Week 3 - Lungs Flashcards
What are the divisions of the respiratory system?
Upper Respiratory Tract and Lower Respiratory Tract
The Upper Respiratory Tract includes the Nose, Nasal Cavity, and Pharynx. The Lower Respiratory Tract includes the Larynx, Trachea, Bronchi, and Lungs.
What is the length and diameter of the trachea?
13cm long & 2.5cm in diameter
What is the structure of the trachea?
Fibro-elastic wall made of U-shaped bars of hyaline cartilage
The U-shaped cartilage keeps the lumen patent, with smooth muscle connecting the posterior free ends.
Where does the trachea start and end?
Starts at C6 and ends at T4
What happens to the carina during deep inspiration?
Descends to the level of T6
What is the anatomical relationship of the cervical part of the trachea anteriorly?
Isthmus of thyroid gland, over 2nd – 4th tracheal rings, sternohyoid, sternothyroid
What structures are located posteriorly to the cervical part of the trachea?
Oesophagus
What structures are anterior to the thoracic part of the trachea?
Arch of aorta, origins of branches (innominate artery, left common carotid, left subclavian), left brachiocephalic vein
How does the right bronchus compare to the left bronchus?
Right bronchus is wider & shorter; more in line with the trachea
The left bronchus is long & narrow and divides after piercing the lung.
What are the types of bronchi in the bronchial tree?
Primary (main), Secondary (lobar), Tertiary (segmental) bronchi
Includes conducting bronchiole, terminal bronchiole, respiratory bronchiole, alveolar duct, and alveoli.
What are the effects of sympathetic efferent fibers on the bronchi?
Bronchodilation and vasoconstriction
What are the effects of parasympathetic efferent fibers on the bronchi?
Bronchoconstriction and vasodilation
What can cause compression of the trachea?
Enlargement of the thyroid gland and aneurysm of the aortic arch
What is a common cause of inhaled foreign bodies in children?
Pins, parts of toys, parts of teeth during dental extraction
Why is the right bronchus more likely to allow a foreign body to enter?
It is wider & more direct continuation of the trachea
What is aspiration pneumonia commonly due to?
Aspiration of a foreign body in the right lung
What is bronchial asthma characterized by?
Spasm of smooth muscle in bronchioles, reducing their diameter during expiration
What structural change occurs in the thoracic cage due to bronchial asthma?
The thoracic cage becomes permanently enlarged, known as barrel chest
What layers make up the pleura?
Parietal pleura and visceral pleura
The parietal pleura is the outer layer, while the visceral pleura covers the outer surfaces of the lungs.
What does the cervical pleura line?
The undersurface of the suprapleural membrane, reaching 2.5 to 4cm above the medial third of the clavicle
What does the costal part of the pleura line?
Inner surfaces of ribs, costal cartilages, intercostal spaces, sides of the vertebral bodies, back of sternum
What does the diaphragmatic pleura cover?
The thoracic surface of the diaphragm
What forms the lateral boundary of the middle mediastinum?
Mediastinal pleura
Which nerves innervate the costal pleura?
Intercostal nerves
Which nerves innervate the mediastinal pleura?
Phrenic nerves
What is a clinical issue associated with pleura?
Lobar pneumonia with pleurisy, causing severe pain increased by coughing
What is the oblique fissure of the lung?
Extends from T4 to the 6th costal cartilage
Where does the transverse fissure occur?
Only in the right lung, from the 4th right costal cartilage to the oblique fissure
