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26 Cards in this Set
- Front
- Back
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From what embryonic tissue is the respiratory tract derived from?
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Foregut endoderm and associated mesoderm
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What parts of the respiratory tract are endodermally derived?
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Epithelial lining of:
Trachea Larynx Bronchi Alveoli |
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What parts of the respiratory tract are derived from splanchnic mesoderm?
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Cartilage
Muscle Connective tissue |
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What signalling molecule is responsible for the lung bud? What other molecule does this induce?
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Retinoic acid
TBX4 |
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During what week of embryonic development dos the lung bud form?
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4
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What two tubes of the throat are foregut-derived? What problems can arise here?
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Esophagus and trachea
Fistula between the trachea and esophagus Communication of the esophagus with the trachea Atresia |
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What other problems are common with tracheo-esophageal fistulas?
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VACTERL defects:
Vertebral anomalies Anal atresia Cardiac defects Tracheoesophageal fistula Esophageal atresia Renal atresia Limb defects |
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Defects in what embryonic tissue is associated with the VACTERL conditions?
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Mesoderm
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What are the prenatal and postnatal complications secondary to tracheoesophageal fistulas/esophageal atresia? What is the cure?
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Prenatal: Polyhydramnios
Postnatal: GI: can't swallow milk, excessive saliva, choking Respiratory: reflux of gastric contents into trachea/lungs --> pneumonia SURGERY!!! |
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What is the patterning sequence of the lungs?
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1) Trachea --> two primary bronchi
2) a. L primary bronchus branches into two secondary bronchi b. R primary bronchus branches into three secondary bronchi 3) a. 8 tertiary bronchi form in the L lung b. 10 tertiary bronchi form in the R lung |
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Where are the signals contained for lung development?
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Inside the mesoderm
Similar to the limbs, if you take out the AER (or the mesoderm in the case of the lungs) the limb/lung won't grow. |
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What is the signalling pathway in lung development?
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RA induces Tbx
Tbx induces FGF-10 FGF10 induces epithelial browth |
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What molecule is responsible for the branching of the lung?
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BMP4
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What is the mechanism of branching of the lung?
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FGF10 gets to a high enough level to induce BMP4 signalling.
BMP4 induces Shh, which decreases FGF10. Cells stop growing at the midline (not laterally) in the area of Shh, which is a branch point of the lung |
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What is the level of the bifurcation of the trachea?
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T4
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What kind of mesoderm forms the visceral pleura? The parietal pleura?
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Visceral mesoderm
Somatic mesoderm |
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At what gestational age does the fetus produce enough lung surfactant to survive ex utero?
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24 weeks
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Along which axis do the lungs develop?
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Rostral-caudal
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When a baby is born, are most of he alveoli functional?
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NO.
95% of the mature alveoli develop after birth |
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What problem is present in respiratory distress syndrome?
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Surfactant deficiency
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In an infant with RDS, what is the appearance of the lungs?
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Alveoli filled with a protein-rich fluid.
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What are problems secondary to RDS?
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Inability to synthesize surfactant from type II alveolar cells
Alveolar damage |
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What is the structure that separates the lungs from the heart in the developing baby?
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Pleuropericardial folds
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What is the structure that separates the abdominal and thoracic cavity in the developing baby?
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Septum transversum, diaphragm
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Between what levels does the diaphragm/septum transversum extend?
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T7 - T12
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If you have a problem with the formation of the septum transversum, what condition is seen? On which side do these most commonly occur?
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Congenital diaphragmatic hernias: bowel inside the thrax. Bad news bears!
L side. |
