THORAX III

Question 1

What are the superior, posterior, anterior, lateral and inferior boundaries of the superior mediastinum?

Answer 1

Superior boundaries: Manubrium, T1, ribs 1
Posterior: T1-T4
Anterior: Manubrium
Lateral: Lungs and mediastinal pleura
Inferior: Transverse thoracic plane (T4/5)

Question 2

Before entering the root of the right lung, what does the right pulmonary artery pass posterior too?

Answer 2

The ascending aorta and the superior vena cava

Question 3

Was does the left pulmonary artery run anterior to before entering the left lung root?

Answer 3

The descending thoracic aorta

Question 4

What side of the body does the azygous vein run in?

Answer 4

The right side of the body

Question 5

What’s the function of the azygous vein?

Answer 5

To transport deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava

Question 6

At what level is the azygous vein formed?

Answer 6

T12

Question 7

What is the azygos vein formed from?

Answer 7

The union of the ascending lumbar vein with the right subcostal vein

Question 8

What does the azygous vein arch over after ascending in the posterior mediastinum?

Answer 8

The right main bronchus at the root of the right lung

Question 9

What are the 2 tributaries to the azygous vein?

Answer 9

The hemiazygous vein and the accessory hemiazygous vein

Question 10

What forms the hemiazygous vein?

Answer 10

The oesophageal and mediastinal tributaries, the common trunk of the left ascending lumbar vein and left subcostal vein, and the lower of the 3 posterior intercostal veins

Question 11

The hemiazygous vein ascends anterior to the vertebral column before crossing posterior to the aorta, oesophagus and thoracic duct at what vertebral level?

Answer 11

T8

Question 12

What forms the accessory hemiazygous vein?

Answer 12

Veins from the 4th to 8th intercostal spaces and sometimes by the left bronchial veins

Question 13

At what level does the accessory hemiazygous vein cross to join the azygous vein?

Answer 13

T7

Question 14

From what spinal segments does the right phrenic nerve arise?

Answer 14

C3, C4, C5

Question 15

What does the phrenic nerve provide motor innervation to?

Answer 15

The diaphragm

Question 16

What does the phrenic nerve provide sensory innervation to?

Answer 16

The central part of the diaphragm, the pericardium and the mediastinal part of the parietal pleura

Question 17

What vessels does the right phrenic nerve descend lateral to?

Answer 17

The right brachiocephalic vein and the superior vena cava

Question 18

Does the right phrenic nerve run anterior or posterior to the root of the right lung?

Answer 18

Anterior to the hilum of the right lung

Question 19

What vessel does the left phrenic nerve run lateral to?

Answer 19

The left subclavian artery

Question 20

What nerve does the left phrenic nerve cross superficially as it approaches the aortic arch?

Answer 20

The left vagus nerve

Question 21

Does the left phrenic nerve run anterior or posterior to the root of the left lung?

Answer 21

Anterior

Question 22

What does phrenic nerve damage lead to?

Answer 22

Diaphragmatic paralysis

Question 23

What is the sensory innervation by the vagus nerve?

Answer 23

Innervates the skin of the external acoustic meatus and the internal surfaces of the laryngopharynx and larynx. Provides visceral sensation to the heart and abdominal viscera

Question 24

What’s the special sensory innervation by the vagus nerve?

Answer 24

Provides taste sensation to the epiglottis and the root of the tongue

Question 25

What is the motor innervation by the vagus nerve?

Answer 25

Provides motor innervation to the majority of the muscles of the pharynx, soft palate and larynx

Question 26

What's the parasympathetic innervation by the vagus nerve?

Answer 26

Innervates the smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm

Question 27

Where does the vagus nerve originate?

Answer 27

The medulla oblongata of the brainstem

Question 28

Via what foramen does the vagus nerve exit the cranium?

Answer 28

The jugular foramen

Question 29

What branch arises from the vagus nerve within the cranium?

Answer 29

The auricular branch

Question 30

What does the right vagus nerve pass anterior to to enter the thorax?

Answer 30

The right subclavian artery

Question 31

What does the left vagus nerve pass between to enter the thorax?

Answer 31

The left common carotid and the left subclavian arteries

Question 32

What does the right vagus nerve form in the thorax?

Answer 32

The posterior vagal trunk

Question 33

What does the left vagus nerve form in the thorax?

Answer 33

The anterior vagal trunk

Question 34

What plexus do branches of the vagal trunks contribute to?

Answer 34

The oesophageal plexus

Question 35

What branches off the right vagus nerve just inferior to the right subclavian artery?

Answer 35

The right recurrent laryngeal nerve

Question 36

What's the relationship between the right vagus nerve and the right subclavian artery?

Answer 36

The right vagus nerve's right recurrent laryngeal branch hooks around the right subclavian artery and ascends into the neck between the trachea and oesophagus

Question 37

How does the posterior vagal trunk enter the diaphragm?

Answer 37

With the oesophagus via the oesophageal hiatus at T10

Question 38

What's the relationship between the left vagus nerve and the aortic arch?

Answer 38

The left vagus gives rise to the left recurrent laryngeal, which hooks around the aortic arch to the left of ligamentum arteriosum to then ascend between the trachea and oesophagus

Question 39

Where does the sympathetic chain span from?

Answer 39

From the base of the skull to the coccyx

Question 40

What are the 3 ganglia within the chain that are of interest?

Answer 40

The superior, middle and inferior cervical ganglia

Question 41

What vertebrae is the superior cervical ganglion anterior to?

Answer 41

C1-C4

Question 42

What vertebra is the middle cervical ganglion anterior to?

Answer 42

C6

Question 43

What vertebra is the inferior cervical ganglion anterior to?

Answer 43

C7

Question 44

What is partial ptosis and what causes it?

Answer 44

Partial ptosis is drooping of the upper eyelid, due to paralysis of the superior tarsal muscle, which acts to help open the eyelid

Question 45

What is miosis and what causes it?

Answer 45

Constriction of the pupil due to paralysis of the dilator pupillae, a muscle located within the eye that acts to dilate the pupil

Question 46

What is anhydrosis and what causes it?

Answer 46

Decreased sweating affecting the same side of the face as the lesion, due to a loss of innervation to the sweat glands of the face

Question 47

Why are white rami white?

Answer 47

They have more myelinated preganglionic sympathetic fibres than unmyelinated fibres, unlike in grey rami

Question 48

What's the functions of the upper oesophageal sphincter?

Answer 48

Prevent food from going down the windpipe. Involved when eating, breathing, belching and vomiting

Question 49

What's the functions of the lower oesophageal sphincter?

Answer 49

Prevent stomach acid and contents from traveling backwards from the stomach (regurgitation)

Question 50

Why are the cartilaginous rings of the trachea C-shaped (incomplete)?

Answer 50

To allow the trachea to collapse slightly when swallowing, so food can pass more easily down the oesophagus

Question 51

What's gastro-oesophageal reflux disease?

Answer 51

A common condition where acid from the stomach leaks up into the oesophagus, usually occurring as a result of weakening of the LOS

Question 52

How many cartilaginous rings are there in the trachea?

Answer 52

20

Question 53

What's the name of secondary bronchi?

Answer 53

Lobar bronchi

Question 54

What's the name of tertiary bronchi?

Answer 54

Segmental bronchi

Question 55

What causes tracheal deviation?

Answer 55

Unequal intrathoracic pressure within the thoracic cavity, which may be due to large pleural effusion or tension pneumothorax, pulmonary fibrosis or mediastinal masses

Question 56

What vertebral levels does the oesophagus lie between?

Answer 56

C6-T11

Question 57

What are the names of the 3 constrictions of the oesophagus?

Answer 57

Upper (pharyngeal) constriction Middle (aortic) constriction Inferior (diaphragmatic) constriction

Question 58

What's the purpose of the upper constriction of the oesophagus?

Answer 58

Prevent food going into the trachea

Question 59

What's the purpose of the middle constriction of the oesophagus?

Answer 59

Make room for the heart

Question 60

What's the purpose of the inferior constriction of the oesophagus?

Answer 60

Stop food refluxing from stomach into the oesophagus

Question 61

What is dysphagia and what causes it?

Answer 61

Dysphagia is the inability to swallow. It can be caused by cancer, achalasia, myasthenia gravis, myotonic dystrophy and foreign bodies

Question 62

What is GORD?

Answer 62

Gastro-oesophageal reflux disease

Question 63

What is Barrett's oesophagus?

Answer 63

Abnormal metaplastic change in the mucosal cells lining the lower portion of the oesophagus from normal stratified squamous epithelium to simple columnar epithelium with goblet cells

Question 64

What is the thoracic duct?

Answer 64

The largest lymphatic vessel in the lymphatic system, of about 40cm in length in adults

Question 65

What does the thoracic duct arise from in the abdomen?

Answer 65

The cisterna chyli in the root of the mesentery of the small intestine

Question 66

Where does the thoracic duct empty?

Answer 66

The point where the internal jugular and left subclavian veins join in the neck

Question 67

What does the thoracic duct drain?

Answer 67

It drains the abdomen, pelvis, left thorax, head, neck and both lower limbs

Question 68

What is Chylothorax?

Answer 68

A condition in which there's lymph in the pleural cavity

Question 69

What's a common cause of Chylothorax and why?

Answer 69

Mistakes leading to laceration of the thoracic duct during surgery, which is easy because the thoracic duct is thin-walled and may be colourless

Question 70

What are the 4 main groups of tracheobronchial lymph nodes?

Answer 70

Tracheal, bronchial, bronchopulmonary and pulmonary

Question 71

Where are tracheal lymph nodes found?

Answer 71

Either side of the trachea

Question 72

Where are bronchial lymph nodes found?

Answer 72

In the angles between the lower part of the trachea and bronchi and in the angle between the 2 bronchi

Question 73

Where are the bronchopulmonary lymph nodes found?

Answer 73

In the hilum of each lung

Question 74

Where are the pulmonary lymph nodes found?

Answer 74

In the parenchyma, on the larger branches of the bronchi.