Flashcards in Structure of the Lungs, Bronchi, and Pleura Deck (49):
What does the conducting zone include?
+ Nose, nasal cavity and sinuses
+ Nasopharynx and soft palate
Describe the structure of the trachea
+ C-shaped rings of hyaline cartilage
+ Supports a fibro-elastic and muscular air-transport tube
+ Trachealis muscle (posteriorly positioned) alters tracheal diameter
Where is the trachea located?
+ Palpable anteriorly
+ Above suprasternal notch
+ Starts at C6
+ Ends at T4/5 (sternal angle) at carina
What is the role of the trachea?
+ Connects the mouth and nose to the lungs
+ Transports air via the mouth and nose to the lungs
What is the difference between the left and right lung concerning lobes?
+ Left lung has 2 lobes
+ Right lunch has 3 lobes
Describe the main bronchus of the right lung in comparison to the left lung
+ Slightly more vertical
Describe the main bronchus of the left lung in comparison to the right lung
+ Slightly less vertical
What is more likely to happen to the right lung, and why?
Foreign bodies are more likely to enter the right lung due to the size and shape of the main bronchus
What structures are the result of the main bronchus diverging in the left lung?
+ Left superior lobar bronchus
+ Left inferior lobar bronchus
What structures are the result of the main bronchus diverging in the right lung?
+ Right superior lobar bronchus
+ Right middle lobar bronchus
+ Right inferior lobar bronchus
What does each lobar bronchus divide into?
Via which blood vessels are the bronchi supplied with oxygenated blood?
What is the sequence of division of the bronchi, before becoming alveoli?
> conducting bronchioles
> terminal bronchioles
> respiratory bronchioles
What type of epithelium is present in the trachea?
Pseudostratified, ciliated, columnar epithelium with goblet cells (for mucous secretion)
What type of epithelium is present in bronchi?
Pseudostratified, ciliated columnar epithelium but the height is more decreased (flattened) compared to the trachea.
What happens as the bronchi branch into the lungs?
The C-shaped cartilage rings are replaced by cartilage plates
What type of epithelium is present in the bronchioles?
Ciliated, columnar (thinner/flatter)
Describe the structure of the bronchioles as they form?
+ Surrounding band of smooth muscle
+ Cartilage and bands disappear
+ Bronchiole is held open by surrounding lung tissue
What happens to the smooth muscle of the bronchiole in asthma?
The smooth muscle in the wall may excessively narrow the lumen
What epithelia are present in terminal and respiratory bronchioles?
Non-ciliated, cuboidal (thinner and flatter) and goblet cells disappear
What are alveoli?
Basic structural and functional unit of the lung where gaseous exchange takes place
Where are alveoli found?
+ As outpocketings of respiratory bronchioles, alveolar ducts and alveolar sacs
How are alveoli separated from one another?
By septae (alveolar walls): a thin membrane containing capillaries
What is the function of septae?
+ To separate alveoli from one another
+ Act as the air-blood barrier for gas exhcange
What are pleura?
Membranes which cover/line the organs within a cavity as well as the cavity walls
What is the pleural cavity?
+ The space between the layers of pleura
What does the pleural cavity contain?
Fluid to lubricate the pleural surfaces allowing for smooth, gliding movements between the surfaces
What is the pleura covering the lungs referred to as?
What are the parietal pleura?
Membranes which cover/line the cavity walls
What are the different parietal pleura?
How are the lungs separated?
By the mediastnum
Why is the left lung slight longer and narrower than the right?
To make room for the heart and pericardium
What area the structural landmarks of the left lung?
+ Oblique fissure
+ Cardiac notch
+ Superior lobe
+ Inferior lobe
What is the hilum?
+The 'root of the lung'
+ Where structures pass into and out of the lung
What structures pass in and out of the lung via the hilum?
+ Main bronchus
+ Pulmonary artery
+ Pulmonary veins
What are the structural landmarks of the right lung?
+ Horizontal/transverse fissure
+ Oblique fissure
+ Superior lobe
+ Middle Lobe
+ Inferior lobe
Why is the right lung slightly wider but shorter than the left lung?
Mainly sue to the right dome of the diaphragm being higher on the left side
Where is the apex of the lungs and pleura with regards to surface anatomy?
Above the clavicle
Inferiorly, where does the pleura and the lungs extend to, with regards to surface anatomy?
+ The pleura extends down to the costal margin
+ The lungs end 2 rib spaces higher
How does respiration vary?
+ Respiration varies from quiet during rest through to a range of forced respirations during severe exercise or respiratory distress
How does air get sucked into the lungs via the trachea and larynx?
Inhalation/inspiration must increase the diameters of the thorax to create a negative pressure
What does diaphragmatic contraction do?
It causes decent, increasing its vertical diameter
What does elevation of the ribs (with assistance from intercostal muscles) achieve?
+ Pushes the sternum up and forwards
+ Pushes the ribs out
+ Increases the anteroposterior and lateral diameters
How is exhalation/expiration achieved?
By muscle relaxation (passive) and elastic recoil (remember high amount of elastic tissue in lungs and bronchi)
Describe the features of the diaphragm
+ Muscular at its periphery
+ Tendinous centrally
+ Left and right domes
From where does the motor and sensory supply come from?
Phrenic nerve (C3,4,5)
What is a pneumothorax?
A collapsed lung
How does a pneumothorax occur?
When air enters into the pleural cavity