What is the anatomy of the mediastinum in relation to intravascular intervention

Question 1

What is dysphagia?

Answer 1

Difficulty swallowing

Question 2

Where is the mediastinum?

Answer 2

area between the lungs

Question 3

What are the borders of the mediastinum?

Answer 3

o superior: thoracic inlet (bounded by ribs 1, T1 vertebrae & jugular notch)

o anterior: transverse thoracic plane (between T4/5 intervertebral disc) sternum and fibrous pericardium

o posterior: posterior heart thoracic vertebrae between T4/5

Question 4

What is the thymus?

Answer 4

gland/lymphoid organ producing T lymphocyte in childhood- involutes and becomes replaced by adipose tissue after puberty

Question 5

Where is the thymus?

Answer 5

Anterior mediastinum

Question 6

What does the middle mediastinum contain?

Answer 6

o pericardium
o heart
o parts of the great vessels that connect with the heart;
-inferior part of SVC
-superior part of IVC
-pulmonary trunk and pulmonary arteries
-pulmonary veins
-ascending aorta

Question 7

What does the posterior mediastinum contain?

Answer 7

o the azygous vein: conveys blood from the intercostal veins to the SVC
o sympathetic trunks/chains
o the thoracic duct: carries lymph to venous angle
o vagus nerves
o trachea and 2 main bronchi: the trachea bifurcates at the level of the sternal angle so is in the superior mediastinum
o thoracic aorta: only the thoracic part of the aorta is in the posterior mediastinum

Question 8

Where do the intercostal veins drain into?

Answer 8

posteriorly into the azygous vein

Question 9

What are the mediastinal branches from aorta?

Answer 9

o coronary arteries
o brachiocephalic trunk
o left common carotid
o left subclavian artery
o bilateral posterior intercostal arteries (one per space)

Question 10

What are the anterior branches of the aorta?

Answer 10

• bronchial arteries (arterial blood for lung tissue
• oesophageal arteries
• mediastinal arteries
• pericardial arteries
• phrenic arteries

Question 11

What is the aortic hiatus?

Answer 11

Opening in the diaphragm

Question 12

Where does the right lymphatic duct drain?

Answer 12

Drains the right side of the head, right arm, right thorax into the right venous angle

Question 13

Where does the thoracic duct drain?

Answer 13

Drains left head, left thorax and lower body into left venous angle

Question 14

What does the trachea play a key role in?

Answer 14

Speech

Question 15

What is the surface anatomy of the left venous angle?

Answer 15

Left sternoclavicular joint

Question 16

What is the cysternae chyli?

Answer 16

Swollen part of the thoracic duct in abdomen

Question 17

What is the path of the right phrenic nerve?

Answer 17

passes through the diaphragm with the IVC to supply the diaphragm from the inferior aspect

Question 18

What is the path of the left phrenic nerve?

Answer 18

pierces through the left dome of the diaphragm to supply it from the inferior aspect

Question 19

What is the ligamentum arteiosum?

Answer 19

remnant of the ductus arteriosus

Question 20

Describe the anatomy of the superior mediastinum from anterior to posterior

Answer 20

• brachiocephalic veins & SVC
• arch of aorta & the origin of its 3 branches
• trachea
• oesophagus
• thoracic duct

Question 21

Describe the anatomy of the superior mediastinum from lateral to medial?

Answer 21

• phrenic nerves
• vagus nerves
• recurrent laryngeal nerves

Question 22

What are the central veins?

Answer 22

large veins close to the heart such that the pressure is said to be approximately the pressure in the RA

Question 23

How can we access the central veins?

Answer 23

o	internal jugular vein
o	brachiocephalic vein
o	SVC
o	right atrium
o	inferior vena cava
o	iliac veins
o	femoral veins

Question 24

What the the JVP like in the anatomical position?

Answer 24

the internal jugular veins contain little blood and are collapsed flat

Question 25

What causes the double pulsation?

Answer 25

atrial contraction then filling of the right atrium against a closed tricuspid valve causes a double pulsation pressure wave conducted in a retrograde direction into the central veins that can be observed in the internal jugular vein

Question 26

What is the path of the left and right laryngeal nerve?

Answer 26

Right recurrent laryngeal nerve: hooks under the right subclavian artery: does not enter the chest

left recurrent laryngeal nerve: hooks under the arch of the aorts: does enter chest

Question 27

What are the phrenic nerves formed from?

Answer 27

combined anterior rami of cervical spinal nerves 3. 4 and 5

Question 28

What is the function of the phrenic nerves?

Answer 28

-somatic motor to diaphragm
-somatic sensory to;
o mediastinal parietal pleura
o fibrous pericardium
o diaphragmatic parietal pleura
o diaphragmatic parietal peritoneum

Question 29

What cranial nerve is known as vagus?

Answer 29

X

Question 30

What does the vagus nerve contain?

Answer 30

o somatic sensory nerves for the palate, laryngopharynx and larynx
o somatic motor nerves for the pharynx and larynx
o autonomic parasympathetic nerves for the thoracic and abdominal organs

Question 31

What are recurrent laryngeal nerves branches of?

Answer 31

branches of the vagus nerve that supply the pharynx and larynx

Question 32

What do the vagus nerves contain after they give off their recurrent laryngeal branches?

Answer 32

Only parasympathetic efferents

Question 33

How does pain become referred from the diaphragm?

Answer 33

1) irritates the parietal peritoneum lining the inferior surface of the diaphragm, which is supplied by the phrenic nerve (C3, 4, 5)
2) the supraclavicular nerves (C3, 4) supply the dermatomes over the shoulder tip and enter the spinal cord at the same levels as the phrenic nerve
3) but the brain ‘refers’ the pain to the more superficial structure, the

Question 34

What does the cephalic vein supply?

Answer 34

superficial vein of the upper limb

Question 35

Where is the pulse in the neck?

Answer 35

-bifurcation of the common carotid artery (also site for auscultating carotid bruits)
o anterior to sternocleido-mastoid muscle at level of superior border of thyroid cartilage

Question 36

Where is the brachial pulse located?

Answer 36

o medial to the biceps brachii tendon in the cubital fossa

Question 37

Where is the radial pulse located?

Answer 37

o lateral to the tendon of the flexor carpi radialis

Question 38

Where is the femoral pulse located?

Answer 38

o inferior to midpoint of inguinal ligament

Question 39

Where is the popliteal pulse located?

Answer 39

o in popliteal fossa (immediately posterior to knee joint)

Question 40

Where is the posterior tibial pulse located?

Answer 40

o between the posterior border of the medial malleolus and the Achilles tendon

Question 41

Where is the dorsalis pedis pulse located?

Answer 41

o medial to tendon of the extensor halicus longus on the dorsum of the foot

Question 42

What interventions occur via the radial artery?

Answer 42

cannulation for arterial blood pressure monitor/ABG sampling

Question 43

What interventions occur via the femoral artery?

Answer 43

intravascular interventions

Question 44

What interventions occur via the subclavian artery?

Answer 44

insertion of cardiac pacing wire under ultrasound guidance

Question 45

What interventions occur via the femoral vein?

Answer 45

insertion of central lines and intravascular interventions

Question 46

What interventions occur via the jugular vein?

Answer 46

insertion of central line under ultrasound guidance