Development of arteries

At the third week of the development of the embryo, two ventral aorta extend from the arterial trunk. Six pairs of aortic arches connect the ventral aorta with the initial sections of the right and left dorsal aorta. The aortic arches of I, II and V are soon reduced, so the main role in the formation of arteries of the head, neck and thoracic cavity is played by III, IV and VI aortic arches, as well as sections of the right and left ventral and dorsal aortas. The anterior portion of each ventral aorta (from I to III of the aortic arch) is transformed into an external carotid artery. Each third aortic arch and anterior section of the dorsal aorta is transformed into an internal carotid artery. The section of the dorsal aorta between the third and fourth aortic arches is reduced, and the corresponding section of the ventral aorta becomes a common carotid artery. The left IV arc becomes the arch of the definitive aorta that connects the ascending and descending parts of the aorta. The right dorsal aorta (posterior to the IV right aortic arch) is reduced, the IV right aortic arch becomes the proximal part of the subclavian artery. The section of the right ventral aorta (between the right III and IV aortic arcs) from which it departs turns into a short sphenoplegovolnoy trunk; its branches, thus, are the right carotid and right subclavian artery. The left subclavian artery develops not from the aortic arches, but due to one of the intersegmental dorsal arteries - the branches of the left dorsal aorta. As a result, from the definitive arc of the aorta, the brachiocephalic trunk, the left common carotid and left subclavian artery, depart.

The sixth pair of aortic arcs after separation of the arterial trunk into the ascending part of the aorta and the pulmonary trunk becomes pulmonary arteries. The right VI arc loses its connection with the dorsal aorta, and its distal site is completely reduced. The left VI aortic arch retains its connection to the left dorsal aorta in the form of a wide arterial (botallova) duct, along which the fetus carries blood from the pulmonary trunk to the aorta; After birth, the duct empties, and instead of it remains an arterial ligament.

Intersegmentary dorsal arteries undergo a number of changes. Each of these arteries is subdivided into the dorsal and ventral branches. In the neck and head regions, a vertebral artery is formed from their dorsal branches, and the basilar artery and its branches are closer to the front (cranial). In the trunk region, intersegmental arteries are transformed into posterior intercostal arteries, blood supplying the body walls. The left subclavian artery and the distal part of the right subclavian artery are formed from the ventral branches.

The segmentation of the lining of the lateral and ventral arteries of the embryo body during development is disrupted. Of the lateral segmental arteries, paired diaphragmatic, renal, adrenal and ovarian (ovarian) arteries are formed. From the ventral segmental arteries, unpaired arteries develop, blood supplying the abdominal cavity organs: the celiac trunk, the superior and inferior mesenteric arteries. Caudally located ventral segmental arteries are transformed into right and left umbilical arteries. From the beginning of each of them the axial artery of the lower extremity departs. Subsequently, the axial artery undergoes a reverse development, and in an adult is represented by a thin peroneal artery and a very thin artery accompanying the sciatic nerve. As the organs of the small pelvis and especially the lower extremities form, the ileal arteries (general, external and internal) reach considerable development. The umbilical artery becomes a branch of the internal iliac, and the external iliac in the form of the main arterial highway continues to the lower limb into the femoral, popliteal, anterior and posterior lumbar arteries.

[1], [2], [3], [4], [5], [6], [7], [8], [9]