Aortic septum
Encyclopedia
In the developing heart
, the truncus arteriosus
and bulbus cordis
are divided by the aortic septum. This makes its appearance in three portions.
(1) Two distal ridge-like thickenings project into the lumen of the tube; these increase in size, and ultimately meet and fuse to form a septum, which takes a spiral course toward the proximal end of the truncus arteriosus
. It divides the distal part of the truncus into two vessels, the aorta and pulmonary artery, which lie side by side above, but near the heart the pulmonary artery
is in front of the aorta
.
(2) Four endocardial cushions
appear in the proximal part of the truncus arteriosus in the region of the future semilunar valves; the manner in which these are related to the aortic septum is described below.
(3) Two endocardial thickenings—anterior and posterior—develop in the bulbus cordis and unite to form a short septum; this joins above with the aortic septum and below with the ventricular septum. The septum grows down into the ventricle as an oblique partition, which ultimately blends with the ventricular septum in such a way as to bring the bulbus cordis into communication with the pulmonary artery
, and through the latter with the sixth pair of aortic arches
; while the left ventricle is brought into continuity with the aorta, which communicates with the remaining aortic arches.
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, the truncus arteriosus
Truncus arteriosus (embryology)
The truncus arteriosus and bulbus cordis are divided by the aorticopulmonary septum. The truncus arteriosus gives rise to the ascending aorta and the pulmonary trunk. The caudal end of the bulbus cordis gives rise to the smooth parts of the left and right ventricles...
and bulbus cordis
Bulbus cordis
The bulbus cordis lies ventral to the primitive ventricle after the developing heart assumes its S-shaped form...
are divided by the aortic septum. This makes its appearance in three portions.
(1) Two distal ridge-like thickenings project into the lumen of the tube; these increase in size, and ultimately meet and fuse to form a septum, which takes a spiral course toward the proximal end of the truncus arteriosus
Truncus arteriosus
Truncus arteriosus may refer to:*Persistent truncus arteriosus, a rare congenital heart disease*Truncus arteriosus , part of an embryo's developing circulatory system...
. It divides the distal part of the truncus into two vessels, the aorta and pulmonary artery, which lie side by side above, but near the heart the pulmonary artery
Pulmonary artery
The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....
is in front of the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
.
(2) Four endocardial cushions
Endocardial cushions
Atrioventricular cushions or endocardial cushions refers to a subset of cells in the primordial heart that play a vital role in proper heart septation.They develop on the atrioventricular canal.During development the heart starts out as a tube...
appear in the proximal part of the truncus arteriosus in the region of the future semilunar valves; the manner in which these are related to the aortic septum is described below.
(3) Two endocardial thickenings—anterior and posterior—develop in the bulbus cordis and unite to form a short septum; this joins above with the aortic septum and below with the ventricular septum. The septum grows down into the ventricle as an oblique partition, which ultimately blends with the ventricular septum in such a way as to bring the bulbus cordis into communication with the pulmonary artery
Pulmonary artery
The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....
, and through the latter with the sixth pair of aortic arches
Aortic arches
The aortic arches or pharyngeal arch arteries are a series of six paired embryological vascular structures which give rise to several major arteries...
; while the left ventricle is brought into continuity with the aorta, which communicates with the remaining aortic arches.