In this video we will consider the anatomical features of the superior vena cava system.

The superior vena cava (vena cava superior) is one of the largest veins in our body.

It is located in the mediastinum, has no valves, drains blood from the head, neck, and superior half of the trunk, including the upper limbs.

It is formed by the fusion of two brachiocephalic veins (v. brachiocephalica dextra et v. brachiocephalica sinistra) at the junction of the first rib with the sternum. At the level of the third rib, it ends by the right atrium.

The brachiocephalic veins are formed from the subclavian vein (v. subclavia) and the internal jugular vein (v. jugularis interna) on the right and left, respectively.

They are large valveless muscular veins.

Major tributaries of the brachiocephalic veins are the following veins:

1. The vertebral vein (v.vertebralis), which passes along the vertebral column through the foramina transversaria of the vertebrae. It accompanies the artery of the same name. The internal vertebral plexuses end by it.

   

2. The deep cervical vein (v.cervicalis profunda) is located behind the transverse processes of the cervical vertebrae. It drains blood from the muscles and fascia of the occipital region.

The right and left brachiocephalic veins also drain blood from the thoracic organs.

The main major tributaries of the superior vena cava include the following veins:

1. The azygos vein (v. azygos)

   

   

2. The hemi-azygos vein (v. hemiazygos)

   

   

3. Posterior intercostal veins (vv. intercostales posteriores)

   

4. Internal thoracic vein (v.thoracica interna)

   

5. Internal (anterior and posterior) vertebral venous plexuses (plexus venosi vertebrales interni (anterior et posterior))

Let’s consider them in greater detail:

1. The azygos vein (v.azygos) is a large muscular venous vessel, which contains valves. It arises from the right ascending lumbar vein (v. lumbalis ascendens dextra).

   

   

   

   In turn, this vein anastomoses with the right lumbar veins (v. lumbalis dextra), which end by the inferior vena cava.

   

   The hemi-azygos vein (v. hemiazygos) and the veins of the following thoracic cavity end by the azygos vein:

   

   

   • the right superior intercostal vein (v. intercostales dexter superior)

     

   • 4th-11th posterior intercostal veins (vv. intercostales IV—XI posterior)

     

   • esophageal veins (vv. oesophageales)

   • bronchial veins (vv. bronchiales)

     

   • pericardial veins (vv pericardiacae)

   • mediastinal veins (vv. mediastinales)

     

2. The hemi-azygos vein (v. hemiazygos) arises from the left ascending lumbar vein (v. lumbalis ascendens sinistra) and passes to the left of the aorta and in front of the left posterior intercostal arteries. It ends by the azygos vein.

   

   

   

   Tributaries of the hemi-azygos vein are:

   • the accessory hemi-zygos vein (v.hemiazygos accessoria), by which the superior posterior intercostal veins end

     

   • esophageal veins (vv.oesophageales)

     

   • mediastinal veins (vv.mediastinales)

3. Posterior intercostal veins (vv. inlercostales posteriores) are located parallel to the arteries of the same name. They end by the azygos and hemi-azygos veins and communicate with the anterior intercostal veins.

   

4. The internal thoracic vein (v. thoracica interna) is accompanied by the internal thoracic artery along the edge of the sternum. It is formed by the confluence of the superior epigastric vein (v. epigastrica superior) and the musculophrenic vein (v. musculophrenica).

5. Internal (anterior and posterior) vertebral venous plexuses (plexus venosi vertebrales interni (anterior et posterior)) pass inside the vertebral canal. They are formed by multiple anastomoses. These plexuses drain blood from the spinal veins and the veins of the spongy bone of the vertebrae.

Venous outflow from the upper limbs is also carried out into the superior vena cava system. Through the superficial and deep groups of veins. The superficial tributaries of the veins of the upper limb include:

• the cephalic vein (v. cephalica) is formed from the radial part of the veins of the dorsum of the hand.

  

• the basilic vein (v. basilica) arises from the dorsal metacarpal vein.

  

  The deep tributaries of the veins of the upper limb include:

• the radial vein (v. radialis), which arises from the deep venous palmar arch.

  

• the ulnar vein (v. ulnaris), which arises from the deep venous palmar arch.

  

• the brachial vein (v. brachialis), which is formed by the confluence of the radial and ulnar veins.

  

• the axillary vein (v. axillaris) is a continuation of the brachial vein.

  

• the subclavian vein (v.subclavia) aries from the axillary vein.

Dictionary

The superior vena cava

Superior vena cava

vena cava superior

Right and leftbrachiocephalic veins

vv. brachiocephalicae dextra et sinistra

Vertebral vein

v. vertebralis

Deep vein of the neck

v. cervicalis profunda

Azygos vein

v. azygos

Right ascending lumbar vein

v. lumbalis ascendens dextra

Right lumbar vein

v. lumbalis dextra

Right superior intercostal vein

v. intercostalis dextra superior

Posterior intercostal veins IV—XI

vv. intercostales IV—XIposteriores

Hemi-azygos vein

v. hemiazygos

Left ascending lumbar vein

v. lumbalis ascendens sinistra

Accessory hemi-azygos vein

v. hemiazygos accessoria

Mediastinal veins

vv. mediastinales

Posterior intercostal veins

vv. intercostales posteriores

Intervertebral vein

v. intervertebralis

Internal thoracic vein

v. thoracica interna

Superior epigastric veins

v. epigastrica superior

Internal vertebral venous plexuses

plexus venosi vertebrates interni

External venous vertebral plexuses

plexus venosi vertebrates externi

Lumbar veins

vv. lumbales