Superior Vena Cava

Question 1

Length and diameter

Answer 1

7,1.25cm

Question 2

It lies in which all mediastinum

Answer 2

Superior and middle

Question 3

First sign of mediastinal syndrome

Answer 3

Signs of obstruction of SVC

Question 4

How is it formed?

Answer 4

At the lower border of the first right costal cartilage by the union of right and left brachiocephalic veins . It passes vertically download behind the right border of the sternum and pierces the pericardium at the level of the right second costal cartilage and opens into the upper part of the right atrium at the lower border of the right third costal cartilage.

Question 5

Name the veins that does not have valves

Answer 5

Superior Vena cava ,brachiocephalic vein and azygos vein

Question 6

Anterior relations

Answer 6

Right internal thoracic vessels
Margin of right lung and pleura
Chest wall

Question 7

Posterior relations

Answer 7

Trachea( posteromedial)

Right pulmonary artery and right bronchus

Question 8

Left side relations

Answer 8

Ascending aorta anteromedial

Pulmonary trunk

Question 9

Right side relations

Answer 9

Right phrenic nerve and pericardiophrenic vessels

Right lung and pleura

Question 10

Tributaries of superior Vena cava

Answer 10

Right and left brachiocephalic veins
Azygos vein which arches over the root of the right lung and opens into the superior Vena cava just before it pierces the fibrous pericardium
Mediastinal and pericardial veins

Question 11

Comment on brachiocephalic burns and the difference of both sides

Answer 11

Each of the brachiocephalic vein is formed behind the sternoclavicular joint by the union of the corresponding internal jugular and subclavian veins.
Right brachiocephalic vein is short (2.5 CM) .It is vertical, runs vertically downward from the right sternoclavicular joint to the lower margin of the right first costal cartilage. Tributaries are 1.right vertebral vein
2. right internal thoracic vein
3.right inferior thyroid vein
4. right first posterior intercostal vein.
The left brachiocephalic vein is long (6cm)is oblique runs across the superior mediastinum from the left sternoclavicular joint to the lower margin of the first right first costal cartilage. the tributaries are
1. left vertebral vein
2. left internal thoracic vein left inferior thyroid vein
3. first left posterior intercostal vein
4. left superior intercostal vein..

Question 12

Clinical correlation

Answer 12

Obstruction of SVC above and below the opening of azygos vein.
If superior Vena cava is obstructed abovr the opening of the azygos vein, the venous blood from the upper half of the body is shunted to the right atrium through the azygos vein. The main collateral pathways are provided by the superior intercostal vein. The superficial veins of the chest wall do not receive sufficient blood to cause their prominence if at all they become prominent, the prominence is limited up to the costal margin only.
If superior Vena cava is obstructed below the opening of azygos vein ,the venous blood from the upper half of the body is returned to the right atrium through the inferior Vena cava. Clinically under this condition,a subcutaneous anastomotic chsnn is formed between the superficial epigastric vein and lateral thoracic vein. Seen in the sbterot aspect of the thoraco abdominal wall.

Question 13

Digaram

Answer 13

There are 3 diagrams.vk and learn.😃