Anatomy of the Heart Flashcards

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Questions and Answers

How big is the heart?

Approximately the size of a fist

How much does the heart weigh?

Varies with body height and weight; it averages approximately 250 to 300g in females and 300-350g in males.

Where is the position of the heart within the body?

It is found in the mediastinum and 2/3 of it lies left of the midline with 1/3 on the right.

What forms the apex of the heart?

The left ventricle Signup and view all the answers

The base of the heart is directed where?

Toward the right shoulder Signup and view all the answers

Where does the heart apex point to?

The left hip Signup and view all the answers

What forms the base of the heart?

The base is the posterior aspect of the heart formed largely by the left atrium and a narrow portion of the right atrium. Signup and view all the answers

How many surfaces does the heart have?

3 Surfaces Signup and view all the answers

What are the surfaces of the heart?

Sternocostal/Anterior, Diaphragmatic/inferior, Base/Posterior. Signup and view all the answers

What forms the sternocostal surface of the heart?

Mainly the right ventricle, right atrium and left ventricle. Signup and view all the answers

What forms the diaphragmatic surface of the heart?

Mainly 2/3rds of the left ventricle, 1/3rd of the right ventricle. Signup and view all the answers

What forms the base surface of the heart?

Almost all of the left atrium. Signup and view all the answers

How many borders of the heart are there?

There are 4 borders of the heart. Signup and view all the answers

What are the borders of the heart?

Right, Inferior, Left, Superior. Signup and view all the answers

What forms the right border of the heart?

Right atrium Signup and view all the answers

What forms the inferior border of the heart?

Right ventricle, Apex by left ventricle. Signup and view all the answers

What forms the left border of the heart?

Left ventricle, top by left auricle. Signup and view all the answers

What forms the superior border of the heart?

2 Auricles, pulmonary trunk. Signup and view all the answers

Auricles are found at the ____ only.

Atria Signup and view all the answers

The coronary sulcus marks the border between what?

Between atria and ventricles. Signup and view all the answers

What do the two interventricular sulci mark?

Border between the two ventricles. Signup and view all the answers

The sulci are filled with ____.

fat and vessels Signup and view all the answers

What is the pericardium?

A double-walled fibrous serous sac around the heart. Signup and view all the answers

The pericardium is composed of how many layers?

3 layers Signup and view all the answers

What are the layers of the pericardium?

A superficial fibrous pericardium, A deep two-layer serous pericardium. Signup and view all the answers

What are the characteristics of the fibrous pericardium?

Tough, collagenous and indistensible. Signup and view all the answers

What are the two serous pericardium layers?

The Parietal layer, The Visceral layer. Signup and view all the answers

What does the parietal pericardium layer line?

The internal surface of the fibrous pericardium. Signup and view all the answers

What does the visceral pericardium layer a.k.a epicardium line?

The surface of the heart. Signup and view all the answers

The fibrous pericardium firmly blends (attaches) with what?

Adventitia of aorta, pulmonary trunk, superior vena cava (not IVC), central tendon of diaphragm and sternum (sternopericardial ligaments). Signup and view all the answers

Where do the two serous pericardium layers become continuous?

At the roots of the great vessels. Signup and view all the answers

What separates the two serous pericardium layers?

A pericardial cavity with a small amount (10-20ml) of pericardial fluid. Signup and view all the answers

What are the functions of the pericardium?

Protects and anchors the heart, Prevents overfilling of the heart with blood, Allows for the heart to work in a relatively friction-free environment. Signup and view all the answers

What is the blood supply of the pericardium?

Pericardiocophrenic branch of internal artery/veins. Signup and view all the answers

What is the nerve supply of the pericardium?

<ol> <li>The somatic innervation (sharp pain) of fibrous pericardium & parietal serous layers is by phrenic and intercostal nerves; 2. The insensitive/visceral (dull pain) innervation of the visceral serous layer is by (autonomic) superficial and deep cardiac plexuses.</li> </ol> Signup and view all the answers

What happens during cardiac tamponade?

Fluid in the pericardial sac limits movement of the heart and thus, compromises cardiac output. Signup and view all the answers

What are pericardial sinuses?

These are blind pouches formed by the reflection of the parietal pericardium to the visceral pericardium around the great vessels. Signup and view all the answers

What are the two pericardial sinuses?

<ol> <li>Oblique sinus of the pericardium; 2. Transverse sinus of the pericardium.</li> </ol> Signup and view all the answers

Where is the oblique sinus of the pericardium located?

Dorsal to the left atrium at the base of the heart. Signup and view all the answers

How is the oblique sinus of the pericardium formed?

By pericardial reflections surrounding the inferior vena cava and four pulmonary veins. Signup and view all the answers

Where is the transverse sinus of pericardium located?

Between the atria and the great vessels. The pulmonary trunk and ascending aorta in front, superior vena cava behind, pulmonary veins and left atrium below. Signup and view all the answers

Why is the transverse sinus of the pericardium important to cardiac surgeons?

A temporary ligature is passed through this sinus during some lung and cardiac operations. Signup and view all the answers

What are the three layers of the heart?

<ol> <li>Epicardium (outer, visceral layer of serous pericardium); 2. Myocardium: cardiac muscle; 3. Endocardium (inner): Thin layer of endothelium lining chambers of heart and valves.</li> </ol> Signup and view all the answers

How many openings does the right atrium have?

It has 6 openings. Signup and view all the answers

What are the openings of the right atrium?

<ol> <li>SVC; 2. IVC; 3. Coronary sinus; 4. Tricuspid orifice; 5. Anterior cardiac vein; 6. Venae cordis minimae (Thebesian veins).</li> </ol> Signup and view all the answers

What are the features of the right atrium?

<ol> <li>Larger and thinner wall than left atrium; 2. Auricle (ear); contains pectinate muscles; 3. Rough anterior wall; contains pectinate muscles; 4. Smooth posterior wall/sinus venarum; 5. Sulcus terminalis (externally) and crista terminalis (internally) between the 2 parts.</li> </ol> Signup and view all the answers

What are pectinate muscles like?

Comb-like horizontal parallel ridges. Signup and view all the answers

What vessels does the smooth posterior wall receive?

SVC, IVC, coronary sinus & anterior cardiac veins. Signup and view all the answers

What are the internal features of the right atrium?

<ol> <li>Fossa ovalis; 2. Limbus fossa ovalis; 3. SA node; 4. AV node.</li> </ol> Signup and view all the answers

What is the fossa ovalis?

An oval, thumbprint-sized depression in the interatrial septum (remnant of foramen ovale in fetus). Signup and view all the answers

What is the limbus fossa ovalis?

The ridge around the fossa ovalis. Signup and view all the answers

Where is the SA node located?

In the superior end of sulcus terminalis, at the junction between right atrium & SVC. Signup and view all the answers

Where is the AV node located?

In the lower part of the interatrial septum, above attachment of septal cusp of tricuspid valve and to the left of opening of coronary sinus. Signup and view all the answers

What are the general features of the right ventricle?

<ol> <li>Crescent-shaped on transverse section; 2. Smooth part: infundibulum/conus arteriosus; 3. Rough part: Projecting ridges called trabeculae carneae; 4. Supraventricular crest demarcation between the smooth & rough part/inflow & outflow tract.</li> </ol> Signup and view all the answers

Describe the course that the blood takes in the right ventricle.

The blood takes a U-shaped course from the orifice of entrance to the orifice of exit. Signup and view all the answers

What are the features of the right ventricle?

<ol> <li>Cordae tendinae; 2. Papillary muscles; 3. Moderator band/septomarginal trabecula; 4. AV valve (tricuspid valve); 5. Pulmonary valves.</li> </ol> Signup and view all the answers

Where is the cordae tendinae located?

It extends from the free edges of tricuspid valve to the apices of papillary muscle. Signup and view all the answers

What do the cordae tendinae look like?

Strands are like the cords of a parachute. Signup and view all the answers

What is the function of the cordae tendinae?

Prevents eversion of tricuspid valves into the right atrium and regurgitation of ventricular blood into atrium during systole. Signup and view all the answers

Papillary muscles are divided into 3. What are they?

Anterior, posterior and septal. Signup and view all the answers

What are the papillary muscles?

Conical muscular projections from the ventricular wall and are attached to cordae tendinae. Signup and view all the answers

What is the function of the papillary muscles?

Helps prevent valve prolapse and regurgitation of blood (Note: The chordae tendinae and papillary muscles do not 'pull' the valves open). Signup and view all the answers

Describe the three papillary muscles.

<ol> <li>Posterior - large and connected to anterior and posterior cusps; 2. Anterior - small and connected to posterior and septal cusps; 3. Septal - connected to anterior and septal cusps.</li> </ol> Signup and view all the answers

What is the moderator band?

A muscular bundle extending from the inferior part of the IV septum to the base of the anterior papillary muscle. Signup and view all the answers

What is the function of the moderator band?

It carries part of the right bundle of the AV bundle. It separates the ridged muscular wall of the inflow part of the chamber from the smooth wall of the conus arteriosus (outflow part). Signup and view all the answers

What are the cusps of the tricuspid valve?

Anterior, posterior and septal cusps. (admits 3 fingers) Signup and view all the answers

Where is the pulmonary valve located?

At the location between the infundibulum/conus arteriosus and the pulmonary trunk. Signup and view all the answers

What is the function of semilunar cusps?

Prevent regurgitation of blood from pulmonary trunk during diastole. Signup and view all the answers

At which surface is the left atrium located?

At the base of the heart (posterior surface). Signup and view all the answers

In left atrium, Windsock-like left auricle forms the ___ part of the left border.

superior Signup and view all the answers

Left atrium has a slightly thicker wall than right atrium.

True (A) Signup and view all the answers

What are the features of the left atrium?

<ol> <li>Large smooth-walled part; 2. Rough part (left auricle has musculi pectinati/small pectinate muscle); 3. Interatrial septum which slopes posteriorly and to the right; 4. Left AV (mitral) valves.</li> </ol> Signup and view all the answers

What is the function of the smooth-walled part of the left atrium?

Site of emptying of the four large valveless pulmonary veins on the posterior wall. Signup and view all the answers

What is found on the interatrial wall of the left atrium?

An oval thin area which is the fossa ovalis. Superior edge of septum primum is found. Signup and view all the answers

The Mitral valve opens to ___

left ventricle Signup and view all the answers

Mitral valve looks like ___

a miter, the headdress worn by bishops. Signup and view all the answers

What are the features of the left ventricle?

<ol> <li>Thicker wall than the right ventricle; 2. The aortic vestibule/smooth-walled part; 3. Rough part/Trabeculae carneae; 4. Inflow and outflow tracts are separated by the anterior mitral leaflet (anterior cusps) V shape; 5. Two papillary muscles; 6. AV valve (Bicuspid); 7. Aortic valve; 8. Behind each cusp, aortic wall bulges to form an aortic sinus.</li> </ol> Signup and view all the answers

Smooth-walled part of LV is the _____

superior portion (outflow path) Signup and view all the answers

What is the difference between trabeculae carneae in left ventricle with those in the right ventricle?

Finer and more numerous. Signup and view all the answers

What are the two papillary muscles in the left ventricle?

Anterior and posterior. Signup and view all the answers

What is the function of the mitral valve?

Guards the AV orifice. Signup and view all the answers

In bicuspid valve, anterior cusp is ___ than the posterior cusp (size).

larger Signup and view all the answers

What is the function of the aortic valve?

Guards the aortic orifice. Signup and view all the answers

How many cusps does the aortic valve have?

3 cusps. Right cusp on anterior wall and left + posterior cusps are situated on the posterior wall. Signup and view all the answers

What are the 2 parts of the interventricular septum?

<ol> <li>Membranous part (superior); 2. Muscular part (inferior).</li> </ol> Signup and view all the answers

Explain a little on the interventricular septum.

<ul> <li>Bulges (convex) to right; - Lies vertically & in coronal plane; - Attaches to AV rings; - As thick as left ventricular wall.</li> </ul> Signup and view all the answers

How many sets of valves does the heart have?

4 sets of valves. Signup and view all the answers

What are the valves between the atria and the ventricles called?

Atrioventricular valves. Signup and view all the answers

What are the valves between the ventricles and arterial trunks called?

Semilunar valves. Signup and view all the answers

How are AV and semilunar valves closed?

By pressure. They are NOT closed by muscular contraction applied to the cusps. Signup and view all the answers

Atrioventricular valves close during whereas semilunar valves close during .

systole, diastole. Signup and view all the answers

Closing of AV valves produces ____ sound.

Lub. Signup and view all the answers

Closing of semilunar valves produces ___ sound.

Dub. Signup and view all the answers

Compare right & left ventricle in terms of shape in cross section.

Right ventricle - Crescentic, Left ventricle - Circular. Signup and view all the answers

What is the blood flow course in the left ventricle?

V-shape course. Signup and view all the answers

Study Notes

Size and Weight of the Heart

Heart is approximately the size of a fist.
Weighs around 250-300 grams in females and 300-350 grams in males, varying with body size.

Position and Orientation

Located in the mediastinum, with 2/3 on the left and 1/3 on the right.
Apex points towards the left hip; base directed toward the right shoulder.

Structure of the Heart

Three main surfaces:
- Sternocostal/Anterior: Comprised mainly of the right ventricle, right atrium, and left ventricle.
- Diaphragmatic/Inferior: 2/3 comprised of the left ventricle and 1/3 of the right ventricle.
- Base/Posterior: Mainly formed by the left atrium.
Four borders:
- Right border formed by the right atrium.
- Inferior border formed by the right ventricle and apex by the left ventricle.
- Left border formed by the left ventricle and left auricle.
- Superior border formed by the two auricles and pulmonary trunk.

Pericardium

A double-walled fibrous sac encasing the heart with three layers:
- Superficial fibrous pericardium.
- Deep serous pericardium with parietal and visceral layers.
Functions include protecting and anchoring the heart, preventing overfilling, and providing a friction-free environment.

Sinuses and Cavities

Pericardial sinuses are blind pouches formed by the reflection of the parietal pericardium: oblique and transverse sinuses.
Transverse sinus is critical for cardiac surgeries.
Pericardial cavity contains 10-20ml of pericardial fluid separating the serous layers.

Heart Wall Layers

Three layers of the heart:
- Epicardium: outer layer, also the visceral layer of the serous pericardium.
- Myocardium: muscular middle layer.
- Endocardium: inner endothelial lining of heart chambers and valves.

Right Atrium

Contains six openings: SVC, IVC, coronary sinus, tricuspid orifice, anterior cardiac vein, and Thebesian veins.
Features include larger, thinner walls compared to the left atrium, various muscle types, and internal structures like the fossa ovalis and nodes (SA and AV).

Right Ventricle

Crescent-shaped with a U-shaped blood flow path.
Features include cordae tendinae, papillary muscles (anterior, posterior, septal), and the moderator band.
Functions of the papillary muscles and cordae tendinae include preventing valve prolapse and regurgitation.

Left Atrium

Located at the posterior surface of the heart and has a slightly thicker wall than the right atrium.
Features include large smooth wall for pulmonary veins, rough auricular walls, and the mitral valve leading into the left ventricle.

Left Ventricle

Thicker walled than the right ventricle with a V-shaped blood flow path.
Contains aortic vestibule, mitral valve, and two papillary muscles (anterior, posterior).
Functions of the mitral valve include guarding the AV orifice and preventing backflow.

Valves of the Heart

Four sets of valves:
- Atrioventricular valves (AV) between atria and ventricles.
- Semilunar valves between ventricles and arterial trunks.
AV valves close during systole, while semilunar valves close during diastole, producing heart sounds: "Lub" for AV closure and "Dub" for semilunar closure.

Interventricular Septum

Comprised of a membranous part (superior) and a muscular part (inferior).
Lies vertically and bulges toward the right, providing structural integrity to the heart.

Shape Variations

Cross-sectional shapes differ: right ventricle is crescentic, while left ventricle is circular.

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Description

This quiz focuses on essential facts about the anatomy of the heart. Learn about its size, weight, and position within the body through flashcards designed for quick study and retention. Perfect for students in health sciences or anyone keen to understand cardiac anatomy.