Cardiovascular System - The Heart PPT

June 17, 2012 | By | Reply More

Cardiovascular System - The Heart PPT

PowerPoint lecture Slide

Download link below



Give a detailed description of the superficial and internal anatomy of the heart, including the pericardium, the myocardium, and the cardiac muscle.

Explain the functioning of the valves of the heart and how they relate to the heart sounds.

Discuss the conductive pathway of the heart, and relate that to clinical uses of the ECG.

Pulmonary & Systemic Circuits

Location of Heart within Thoracic Cavity

•Inside thoracic cavity
•In center of chest deep to sternum, apex tipped toward the left; base superior
•Inside mediastinum
•In pericardial space
Pericardium – Covering

1. Fibrous pericardium – tough, collagenous

2. Serous parietal pericardium (lines fibrous pericardium)

3. Pericardial space with 10-20 ml of  pericardial fluid

4. Serous visceral pericardium adheres to the heart surface  (also known as epicardium)

 Structure of Heart Wall

Epicardium = visceral Pericardium (serosa)
Myocardium: muscle tissue + c.t. + blood vessels + ?

Endocardium: simple squamous epithelium continuous

Cardiac Muscle

Striated, aerobic, interwoven,  autorhythmic
Intercalated discs – gap junctions, strong desmosomes
Functional syncytium
Fibrous Skeleton
Internal c.t. network with lots of collagen and elastic fibers

Encircles bases of great vessels

Encircles bases of valves


Isolate atria from ventricles elctrically

Reinforce myocardium itself

Surface Anatomy of Heart

Auricle of atria (expandable)
Coronary sulcus (between atria & ventricles)
Ant. & post. interventricular sulcus
Base (3rd costal cartilage) vs. apex (5th intercostal space)
Vessels entering & leaving the heart
Sectional (Internal) Heart Anatomy
Atria & ventricles
Interatrial & interventricular septae
Valves (fibrous tissue)
Pectinate muscles (auricles & ant. atria)
Trabeculae carneae (ventricles)
Chordae tendinae & papillary muscles
Left vs. Right Ventricle

Left: high pressure pump – Right: low pressure pump Þ right chamber is  thinner walled than left

Ventricles separated by interventricular septum

Structure and Function of Valves

4 sets of valves

Prevent backflow of blood

Close passively under blood pressure

Heart sounds produced by valve closure

Support for AV valves:

valves are restrained by chordae tendinae which are in turn attached to papillary muscles (prevention of backflow!)

Mitral Valve Prolapse

nMost common cardiac variation (5-10% of population)
nMitral valve cusps do not               close properly
nRegurgitation during left                ventricular systole

Not life threatening;                may be lifestyle threatening

How can you diagnose?

Blood flow pattern through the heart

1.Blood enters right atrium
2.Passes tricuspid valve into right ventricle
3.Leaves by passing pulmonary semilunar valves into pulmonary trunk and to the lungs to be oxygenated
4.Returns from the lung by way of pulmonary veins into the left atrium
5.From left atrium past bicuspid valve into left ventricle
6.Leaves left ventricle  past  aortic semilunar valves into  aorta
7.Distributed to  rest of the body

Cardiac Cycle

Actual physical contraction pattern of the myocardium as determined by the conduction.

A.Contraction is systole
B. Relaxation is diastole

The two atria are in systole and diastole together as are the two ventricles.


Auscultation of Heart Sounds:

1st HS: at beginning of ventricular contraction, due to?

2nd HS: at beginning of ventricular diastole, due to?

Coronary Circulation

Coronary arteries: first branches off the ascending aorta.


Myocardial Infarction (MI)

~ 1.3 Mio MIs / year in US
Most commonly due to severe CAD (coronary thrombosis)
Ischemic tissue degenerates → nonfunctional area = infarct
Predisposing factors?
Conducting System of the Heart

Specialized muscle cells (autorhythmic cells) conduct APs to time and synchronize the action of the chambers

SA node -pacemaker, spontaneously depolarizes most rapidly and initiate heart beat, positioned on back wall of right atrium , transmits action potential to

AV node – (where the four chambers meet).

AV bundle (bundle of His) transmits down top of interventricular septum where it divides into two

Bundle branches, one of which supplies each ventricle where they branch into

Purkinje fibers reflect up external walls of ventricles and  stimulate contraction of cardiac muscle cells as a unit.

Purkinje fibers extend into papillary muscles  as well


Cardiovascular System - The Heart PPT Download option

Tags: ,

Category: Medical

WARNING: Any unauthorised use or reproduction of content for commercial or any purposes is strictly prohibited and constitutes copyright infringement liable to legal action.