1 Flashcards
• Which structures make up the large airways of the conducting zone of the respiratory tree? The small airways?
Large airways = nose, pharynx, larynx, trachea, bronchi; small airways = bronchioles, terminal bronchioles
Which part of the conducting zone of the respiratory tree has the least airway resistance?
At the terminal bronchioles. where a large number of them run in parallel
Name the three functions of the conducting zone of the respiratory tree.
The conducting zone warms, humidifies, and filters air
Which zone of the respiratory tree includes the anatomic dead space?
The conducting zone (by definition, dead space does not participate in gas exchange)
Cartilage and goblet cells extend to the end of the respiratory ____ (bronchioles/bronchi).
Bronchi
Conducting zone epithelium is ___ (cuboidal/pseudostratified ciliated columnar) and ___ (cuboidal/simple squamous) in terminal bronchioles.
Pseudostratified ciliated columnar (cilia beat to remove mucus and debris), cuboidal
What type of muscle is found in the walls of the conducting airways, and up to where does it extend?
• Smooth muscle; end of terminal bronchioles (beyond that point, it is sparse)
What anatomic area does the respiratory zone encompass, and what is the major function?
The lung parenchyma: respiratory bronchioles, the alveolar ducts, and the alveoli all function in gas exchange
What type of epithelial cells is found in respiratory bronchioles?
Predominantly cuboidal cells
A patient aspirates debris into his lungs. Other than cilia, what helps clear the debris?
Alveolar macrophages (also participate in the immune response)
Type ____ (I/II) pneumocytes make up 97% of the alveolar surface area.
I
What is the advantage of having numerous thin type I pneumocytes line the walls of alveoli?
Maximum gas exchange is permitted by thin cells (squamous morphology)
What are two important functions of type II pneumocytes?
To secrete surfactant (prevent alveolar collapse) and to serve as precursors to other pneumocytes (both types I and II)
A patient suffers a pneumothorax, which damages his lungs. Which cells proliferate to repair the lungs after they have been damaged?
Type II pneumocytes (they are the precursors of both type I and type II pneumocytes)
Describe club cells and their three functions. What is another (now outdated) name for them?
Nonciliated columnar/cuboidal pneumocytes with secretory granules that secrete surfactant, degrade toxins, act as reserve cells; Clara cells
• Explain the law of Laplace using the equation for calculating collapsing pressure (P).
P = 2 (surface tension)/radius; alveoli have a tendency to collapse on expiration, because as their radius decreases, P increases
What is dipalmitoylphosphatidylcholine? What is its function?
• A type of lecithin and an important component of surfactant; surfactant decreases alveolar surface tension and prevents atelectasis
A neonate is born at 32 weeks. Why will this neonate have respiratory problems?
Surfactant synthesis starts at 26 weeks but does not mature until 35 weeks—therefore, the child is more likely to have respiratory distress
A woman at 30 weeks’ gestation presents for an exam. The ratio of which two amniotic fluid markers can be used to assess fetal lung maturity?
The lecithin:sphingomyelin ratio (marker for surfactant quantity)
A lecithin:sphingomyelin ratio is derived for a neonate to evaluate fetal lung maturity. What value is indicative of lung maturity?
• Ratio >2.0
How many lobes does the right lung have? How many does the left lung have?
Three; two (Left has Less Lobes [2] and Lingula)
What structure does the left lung have that the right lung does not?
The lingula, which is the homolog of the middle lobe of the right lung
Where is the pulmonary artery in relation to the bronchus within the right lung hilus?
Anterior (RALS = Right Anterior; Left Superior)
Where is the pulmonary artery in relation to the bronchus within the left lung hilus?
Superior (RALS = Right Anterior; Left Superior)
The oblique fissure divides which two lobes in the right lung? The left lung?
The middle and inferior lobes; the superior and inferior lobes
Both the right and left lungs have a(n) ____ (oblique/horizontal) fissure. Only the right lung has a(n) ____ (oblique/horizontal) fissure.
Oblique; horizontal
In the posterior aspect of both the right and left lungs, the ____ (horizontal/oblique) fissure divides the superior and inferior lobes.
Oblique
• A patient has penetrating trauma to the diaphragm at the level of T8. What vascular structure is the trauma surgeon most concerned about?
The inferior vena cava, which passes through the diaphragm at the level of T8 (8 letters in vena cava)
What two structures perforate the diaphragm at the level of T10?
The esophagus and the vagus pass through at the level of T10 (C10, two trunks)
• At what level does the esophagus perforate the diaphragm?
T10 (10 letters in [o]esophagus)
What three structures perforate the diaphragm at the level of T12?
The aorta (red), thoracic duct (white), and azygos vein (blue) (at T-1-2, it’s the red, white, and blue—12 letters in aortic hiatus
Neurons from vertebral levels ____, ____, and ____ come together to form the phrenic nerve, which innervates the diaphragm.
• C3, C4, C5 (C3, 4, 5 keeps the diaphragm alive)
A man with diaphragmatic trauma has no pain there. To which anatomic region is the pain referred? What is the innervation of these regions?
shoulder (C5), the trapezius ridge (C3, C4)
Which tendon can be found on the inferior aspect of the diaphragm surrounding the caval and esophageal hiatuses?
The central tendon
What mnemonic can be used to recall the levels at which certain anatomic structures perforate the diaphragm?
I (IVC) ate (8) ten (10) eggs (esophagus) at (aorta) twelve (12)
The abdominal aorta bifurcates at ____ (C4/T4/L4), common carotid at ____ (C4/T4/L4), and trachea at ____ (C4/T4/L4).
L4, C4, T4 (all are bifourcations)
