Anatomy of the Airways, Lungs and Pleura

Question 1

Extent of the trachea

Answer 1

C6 - T5

Question 2

Point where trachea branches into right and left

Answer 2

Carina

Question 3

How are the airways kept from collapsing in the lungs?

Answer 3

U-shaped cartilaginous rings
Fibrous membrane surrounding the trachealis muscle

Question 4

How many levels are there in the bronchial tree?

Answer 4

23

Question 5

How is the division of the trachea into right and left assymetric?

Answer 5

Right main bronchus: Widens and branches at a small angle away from the trachea
Left main bronchus: (1) Smaller in diameter than the right, (2) Branches at a greater angle because of the heart

Question 6

Where do inspired foreign bodies often get stuck?

Answer 6

Right main bronchus

The right main has a larger diameter and branches from the trachea at a smaller angle than the left

Question 7

How are the main bronchi held open?

Answer 7

U-shaped cartilage

Cartilage can be identified on a bronchoscopy

Question 8

What are lobar bronchi?

Answer 8

Branch from the main bronchi into the five lobes of the lungs (3 right and 2 left)
Formed from the second and third generation of branching

Lobar bronchi branch into segmental bronchi which form the bronchopulmonary segments of the lungs (see lungs flashcards)

Question 9

High thoracic pressure (such as in forced expiration) may cause …

Answer 9

Segmental and lobar bronchi to collapse because of irregular patterns of cartilage surrounding the airways

Question 10

In which patients are the bronchi susceptible to collapse?

Answer 10

Patients with obstructive pulmonary disorders, e.g. asthmatics or people with chronic obstructive pulmonary disease

Question 11

Bronchiole generation in bronchial tree

Answer 11

12

Question 12

How are bronchioles held open?

Answer 12

Elasticity of the lung tissue

Question 13

What is the conducting zone?

Answer 13

Trachea to terminal bronchioles

Question 14

What is the respiratory zone?

Answer 14

Terminal bronchioles to the final alveoli

Question 15

Constituents of the respiratory zone

Answer 15

Respiratory bronchioles and alveoli (generation 23)

Question 16

What is mesothelium?

Answer 16

Simple squamous epithelium that covers organs within the thoracic or abdominal space

Question 17

Width of the pleural space?

Answer 17

10-20µm wide

Question 18

How do the pressures in the lungs prevent them from collapsing?

Answer 18

Intrapleural pressure (pressure in the pleural space) is less than the pressure in the lungs (alveolar pressure) which creates a vacuum preventing the lungs from collapsing

Question 19

What is transpulmonary pressure?

Answer 19

Difference between alveolar and intrapleural pressure

Question 20

Cause of pleuritic pain

Answer 20

Irritation of parietal pleura from malignancy, infection, lung collapse and trauma (MILCT)

Question 21

How is pleuritic pain detected?

Answer 21

Sensed by somatic fibers (from the intercostal nerves over the chest wall parietal pleura) and by the phrenic nerve (over the diaphragmatic parietal pleura)

Question 22

What is Kehr’s sign

Answer 22

C3 and C4 innervate the diaphragm and area around each shoulder
Kehr sign: When irritation of diaphragmatic parietal pleura causes referred pain to the shoulder
Manipulation of the diaphragm during abdominal surgery, liver infection or gallbladder pathology may cause Kehr sign over the right shoulder
A ruptured spleen can cause Kehr sign over the left shoulder

Question 23

Mesothelioma

Answer 23

Mesothelial cells making up the pleura can become neoplastic after exposure to asbestos, leading to mesothelioma