Basic Sciences - Anatomy of Lungs Flashcards
Approximate vertebral levels of trachea
Cricoid cartilage C6 to Carina T5/6
Average length of adult trachea
15cm
Approximate diameter of trachea
Same as patient index finger
Distance of trachea from suprasternal notch
5cm above
or 8cm above suprasternal notch if neck fully extended
Level of thyroid isthmus in relation to trachea
2nd to 4th tracheal rings
Muscle forming posterior wall of trachea
Trachealis muscle
Structure of cartilaginous rings in bronchi
Complete rings
(vs trachea with incomplete rings)
Distance of right upper lobe bronchus from carina
2.5 cm
Anatomy of right main bronchus compared to left main bronchus
Right is shorter, wider and more vertical
Number of lobes in right lung
3
Number of lobes in left ling
2 + lingula (remnant of left middle lobe)
Division of each main bronchus
10 functionally separate bronchopulmonary segment with own blood supply and lung parenchyma
Names of each bronchopulmonary segment
Lung segment most commonly affected by aspiration during supine anaesthesia
Apical segment of right lower lobe (first segmental bronchus to arise posteriorly)
Bronchiole wall components
Smooth muscle
No cartilage
Principle site of asthma attack affect
Bronchiole (smooth muscle no cartilage)
Epithelium of bronchioles
Ciliated cuboidal epithelium
Components of alveolar wall
Single fine layer of non ciliated cuboidal epithelium
Fine basement membrane
(Capillary network)
Alveolar cell types and function
Type I - gas exchange surface
Type II - produce surfactant
Function of surfactant
Prevent alveolar sac collapse
Compartments of mediastinum
- Anterior
- Middle (containing pericardium)
- Posterior
- Superior
A mass in which mediastinum compartment is major risk factor for anaesthesia
Anterior mediastinum - loss of muscle tone after induction can allow mass to fall back and compress heart / major vessels
Nerve innervation of diaphragm
Phrenic nerve (C3,4,5)
Range of movement of the diaphragm
1.5 cm during quiet breathing
13 cm during deep breathing
Types of intercostal muscles
External
Internal
Innermost
Nerve supply to intercostal muscles
Intercostal nerves T1 to T11
Respiratory accessory muscles
Scalene
Sternocleidomastoid
Alae nasi
Small muscles of head and neck
Function of scalenes in breathing
Lifts first and second ribs
Function of sternocleidomastoids in breathing
Lifts sternum
Average depth of ETT in adults male and female
Male - 22 cm at teeth
Female 20 cm at teeth
Number of ribs that should be visible on CXR on inspiration
10 posterior ribs
or
6 anterior ribs
