CARDIAC MUSCLES Presented by: Tagreed AL-turki

Contents: different type of muscles Heart structure The wall of the heart Cardiac muscle cell structure Intercalated disk valves of the heart The Fibrous Skeleton of the Heart The conducting system of the heart Heart disease

INTRODUCTION There is different type of muscles skeletal muscles cardiac muscles Smooth muscles

cardiac muscles The heart is formed of : Tow thin atria. Tow thick ventricles.

The wall of the heart is formed of 3 layer:

Wall of the heart under E.M

Characteristic of cardiac muscle fibres Individual muscle cells joined together by cell junction and Covered by sarcoplasma Cytoplasm: it is granular by glycogen, mitochondria, lipochrome granules.

E.M Picture of the Cardiac Muscle Fibres

There are three types of junctional complex at intercalatediscs Desmosmal junction: prevent separation of the muscle cell during cardiac contracton. Adherens junction GAP junction: impulses spread over the heart from one cell to another.

Autonomic nervous system Cardiac muscles are mesodermal in origin but they are innervated. Cardiac muscles Can not divide or regenerate after injury.

Valves of the heart Simple squamous endothelium C.T Collagenous fibres Elastic fibres

The Fibrous Skeleton of the Heart

The conducting system of the heart (Vascular neuro-muscular structure) Each part of of the conducting system is formed of: Nerve fibres or nerve cell between these cells. They are supported by collagenous and elastic fibres. The moderator band.

The moderator band formed of.. Fat cell. Blood capillaries. Purkinje muscle fibres. Nerve fibres.

Purkinje muscle fibres position and function Transmitting the cardiac contract 5times faster than the cardiac muscle fibres

characteristic of Purkinje fibers Short. Thick. Paler than the cardiac fibres.

Cross section of Purkinje fibers Enclosed by irregular sarcolemma. Rich in nerve cell.

Heart disease Coronary heart disease Ischaemic heart disease Pulmonary heart diseasePulmonary heart disease :a failure of the right side of the heart.

Coronary heart disease Artery disease (CAD) Atherosclerotic heart diseasetherosclerotic Disease develops when a combination of fatty material, calcium, and scar tissue (plaque) builds up in the arteries If plaque completely blocks blood flow; it may cause a (heart attack) myocardial infarction) (sudden cardiac)

Ischaemic heart disease Ischaemic heart disease is a disease characterized by reduced blood supply to the heart.diseaseheart Most ischaemic heart disease is caused by atherosclerosis, usually present even when the artery lumens appear normal atherosclerosisartery lumens

Pulmonary heart disease Valve stenosis means the narrowing of a valve. Pulmonary stenosis is a narrowing of the valve that lets blood flow from the lower-right chamber (the right ventricle) into the lungs.