👉 The beginning veins, also known as the venous plexuses or venous sinuses, are small networks of veins that form early in fetal development. These veins connect the capillaries within the developing fetus to larger veins, allowing blood to drain from the fetal circulation into the mother's bloodstream. The venous plexuses are located throughout the fetus, particularly in areas like the head and neck, and eventually give rise to the major venous sinuses present at birth. These structures play a crucial role in the transition from fetal to postnatal circulation by facilitating blood flow back to the placenta for oxygenation and nutrient exchange.
