Human Anatomy - M.M. Kurepina, A.P. Ozhigova, A.A. Nikitina 2010

Cardiovascular system
Ontogeny of the human circulatory system
Development of the vascular network in the embryo

The truncus arteriosus originates from The Heart primordium and divides into two ventral [aortas]... form the dorsal venous plexus of the hand. On the palm, of the two venous arches corresponding to the arterial ones, the deep arch serves as the main venous collector of the hand (Atl. Figs. 71, 72). The main superficial Veins OF THE upper limb are the cephalic and basilic veins.

The cephalic vein (v. cephalica) arises from the deep palmar arch and the dorsal venous network of the hand, running along the lateral aspect of the forearm and arm, receiving superficial veins along its course. The cephalic vein drains into the axillary vein.

The basilic vein (v. basilica) also arises from the deep palmar arch and the superficial dorsal venous network of the hand. Passing onto the forearm, the basilic vein is significantly reinforced by Blood from the cephalic vein via an anastomosis in the cubital fossa—the median cubital vein. In medical practice, the latter is commonly used for intravenous infusions and blood sampling. The basilic vein drains into one of the brachial veins.

The veins of the superficial and deep palmar arches, passing onto the forearm, form two deep ulnar (v. ulnares) and radial (v. radiales) veins, which accompany the corresponding Arteries. From them, blood flows through the arterial arches (homologues of the branchial arteries) into two dorsal aortas, which merge into a single trunk (Atl. Fig. 73). In humans, a total of six pairs of aortic arches are formed, but the I and II arches regress before the subsequent ones develop. The continuations of the roots of the ventral and dorsal aortas transform into the external and internal carotid arteries, respectively. The portion of the ventral aortic ROOT initially leading to the III arch remains as the common carotid artery, while the III arch itself becomes the proximal part of the External Carotid Artery.

The left IV arch transforms into the arch of the aorta, while the right one becomes the brachiocephalic trunk and the root of the right Subclavian Artery. The V arch is short-lived and regresses. In the early stages, branches to the Lungs arise from the ends of the VI arch. Later, the right part of the VI arch detaches from the aortic root and disappears, while the left part persists. It remains connected to the aortic arch by the ductus arteriosus. The initial segment of the ventral aorta divides longitudinally into the pulmonary trunk (a continuation of the right ventricle) and the aorta (a continuation of the left ventricle).

Segmental arteries arise from the dorsal aorta to supply the developing neural tube, and subsequently the Spinal Cord, as well as the body walls. In the cervical region, they also form the subclavian and vertebral arteries, and in the thoracic region, the intercostal arteries. Following the degeneration of the yolk sac, the two vitelline arteries fuse to form the superior mesenteric artery. The celiac trunk and the inferior mesenteric artery develop caudally as outgrowths of the dorsal aorta. As the abdominal Organs and lower limbs are laid down and develop, the vessels supplying them also develop.

Simultaneously with the Arterial System, the venous System of the embryo is established. In the early embryo, the main veins are the symmetrical cardinal veins. The anterior cardinal veins are small vessels that collect blood from the HEAD. At the level of the heart, they join the posterior cardinal veins—the main drainage Vessels of the posterior half of the body—to form the common cardinal veins (Atl. Fig. 79). They run within the ventrolateral body walls and drain into the sinus venosus. At later Selection/3.html">Stages of development, the SUPERIOR VENA CAVA forms from the anterior cardinal veins, and the INFERIOR VENA CAVA forms from the posterior cardinal veins. During development, the venous flow shifts to the right side of the heart, reflecting an adaptation to pulmonary Respiration.

The umbilical veins carry blood from the Placenta through the connecting stalk to the embryo. Upon entering the embryo's body, they initially run to the sinus venosus of the heart, but after the Liver is formed, they connect with its vascular plexus. Within the umbilical cord, the veins fuse with each other, resulting in only a single umbilical vein remaining.