SSM Heart - Aina Aqilah

BM21110064
SSM Assignment
Heart Chambers
The right atrium receives the superior vena cava in its upper and posterior part, the inferior
vena cava and coronary sinus in its lower part, and the anterior cardiac vein (draining much of
the front of the heart) anteriorly. Running more or less vertically downwards between the venae
cavae is a distinct ridge, the crista terminalis (indicated on the outer surface of the atrium by a
shallow groove the sulcus terminalis). This ridge separates the smooth walled posterior part of
the atrium, derived from the sinus venosus, from the rough-walled anterior portion, which is
prolonged into the auricular appendage and which is derived from the fetal atrium. The
openings of the inferior vena cava and the coronary sinus are guarded by rudimentary valves;
that of the inferior vena cava being continuous with the annulus ovalis around the shallow
depression on the atrial septum, the fossa ovalis, which marks the site of the fetal foramen
ovale.
The pulmonary valve admits three fingers and bears three flaplike cusps (medial, anterior and
inferior) These are attached by their base to the fibrous ring of the tricuspid orifice. A muscular
ridge, the infundibular ventricular crest, lies between the atrioventricular and pulmonary orifices
and divides the 'inflow' and 'outflow' tracts of the ventricle. The moderator band is a muscular
bundle crossing the ventricular cavity from the interventricular septum to the anterior wall.
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