Anatomy: Vasculature of the mediastinum

Question 1

Azygous vein?

Answer 1

It drains blood from intercostal veins into the Inferior Vena Cava..

It connect the IVC and the SVC, providing an alternative route in case of blockage.

Question 2

What are the mediastinal branches of the aorta?

Answer 2

• coronary arteries
• (right) brachiocephalic trunk (-> R common carotid & R subclavian)
• left common carotid
• left subclavian
• posterior intercostal arteries
• anterior: bronchial, oesophageal, mediastianal, pericaridal, phernic arteries

Question 3

Thoracic duct?

Answer 3

Drains lymph from most of the body (R and bottom) into the left venous angle.

Question 4

What is the venous angle?

Answer 4

Junction of the internal jugular and subclavian veins.

Question 5

Right lymphatic duct?

Answer 5

Drains lymph from the R upper limb, R thorax and head into the right venous angle.

Question 6

How does the right phrenic nerve reach the diaphragm?

Answer 6

The right phrenic verve (C3,4,5) pierces the diaphragm with the IVC, innervating it.

Question 7

What about the left Phrenic nerve?

Answer 7

It pierces the left dome of the diaphragm, having passed along the anterior surface of the pericardium.

Question 8

The central veins are…

Answer 8

internal jugular veins
subclavian veins
brachiocephalic veins
superior vena cava
iliac veins
femoral veins

Question 9

Where is the Jugular Venous Pressure (JVP) observed?

Answer 9

On the internal jugular vein.

Patient raised to 45o

< 3cm above the sternal angle is normal

Question 10

Relationship of vagus to phrenic nerve?

Answer 10

Vagus nerve is lateral to the phrenic nerve.

Question 11

Branches of the superior vena cava?

Answer 11

-left brachiocephalic vein
THEN
-right brachiocephalic vein
-right internal jugular vein
-right subcalvian vein

Question 12

Order of nerves, lateral to medial?

Answer 12

• phrenic nerve
• vagus nerve
• recurrent laryngeal

Question 13

Vessels and nerves, from right to left?

Answer 13

-R phrenic
-R internal jugular vein
-right vagus nerve
-R common carotid artery
-R recurrent laryngeal nerve
-trachea
-L recurrent laryngeal nerve
L common carotid artery
-L vagus
-L internal jugular vein
-L phrenic

Question 14

What spinal nerve reami make up the phrenic nerve?

Answer 14

Cervical spinal nerves 3, 4 and 5.

3,4 and 5 keep the diaphragm alive

Question 15

What innervation do the phrenic nerves supply?

Answer 15

• somatic motor to the diaphragm

- somatic sensory to the pericardium, diaphragm and teh parietal pleura.

Question 16

Where does pain from the diaphragm refer to?

Answer 16

Dermatome on the shoulder tip

Question 17

Vagus nerves?

Answer 17

Cranial nerves X

Supply:

• somatic sensory to the palate, laryngopharynx and larynx.
• somatic motor to the pharynx and larynx.
• autonomic parasympathetic to thoracic and abdominal organs.

Question 18

What are the recurrent laryngeal nerves?

Answer 18

branches of the vagus nerve that supply the pharynx and larynx