Divided attention
Classified in Biology
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Heart:is a hollow,muscular organ,It consist of:
Endocardium:a layer of epithelial tissuethat lines
the inside of the heart.It continue from the
endothelium that lines the blood vessels.
Myocardium:middle layer is the thickest part of
the heart.It is formed of cardiac muscle tissue.
themuscle fibres are long,striated and branched.
myocardial contractions are involuntary,fast and
powerful.Pericardium:double membrane
surrounding the heart.The space between the two
membranes is called the pericardial space.
Structure of heart:Chambers :heart is divided in
four parts.Two uppers chambers(atria) and two
lower(ventricles).Atria:thin walls blood flows
from veins.Ventricles:thickest walls left ventricle
thicker than right,blood leave heart and flow into
arteries.The hear is separated by interventrcular
septum.Valves:atria and ventricles connected by
atrioventricular valves.Right(tricuspid valve)
Left(mitral valve).Semilunar valve preven the
blood flowing backwards into ventricles.