THE HEART

GROUP 3

THE HEART

• Has the approximate size of a closed fist

• Mass ≈ 300 g

• It is connected to the great vessels

• Its walls are mainly muscle (myocardium)

•It lies free in the pericardium

POSITION OF THE HEART

FRONTAL VIEW

• Found in left side of the thorax, between the lungs

• Attached to the spinal column and diaphragm by ligaments

• Fluid between the pericardium and myocardium allows the heart to move freely when it beats

ANATOMY OF THE HEART

FRONTAL VIEW CORONAL SECTION THROUGH THE HEART

• There are four chambers in the heart:

-left atrium-left ventricle-right atrium -right ventricle

The right and left side are separated by the SEPTUM

RIGHT ATRIUM

LEFT ATRIUM

RIGHT VENTRICLE

LEFT VENTRICLE

VALVES

VENA CAVA PULMONARY VEIN

PULM

ON

ARY ARTERY

AORTA

Transverse section of the heart

Valve Position No. of cusps

Tricuspid Right atrium – right ventricle 3

Pulmonary Right ventricle – pulmonary artery 3

Mitral Left atrium – left ventricle 2

Aortic Left ventricle - aorta 3

Valves are connected to the heart muscle by chordae tendinae.

Their function is to ensure that blood flows in the correct direction only. This is controlled by the cusps (leaflets).

HEART NODES2 nodes:

•Sinoatrial node (heart’s natural pacemaker)

•Atrioventricular nodeImpulses sent from SAN to AVN which stimulates contraction of ventricles

Diagram showing position of nodes

AUSCILTATION OF VALVES

All four valves lie very close together under the sternum. Each valve is best heard over a distinct, well separated auscultation area over the chamber fed by the valve.

The Mitral valve is best heard in the mid-clavicular line of the fourth-fifth left intercostal space.

The tricuspid valve in the fifth intercostal space at the left sternal edge.

The aortic valve in the second intercostal space at the right sternal edge.

The pulmonary valve in the second intercostal space at the left sternal edge.

CARDIAC CYCLE• Atrial Systole• Isovolumetric Contraction• Rapid Ejection• Reduced Ejection• Isovolumetric Relaxation• Rapid Ventricular Filling• Diastasis

ATRIAL SYSTOLE• Prior to AS, blood has been flowing

from the atrium into the ventricle via the open AV valve.

• The atrium contracts and tops off the volume in the ventricle with only a small amount of blood.

• During atrium contraction, atrial pressure increases.

• Atrial pressure drops, when the atria stop contracting.

VOLUMETRIC CONTRACTION

• The AV valves close at the beginning of this phase, this is when pressure in the ventricles exceed the pressure in the atria.

• As the ventricles contract isovolumetrically the pressure inside increases, approaching the pressure in the aorta and pulmonary arteries

• Mechanically the isovolumic phase of ventricular systole is defined as the interval between the closing of the AV valves and opening of the SL valves.

RAPID EJECTION• Whilst the ventricles continue

contracting, the pressure inside them exceeds that of the aorta and pulmonary arteries.

• The SL valves open at the beginning of this phase of ventricular systole.

• Blood exits the ventricles, and the volume decreases rapidly as blood enters the arteries.

• Right ventricular contraction pushes the tricuspid valve into the atrium and increases atrial pressure.

REDUCED EJECTION• After the peak in ventricular and

arterial pressures, blood flows out of the ventricles decreases and ventricular volume decreases more slowly.

• When the ventricular pressure falls

below the pressure in the arteries, blood in the arteries begins to flow back toward the ventricles causing the SL valves to close.

• This marks the end of ventricular systole mechanically.

ISOVOLUMETRIC RELAXATION

• At the beginning of this phase the AV valves are closed.

• Throughout this and the previous two phases, the atrium in diastole has been filling with blood on top of the AV valve, causing atrial pressure to rise gradually.

• The pressure in the ventricles continues to drop.

• Ventricular volume is at a minimum and is ready to be filled again with blood.

RAPID VENTRICULAR FILLING

• Once the AV valves open, blood that has accumulated in the atria flows rapidly into the ventricles.

• Ventricular volume increases rapidly as blood flows as blood flows from the atria into the ventricles.

DIASTASIS

• Ventricular volume increases more slowly now. The ventricles continue to fill with blood until they are nearly full.

DISEASES

VALVE FAILURESTENOSIS

REGURGITATION

All valves can experience problems, however MITRAL and AORTIC valves are most common valves to experience problems.Narrowing- the heart pumps blood harder to pass the narrowingLeaking- the heart pumps harder to pass blood leaking back

CAUSES

DegenerationCongenital Heart DiseaseRheumatic Heart Disease

Calcification

Valve Infection (Endocarditis)Floppy Valve

Aortic/Heart EnlargementComplication of Other Diseases

Others

SYMPTOMSShortness of Breath

TirednessPalpitations

Tissue SwellingChest Pain

Others

DIAGNOSISEchocardiography

Cardiac Catheterisation

TREATMENT

Mild Condition: No Treatment Needed

Medication: Diuretics, Warfarin, ACE-I, ARAs

Surgery: Stretch, Repair, Replace the Valves

Endocarditis: Antibiotics

Putting chin to knee, June 5, 2011 by fmindlin 0 , http://fmindlin.wordpress.com/2011/06/05/heartofdarknessliveroftwilight/

Leonardo da Vinci Anatomy Drawinghttp://www.leonardo-da-vinci-biography.com/leonardo-da-vinci-anatomy.html

William Harvey, Valued treasures, http://historical.hsl.virginia.edu/treasures/harvey.html

In Vivo 3-Dimensional Flow Connectivity Mapping After Extracardiac Total Cavopulmonary Connection, Copyright © 2011 by American Heart Association, Inc. All rights reserved. Unauthorized use prohibited., http://circ.ahajournals.org/content/118/2/e16/F2.expansion

3D CT of Heart, Science Photo library, http://www.sciencephoto.com/media/111675/enlarge

Maryland Heart Center, About the Heart, Http://www.umm.edu/heart/anatomy.htm

• References1. http://www.youtube.com/watch?v=H04d3rJC

LCE accessed 16/10/2011

2. http://www.fallingpixel.com/heart-anatomy--3d-model/31372

3. http://www.yale.edu/imaging/echo_atlas/references/heart_anatomy.html

4. http://www.mydr.com.au/heart-stroke/animation-how-your-heart-pumps

5. http://franciscan.adam.com/content.aspx?productId=13&pid=13&gid=100161

6. http://biology.about.com/od/anatomy/ss/heart-nodes.htm

• British Heart Foundation and Help for the Heroes, http://www.longlevenschiro.com/2010/09/charities/

• Heart Valves and Valve Disease, http://www.patient.co.uk/health/Heart-Valves-and-Valve-Disease.htm

• Dr Patrick Davey, Heart valve disease, Net Doctor, http://www.netdoctor.co.uk/diseases/facts/heartvalvedisease.htm

• Cardiac Services, http://www.kaweahdelta.org/services/cardiac.asp