Respiratory

Question 1

Primary Ciliary Dyskinesia

Answer 1

• Autosomal recessive
• Due to mutations in genes responsible for normal flagellar and ciliary function
• Impaired mucociliary function leads to chronic cough, sinusitis, otitis media, and bronchiectasis.
• Situs inversus: randomized left and right body asymmetry
• Infertility from impaired function of sperm and fallopian tube cilia

Question 2

Kartagener Syndrome

Answer 2

Triad of:
Situs Inversus
Chronic Sinusitis
Bronchiectasis

Question 3

What is the most common cause of bronchiolitis in children under 2 years old?

Answer 3

• Respiratory Syncytial Virus
• Presents with low grade fever, cough, tachypnea and increased work of breathing (nasal flaring).
• Exam shows diffuse wheezes and crackles
• May lead to apnea and/or respiratory failure

Question 4

What respiratory component allows the terminal bronchioles to clear foreign debris and particles?

Answer 4

• The cilia or mucociliary clearance

Question 5

What portion of the respiratory tree is covered by cilia?

What is its purpose?

Answer 5

• From the trachea to the proximal portion of the respiratory bronchioles
• Allows for mucociliary clearance of foreign particles by the action of cilia beating towards the pharynx

Question 6

What are goblet cells?

What is their function?

Answer 6

• Mucus secreting cells interspersed through the respiratory mucosa from the trachea to the large bronchioles
• ## Not found in terminal bronchioles

Question 7

How are particles cleared beyond the terminal bronchioles? That is to say how are they cleared from the respiratory bronchioles and on?

Answer 7

• Dependent on phagocytosis by alveolar macrophages
• Destroy some inhaled particles via lysosomal degradation
• Nondigested material is transported by macrophages to pulmonary lymphatics or to the terminal bronchioles for clearance by mucociliary clearance

Question 8

Where are submucosal and mucoserous glands found within the respiratory tract?
What is their function?

Answer 8

• They are found in the trachea and bronchi
• Not found in bronchioles
• They help form the mucous layer in the larger aiways

Question 9

What are type I pneumocytes?

Answer 9

• Squamous, thin cells that line the alveoli
• Make up 97% of the alveolar surface
• Facilitate gas diffusion

Question 10

What are type II pneumocytes?

Answer 10

• Cuboidal and clustered cells
• Secrete surfactant from lamellar bodies
• Serve as a precursor to type I pneumocytes and other type II cells
• Proliferate when lung is damaged
• Decrease alveolar surface tension
• Prevent alveolar collapse
• Decrease lung recoil
• Increase lung compliance

Question 11

What is surfactant made out of and when is it made?

Answer 11

• Complex mix of lecithins (Dipalmitoylphosphatidylcholine)
• Synthesis begins week 26 of gestation
• Mature levels not achieved until week 35 of gestation

Question 12

What are club cells?

Answer 12

Nonciliated; low columnar cuboidal cells with secretory granules

• Located in the small airways
• Secrete a component of surfactant
• Degrade toxins
• Act as reserve cells

Question 13

What is infant respiratory distress syndrome?
What are the risk factors?
What are the complications?
How is it treated?

Answer 13

• A surfactant deficiency
• Leads to increased surface tension and alveolar collapse
• Ground glass appearance on lung fields x-ray
• Risk factors are prematurity, maternal diabetes (due to increased fetal insulin), C-section delivery (decreases fetal glucocorticoid steroids because it is less stressful than vaginal delivery)
• Complications are patent ductus arteriosus and necrotizing enterocolitis
• Treat with maternal steroids before birth and exogenous surfactant for infant
• O2 supplementation can result in (RIB) Retinopathy, Intraventricular hemorrhage and Bronchopulmonary displasia

Question 14

How do you screen for fetal lung maturity?

Answer 14

1. Lecithin sphingomyelin (L/S) ratio in amniotic fluid
> 2 is healthy
< 1.5 predictive of NRDS
2. Foam stability index test
3. Surfactant albumin ratio

Question 15

What increases the risk of patent ductus arteriosus?

Answer 15

Persistently low O2 tension

Question 16

What consists as the conducting zone of the lungs?
What does it do?
What is another name for it?

Answer 16

Consists of:
- Trachea
- Bronchi
- Bronchioles
- Terminal Bronchioles
Warms, humidifies and filters the air
Does not participate in gas exchange
- Also known as anatomical dead space

Question 17

What consists of the large airways?

Answer 17

• Nose
• Pharynx
• Larynx
• Trachea
• Bronchi

Question 18

What consists of small airways?

Answer 18

• Bronchioles that are further divided into terminal bronchioles
• Large numbers in parallel leads to least airway resistance

Question 19

Where does cartilage and goblet cells begin and end in the respiratory tree?

Answer 19

• Begin in the trachea and extends to the end of the bronchi

Question 20

What type of epiuthelium makes up the bronchus up until the proximal terminal bronchioles?

Answer 20

• Pseudostratified ciliated columnar epithelium

Question 21

What type of epithelium makes up the distal bronchioles?

Answer 21

• Simple ciliated columnar epithelium

Question 22

What type of epithelium makes up the terminal bronchioles?

Answer 22

• Simple cuboidal epithelium

Question 23

Airway smooth muscle extends up to what part of the respiratory tract?

Answer 23

• Up till the terminal bronchioles

- It is sparse after that

Question 24

What consists as the respiratory zone?

Answer 24

The lung parenchyma which is:
Respiratory bronchioles
Alveolar ducts
Alveoli
Participates in gas exchange

Question 25

What epithelium is found in the respiratory bronchioles?

Answer 25

- Simple cuboidal cells and then simple squamous up until the alveoli

Question 26

A panic attack causes what to pCO2? | What effect does that have on the brain?

Answer 26

- Causes hyperventilation and therefore decreases pCO2 (Hypocapnia) - Causes cerebral vasoconstriction and decreases bloodflow to the brain

Question 27

Hyperventilation causes alkalosis or acidosis?

Answer 27

- Leads to respiratory alkalosis because CO2 is an acid being removed from the blood

Question 28

Hypoxemia case Give an example of reduced PiO2? How is the A-a gradient? Is it correctible with supplemental O2?

Answer 28

- High altitude - Normal - Yes

Question 29

Hypoxemia case Give an example of Hypoventilation? How is the A-a gradient? Is it correctible with supplemental O2?

Answer 29

- CNS depression, neuromuscular weakness - Normal - Yes

Question 30

Hypoxemia case Give an example of Dead space ventilation or V/Q mismatch? Hows is the A-a gradient? Is it correctible with supplemental O2?

Answer 30

- Pulmonary embolism - Increased - Yes

Question 31

Hypoxemia case Give an example of diffusion limitation? How is the A-a gradient? Is it correctible with supplemental O2?

Answer 31

- Emphysema, Interstitial Lung Disease - Increased - Yes

Question 32

Hypoxemia case Give and example of Intrapulmonary shunt or V/Q = 0 ? How is the A-a gradient? Is it correctible with supplemental O2

Answer 32

- Pneumonia, pulmonary edema, atelectasis - Increased - No

Question 33

Hypoxemia case Give an example of intracardiac shunt (right to left)? How is the A-a gradient? Is it correctible with O2?

Answer 33

- Tetrology of Fallot, Eisenmenger syndrome - Increased - No