Tracheobrachial Tree

Question 0

Shorter

Wider

Shallower angle

3 lobar bronchi branches
- upper, middle, lower
⬇️
10 segmental bronchi

Answer 0

R main bronchus

Question 1

16-20 U-shaped hyaline cartilages & tracheal is muscle

Begins just inferior to cricoids cartilage (C6) & ends at sternal angle (T4)

Answer 1

Trachea

Question 2

2 lobar bronchi
- upper & lower
⬇️
8-10 segmental bronchi

Answer 2

L main bronchus

Question 3

Clinical considerations of tracheobronchial free

Answer 3

Compression of the trachea due to enlarged thyroid gland, aortic arch aneurysm

Metastasis of bronchogenic CA to tracheobronchial LN or left atrial enlargement –> distorted position of carina

Aspiration of foreign objects

Question 4

Aspiration of foreign objects

Answer 4

Sitting/standing:

• R lower lobe bronchus (ENTRY)
• lower portion of R lower lobe (LODGES)

Supine:

• R lower lobe bronchus (ENTRY)
• Upper portion of R lower lobe (LODGES)

Lying on the right side

• R upper lobe bronchus (ENTRY)
• Posterior R upper lobe (LODGES)

Lying on the left side

• L upper lobe (ENTRY)
• Lingula of the L upper lobe (LODGES)

Question 5

Permanent dilatation of airways due to chronic necrotizing infection (Staph, Strep, H. Influenza). Obstruction, Kartgener syndrome (absence of cilia prevents bacterial clearance) or cystic fibrosis

Usually affects lower lobes, saccular appearance

Answer 5

Bronchiectasis

Question 6

Bronchogenic carcinoma

Peripheral (from distal airways & alveoli)

Less associated with smoking

Answer 6

Adenocarcinoma (35%)

Question 7

Bronchogenic carcinoma

Central (from larger bronchi)

Smoking
Paraneoplastic syndrome (PTH-->hypercalcemia)

Answer 7

Squamous cell carcinoma (25%)

Question 8

Bronchogenic carcinoma

Central (from larger bronchi)

Highly malignant
Arise from Kutchitsky cells
Paraneoplastic (ACTH –> Cushing syndrome; ADH –> SIADH)

Answer 8

Small cell (oat cell) carcinoma (15%)

Question 9

Intrathoracic spread of bronchogenic CA may lead to

Answer 9

Horner syndrome = miosis (paralysis of dilator papillae) + ptosis (paralysis of superior tarsal muscle)

SVC syndrome –> dilatation of head & neck veins, facial swelling & cyanosis

Dysphagia (esophageal obstruction)

Hoarseness (recurrent laryngeal nerve)

Paralysis of the diaphragm (phrenic nerve)

Pancoast tumor –> ulnar nerve pain & Horner syndrome

Metastasis to the brain via arterial blood
- lung capillary –> pulmonary vein –> LA –> LV –> internal carotid & vertebral artery

Metastasis to the brain via venous blood
- bronchial vein –> Azygous vein –> external & internal vertebral plexus –> cranial dural sinus