Superior vena cava is formed by?: (A) Vitelline veins, (B) Supracardinal vein, (C) Infracardinal vein, (D) Common cardinal vein
Answer is D. Developmentally, the superior vena cava consists of two pas: first and second. The first pa develops from the right anterior cardinal vein caudal to oblique transverse anastomosis. The second pa develops from the right common cardinal vein. Reference: Textbook of clinical embryology, Vishram Singh,1st edition, page no.223-224