Week 3 Bronchial Tree Flashcards
(28 cards)
What is the bronchial tree?
The collective term for the bronchi and all of their subsequent branches.
At what level does the trachea bifurcate into the left and right main bronchi?
At the level of the 3rd or 4th thoracic vertebra.
How does the right main bronchus differ from the left?
The right main bronchus is shorter and more vertical.
What do the bronchi continue to divide into?
Secondary or lobar bronchi.
What is contained in the terminal segment of each bronchus?
Millions of alveoli.
What are the 5 stages of development for the tracheobronchial tree and lungs?
- Embryonic period
- Pseudoglandular period
- Canalicular period
- Saccular period
- Alveolar period
During which weeks does the embryonic period occur?
Weeks 4–7.
What significant event occurs during the embryonic period?
The respiratory diverticulum buds off the foregut.
What are some defects associated with the embryonic period?
- Tracheoesophageal fistula
- Esophageal and/or tracheal atresia
- Pulmonary sequestration
What occurs during the pseudoglandular period?
Continued branching of bronchial buds into terminal bronchioles.
What is a key defect during the pseudoglandular period?
Bronchogenic cyst.
At what stage is respiration possible?
Canalicular period.
What occurs during the saccular period?
Gas-exchange surface area of the lungs expands.
What is the approximate number of alveoli at birth?
50 million.
What is the bronchial tree’s main branching structure?
- Trachea
- Carina
- Main bronchi
- Lobar bronchi
- Segmental bronchi
- Terminal bronchioles
- Respiratory bronchioles
- Alveolar duct
- Alveolar sac
- Alveoli
How many left and right lobar bronchi are there?
- 2 left lobar bronchi
- 3 right lobar bronchi
What is the main function of segmental bronchi?
Each supplies a bronchopulmonary segment.
How many segments are there in the right lung?
10 segments.
What type of epithelium is present in terminal bronchioles?
Ciliated cuboidal epithelium.
What is the function of club cells?
They secrete a component of surfactant.
What characterizes respiratory bronchioles?
Outpocketing from their lumen: alveoli.
What is the blood supply to the bronchial tree?
- Left bronchial artery (direct branch of the thoracic aorta)
- Right bronchial artery (varied origin)
What is the venous drainage for the bronchial tree?
- Left bronchial vein drains into the left superior intercostal vein or accessory hemiazygos vein
- Right bronchial vein drains into the azygos vein.
What provides innervation to the bronchial tree?
The pulmonary plexus of the vagus nerve.
