SUPERIOR VENA CAVA # FORMATION/COURSE/ IMP RELATIONS/TRIBUTARIES# SVC ( OBSTRUCTION ,SYNDROME)
The superior vena cava is a venous trunk which carries deoxygenated blood from the circulatory system towards the heart.
The superior vena cava (SVC, also known as the cava or cva) is a short, but large diameter vein located in the anterior right superior mediastinum. Embryologically, the SVC is formed by the left and right brachiocephalic veins (also known as the innominate veins) that also receive blood from the upper limbs, eyes, and neck.
There is no valve that divides the SVC from the right atrium, which conducts blood from right atrial and right ventricular contractions upwards into the internal jugular vein (seen as the jugular venous pressure) and sternocleidomastoid muscle.
RELATIONS OF SUPERIOR VENA CAVA
ANTERIORLY :
Sternum
Internal thoracic vessels
POSTERIORLY:
Trachea
Right vagus
MEDIALLY:
Arch of aorta
Brachiocephalic trunk
LATERALLY:
Right lung and pleura
TRIBUTRIES OF
SUPERIOR VENA CAVA
AZYGOUS VEIN
MEDIASTINAL VEINS
PERICARDIAL VIENS
Superior vena cava syndrome occurs when the superior vena cava becomes blocked. This is most commonly due to tumours that either compress the vessel from the outside, or invade the vessel itself.