization.
Q-T interval: duration of ventricular depolarization and repolarization.

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Description

Study the layers of the heart wall with these flashcards focusing on the epicardium, myocardium, and endocardium. Perfect for understanding the structure and function of the heart in your anatomy and physiology course.