Respiratory Flashcards
When is the the embryonal period in lung development and what is it?
26 days - 6 weeks
Development of proximal airways (R&L bronchi & 10 segmental bronchi)
Pulmonary arteries from from 6th arch at end of 6 weeks
When is the the pseudoglandular period in lung development and what is it?
6-16 weeks
Development of terminal bronchioles, division of lobules & acini; pseudostratified columnar epithelium
Bonus answer:
8 weeks: lymphatics into lung (week 8)
10-13 weeks: cartilage, SmM, cilia, goblet cells
15-16 weeks: tubular submucosal glands
When is the the acinar/cannalicular period in lung development and what is it?
16-28 weeks
Vascularizaiton w/growth of cannaliculi (respiratory bronchioles) and alveolar ducts (eventually alveolar saccules) from terminal bronchioles
Bonus Answer:
Type II alveolar cells –> surfactant synthesis
Type I alveolar cells differentiate from Type II
Capillaries proliferate under Type I cells
Cartilage extension to distal bronchi (week 24)
When is the the saccular period in lung development and what is it?
28-34 weeks
Subdivision saccules, respiratory bronchioli, interstitial tissue shrinks, fibroblasts differentiate, production of collagen, ECM & elastin, Double capillary network, early gas exchange (32 weeks)
When is the the alveolar period in lung development and what is it?
34 weeks-2 years post natal
Lymphatics extend through interlobular septae to pleura
Double to single capillary bed (air-blood barrier = 0.2 microns)
Induction of surfactant (from 32 weeks, maternal glucocort)
Type II pneumocytes increase
What period of lung development is this?
Embryonal
What period of lung development is this?
Pseudoglandular
What period of lung development is this?
Pseudoglandular
What period of lung development is this?
Pseudoglandular
What period of lung development is this?
Cannalicular
What period of lung development is this?
Saccular
What period of lung development is this?
Saccular
What period of lung development is this?
Alveolar
What signals induce surfactant production from Type II pneumocytes
Exercise, hyperinflation, steroids
What gene is required for production/expression of SP-A, B, C and ABCA3
TTF-1
What are the 5 primary lipoproteins comprising surfactant?
Large: SP-A & SP-D
Small: SP-B & SP-C
When is steroid administration recommended to prevent surfactant deficient IRDS in prematurity?
28-34 weeks
Lung biopsy: what disease?
Surfactant SP-B deficient
Lung biopsy: what disease?
Surfactant ABCA3 deficient
Lung biopsy: neonate in ARDS
What is this?
Early surfactant deficiency
Lung biopsy: neonate in ARDS
What is this?
BQ: What is differential?
Surfactant deficiency
DDx: congenital alveolar proteinosis
What is the mechanism of congenital pulmonary alveolar proteinosis?
Failure of surfactant degradation/clearance due to mutations in CSF2RA or CSF2RB (GC-CSF)
*can also be cause by receptor autoantibody
What is choanal atresia?
What syndrome is associated with it?
Occlusion of airway between nasal passage & nasopharynx.
Ass’d w/CHARGE syndrome
What 2 syndromes are frequently associated with laryngomalacia?
Pierre Robin, cri-du-chat
What syndrome is associated with laryngeal stenosis/atresia?
VATER/VACTERL
What is Mounier-Kuhn syndrome?
Tracheobronchomegaly with chronic lung infections
What is Kartagener syndrome?
Immotile cilia syndrome
Associated w/situs inversus, otitis/rhinitis, bronchiectasis & male infertility
EM shows “radial spoke” defect
What is this?
Williams-Campbell Syndrome: congenital bronchiectasis 2* deficiency of cartilage distal to main bronchus
What are the characteristics of CPAM Type 0?
Absence of alveoli/pulmonary alveolar agenesis/hypoplasia
Tracheobronchial origin; lethal
What are the characteristics of CPAM Type 1?
Most common, bronchial origin
Single or multiloculated cyst ~10cm lined by bronchial epithelium; mucinous metaplasia –> mucinous adenocarcinoma; KRAS mutations
What are the characteristics of CPAM Type II
Small-medium cysts up to 2cm; bronchial origin; 10-15%
Bronchiolar type structures w/rhabdomyomatous dysplasia; looks like extralobar sequestration
What are the characteristics of CPAM Type 3?
Solid appearing with small cysts ~0.2 cm, alveolar duct origin
Large, poor px
What is risk to neonate on ventilation without surfactant supplementation?
Hyalin membrane disease (DAD/barotrauma)
What is the most common respiratory pathogen of childhood?
RSV
What are the histologic features of a respiratory adenovirus infection?
Necrotizing bronchiolitis & smudged intranuclear inclusions in bronchiolar & alveolar epithelial cells
What are the associations with congenital diaphragmatic hernia?
Trisomy 18 & 21, TOF, extralobar sequestrations, ectopia cordis, tracheoesophageal fistula
What genetic alteration is associated with alveolar capillary dysplasia with misalignment of pulmonary veins?
Mutations resulting in FOXF1 deletions/silencing
(Chr 16)
What is diaphragmatic eventration and what are most common syndromic associations w/congenital diaphragmatic hernia (CDH)?
- Replacement of all or part of diaphragm with fibroelastic tissue - functions as a type of CDH–> pulmonary hypoplasia sequence
- Aneuploidys, Pallister-Killian (tetrasomy 12q) syndrome, microduplications/deletions
4 mo infant presents w/tachypnia, hypoxia and failure to thrive. Lung biopsy shows this (serotonin stain):
Neuroendocrine hyperplasia of infancy
What is the most common malignant tumor of the lung in children?
Metastases
A female child presents with chrondromatous hamartoma of the lung. What other syndrome/ other tumors might you look for in this patient?
Carney triad:
Extra-adrenal paraganglioma
GIST
What is this lung lesion? Stains?
Sclerosing pneumocytoma (hemangioma)
TTF-1, EMA
What is the most common primary lung malignancy in children?
Bronchial carcinoid
What is the translocation in NUT midline carcinoma?
t(15;19)(q14;p13.1)
