12.09.2011

RIGHT ATRIUM

Posted on 8:12 PM by know about heart


It is the right upper chamber of the heart, which is quadrilateral shape. It receives venous blood by superior and inferior venacava from the whole body; it forms some border and surface of heart such as right border, part of upper border, part of sternocostal surface. It also forms one third of the base of the heart.
FEATURE OF THE RIGHT ATRIUM:
Right auricle: - It is a hollow conical muscular projection. It covers the root of the ascending aorta.
Sulcus terminalis: A shallow groove that runs alone the right border of the right atrium is called Sulcus terminalis .The SA node or pacemaker of the heart is situated here.
Right atrium receives superior venacava at the upper end and inferior venacava at the lower end. Right atrioventricular groove is situated between right atrium and right ventricle. Right atrioventricular groove separates atrium from ventricle.
Interior of right atrium: It is divided into two parts. Smooth part known as sinus venarum is lies posteriorly and rough part or atrium proper lies anteriorly. This two part is sepanated by crista terminalis.
A. Smooth part: Sturctures open into this part is-
1) Superior venacava-guarded by no valve. This opening lies in the superior and posterior part of the right atrium.
2) Inferior venacava: This opening is guarded by eustachian valve. It lies in the inferior and posterior part of the right atrium.
3)  Coronary sinus-It is guarded by thebesian valve.
4) Anterior cardiac vein.
5) Venacordis minimi.
6) Right marginal vein.

B. Rough part: It presents following feature:
1) Crista terminalis: It is a smooth  muscular ridge which separates rough part from smooth part.
2) Musculi pectinati: A parallel muscular ridge extends from crista terminalis and reaches into right auricle. IN auricle musculi pectinati form trabeculations.
 3) Septal wall that present-
a) Foramen ovale
 b) limbus of fossa ovalis
 c) Triangle of Koch
 d) Torus aorticus
 4) Vestible of tricuspid valve.
 Development:
Smooth part: Smooth part develops from absorption of right horn of sinus venosus
Rough part :Rough part develops from right part of primitive atrium.

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