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Atlas of Human Embryos Chapter   Figure

T-4 spinal ganglion, atrioventricular sulcus, bronchopulmonary bud(s), digit 5, erector spinae muscle group, interventricular septum (membranous part), left atrium, left common cardinal vein, mammary gland primordium, marginal vein, mesocardium (caudal part), musculi pectinati in wall of right atrium, ostium secundum, pericardial cavity, postcardinal segment, right atrioventricular canal, right atrium, right primary bronchus, right pulmonary artery, right venous valve, septum primum, septum secundum, shaft of rib 4, sinus venosus, sternal bar, sympathetic trunk, trabeculae carneae cordis in wall of right ventricle, transversospinal muscle group, vagus nerve (CN X)

A section through the T-4 spinal ganglion and the right atrioventricular (A-V) canal.

Observe:
1. The trabeculae carneae cordis in the wall of the right ventricle and the musculi pectinati in the right atrial wall.
2. The sinus venosus between the septum secundum and right venous valve.
3. The entrance of the left common cardinal vein into the pericardial cavity, then passing toward the right, dorsal to the heart.
4. The right pulmonary artery coursing into the lung ventral to the right primary bronchus.
5. The primordium of the mammary gland and fifth digit of the hand.


Keywords: T-4 spinal ganglion, atrioventricular sulcus, bronchopulmonary bud(s), digit 5, erector spinae muscle group, interventricular septum (membranous part), left atrium, left common cardinal vein, mammary gland primordium, marginal vein, mesocardium (caudal part), musculi pectinati in wall of right atrium, ostium secundum, pericardial cavity, postcardinal segment, right atrioventricular canal, right atrium, right primary bronchus, right pulmonary artery, right venous valve, septum primum, septum secundum, shaft of rib 4, sinus venosus, sternal bar, sympathetic trunk, trabeculae carneae cordis in wall of right ventricle, transversospinal muscle group, vagus nerve (CN X)

Source: Atlas of Human Embryos.