Lower Respiratory Tract

Question 1

Features of LRT

Answer 1

Trachea, bronchi, bronchioles and branches, lungs and pleurae

Question 2

Trachea: Relations

Answer 2

• Inferior continuation of larynx at C6
• Through the thoracic inlet
• To vertebra T4 where it bifurcates into left and right main bronchi
• Oesophagus lies posterior (trachea-oesophageal grooves)
• Common carotid arteries and vagus nerves lie immediately lateral on both sides

Question 3

Trachea: Structure

Answer 3

• 20 C-shaped hyaline cartilage

- Trachealis muscle (posterior)

Question 4

Carina

Answer 4

Final, keel-shaped cartilage ring at bifurcation of trachea

Question 5

Right main bronchus: Structure and relations

Answer 5

• Shorter, wider and more vertical
• Eparterial branch
• Hypoarterial branch (right pulmonary artery arches over)

Question 6

Left main bronchus: Structure and relations

Answer 6

• More acute (arch of aorta arches over)

- Enters lung before it branches

Question 7

LRT: Innervation

Answer 7

Motor:
- Sympathetic fibres Upper thoracic via pulmonary plexuses located at the termination of bronchi
- Parasympathetic fibre
From CNX

Sensory:
- Reach spinal cord via sympathetic/parasympathetic nerves

Question 8

LRT: Arterial supplies

Answer 8

Bronchial arteries (thoracic aorta and intercostal arteries)

Question 9

LRT: Venous supplies

Answer 9

Azygous venous system

Question 10

LRT: Lymphatic drainage

Answer 10

Tracheobronchial nodes: at trachea bifurcation

Bronchomediastinal nodes: at lung hilum

Question 11

Apex of lung

Answer 11

Lies above the first rib

Question 12

Anterior and posterior border of lung

Answer 12

Junction of the mediastinal and costal surface

Question 13

Inferior border of lung

Answer 13

Junction of the costal and diaphragmatic surface

Question 14

Oblique fissure

Answer 14

Right lung: separates middle and lower lobe

Left lung: separates upper and lower lobe

Question 15

Hilum of the lung

Answer 15

Area on medial surface of lung through which structures enter and leave the lung

Question 16

Root of the lung

Answer 16

Structures which enter and leave collectively known as the root.

• Bronchi: most superior
• Pulmonary artery: anterior to bronchus
• Superior pulmonary vein: most anterior
• Inferior pulmonary vein: most inferior
• Nerves
• Lymphatics

Question 17

Features of left lung only

Answer 17

• Cardiac notch
• Cardiac impression
• Lingula
• Aortic impression

Question 18

Features of right lung only

Answer 18

• Middle lobe
• Transverse fissure (between middle and upper lobe)
• Superior lobar (eparterial) bronchus

Question 19

Bronchopulmonary segment

Answer 19

Segment of lung supplied by a tertiary bronchus, pulmonary artery branch, bronchial artery and vein
- Separated by connective tissue

Question 20

Lung and visceral pleura lymphatic drainage

Answer 20

Bronchopulmonary lymph nodes at main bronchus bifurcation

then to tracheobronchial

Question 21

Pleura

Answer 21

Double-layered serous membrane surrounding each lung and continuous around lung root

• Parietal
• Visceral

Question 22

Parietal pleura

Answer 22

• Apical/cervical (or cupola)
• Diaphragmatic
• Costal
• Mediastinal

Question 23

Visceral pleura

Answer 23

• Lungs

- Fissures

Question 24

Cupola attachments

Answer 24

• Suprapleural membrane (fascial membrane)/ SIbson’s fascia

- C7 transverse processes

Question 25

Pleural cavity

Answer 25

Potential space between 2 pleural layers and contains pleural fluid.

Question 26

Pleura innervation

Answer 26

Parietal: phrenic and intercostal nerves (pain sensitive)
Visceral: autonomic nerves (T2-5)

Question 27

Pleural reflections

Answer 27

Occurs where the parietal pleura changes its direction

- Costodiaphragmatic reflection

Question 28

Pleural recess/angle

Answer 28

Increased space between the layers of the pleura occurring at pleural reflections
- Costodiaphragmatic/ costophrenic recess/angle