Basic Sciences - Anatomy of Lungs

Question 1

Approximate vertebral levels of trachea

Answer 1

Cricoid cartilage C6 to Carina T5/6

Question 2

Average length of adult trachea

Answer 2

15cm

Question 3

Approximate diameter of trachea

Answer 3

Same as patient index finger

Question 4

Distance of trachea from suprasternal notch

Answer 4

5cm above

or 8cm above suprasternal notch if neck fully extended

Question 5

Level of thyroid isthmus in relation to trachea

Answer 5

2nd to 4th tracheal rings

Question 6

Muscle forming posterior wall of trachea

Answer 6

Trachealis muscle

Question 7

Structure of cartilaginous rings in bronchi

Answer 7

Complete rings
(vs trachea with incomplete rings)

Question 8

Distance of right upper lobe bronchus from carina

Answer 8

2.5 cm

Question 9

Anatomy of right main bronchus compared to left main bronchus

Answer 9

Right is shorter, wider and more vertical

Question 10

Number of lobes in right lung

Answer 10

3

Question 11

Number of lobes in left ling

Answer 11

2 + lingula (remnant of left middle lobe)

Question 12

Division of each main bronchus

Answer 12

10 functionally separate bronchopulmonary segment with own blood supply and lung parenchyma

Question 13

Names of each bronchopulmonary segment

Answer 13

Question 14

Lung segment most commonly affected by aspiration during supine anaesthesia

Answer 14

Apical segment of right lower lobe (first segmental bronchus to arise posteriorly)

Question 15

Bronchiole wall components

Answer 15

Smooth muscle
No cartilage

Question 16

Principle site of asthma attack affect

Answer 16

Bronchiole (smooth muscle no cartilage)

Question 17

Epithelium of bronchioles

Answer 17

Ciliated cuboidal epithelium

Question 18

Components of alveolar wall

Answer 18

Single fine layer of non ciliated cuboidal epithelium
Fine basement membrane
(Capillary network)

Question 19

Alveolar cell types and function

Answer 19

Type I - gas exchange surface
Type II - produce surfactant

Question 20

Function of surfactant

Answer 20

Prevent alveolar sac collapse

Question 21

Compartments of mediastinum

Answer 21

• Anterior
• Middle (containing pericardium)
• Posterior
• Superior

Question 22

A mass in which mediastinum compartment is major risk factor for anaesthesia

Answer 22

Anterior mediastinum - loss of muscle tone after induction can allow mass to fall back and compress heart / major vessels

Question 23

Nerve innervation of diaphragm

Answer 23

Phrenic nerve (C3,4,5)

Question 24

Range of movement of the diaphragm

Answer 24

1.5 cm during quiet breathing
13 cm during deep breathing

Question 25

Types of intercostal muscles

Answer 25

External Internal Innermost

Question 26

Nerve supply to intercostal muscles

Answer 26

Intercostal nerves T1 to T11

Question 27

Respiratory accessory muscles

Answer 27

Scalene Sternocleidomastoid Alae nasi Small muscles of head and neck

Question 28

Function of scalenes in breathing

Answer 28

Lifts first and second ribs

Question 29

Function of sternocleidomastoids in breathing

Answer 29

Lifts sternum

Question 30

Average depth of ETT in adults male and female

Answer 30

Male - 22 cm at teeth Female 20 cm at teeth

Question 31

Number of ribs that should be visible on CXR on inspiration

Answer 31

10 posterior ribs or 6 anterior ribs