Anatomy of the Airways, Lungs and Pleura Flashcards
Extent of the trachea
C6 - T5
Point where trachea branches into right and left
Carina
How are the airways kept from collapsing in the lungs?
U-shaped cartilaginous rings
Fibrous membrane surrounding the trachealis muscle
How many levels are there in the bronchial tree?
23
How is the division of the trachea into right and left assymetric?
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
Where do inspired foreign bodies often get stuck?
Right main bronchus
The right main has a larger diameter and branches from the trachea at a smaller angle than the left
How are the main bronchi held open?
U-shaped cartilage
Cartilage can be identified on a bronchoscopy
What are lobar bronchi?
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)
High thoracic pressure (such as in forced expiration) may cause …
Segmental and lobar bronchi to collapse because of irregular patterns of cartilage surrounding the airways
In which patients are the bronchi susceptible to collapse?
Patients with obstructive pulmonary disorders, e.g. asthmatics or people with chronic obstructive pulmonary disease
Bronchiole generation in bronchial tree
12
How are bronchioles held open?
Elasticity of the lung tissue
What is the conducting zone?
Trachea to terminal bronchioles
What is the respiratory zone?
Terminal bronchioles to the final alveoli
Constituents of the respiratory zone
Respiratory bronchioles and alveoli (generation 23)
What is mesothelium?
Simple squamous epithelium that covers organs within the thoracic or abdominal space
Width of the pleural space?
10-20µm wide
How do the pressures in the lungs prevent them from collapsing?
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
What is transpulmonary pressure?
Difference between alveolar and intrapleural pressure
Cause of pleuritic pain
Irritation of parietal pleura from malignancy, infection, lung collapse and trauma (MILCT)
How is pleuritic pain detected?
Sensed by somatic fibers (from the intercostal nerves over the chest wall parietal pleura) and by the phrenic nerve (over the diaphragmatic parietal pleura)
What is Kehr’s sign
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
Mesothelioma
Mesothelial cells making up the pleura can become neoplastic after exposure to asbestos, leading to mesothelioma
