Cardiopulmonary 1 - Midterm; Anatomy & Embryology Flashcards
What embryonic tissue is the respiratory system derived from?
Endoderm (specifically - fore gut endoderm)
During which week of development does the tracheoesophageal folds fuse?
Week 5
The fusing of the tracheoesophageal folds during week 5 of development forms what structure?
Tracheoesophageal Septum
In the trachea, what embryologic tissue forms the epithelium, glands, and pulmonary epithelium?
Endoderm (specifically - fore gut endoderm)
What embryologic tissue gives rise to cartilage, connective tissue, and smooth muscle of the trachea?
Splanchnic Mesenchyme
Specifically - Splanchnic Layer of Lateral Plate Mesoderm
What defect causes abnormal passage between trachea and esophagus?
Tracheoesophageal Fistula
Which occurs in combination with Esophageal Atresia in 85% of cases
What is a “blind end esophagus” called?
Esophageal Atresia
During which week of development does the lung bud form?
Forms from endoderm during week 4.
During which week of development are primary bronchial buds formed?
Week 5
During which week of development are secondary bronchi formed?
Week 6
During which week of development are tertiary bronchi formed?
Week 7
During week 6 of development, how many secondary bronchi are formed on the right side?
3 (superior, middle, inferior)
During week 6 of development, how many secondary bronchi are formed on the left side?
2 (superior, inferior)
During week 7 of development, how many tertiary bronchi are formed on the right side?
10
During week 7 of development, how many tertiary bronchi are formed on the left side?
9
At completion of Bronchopulmonary segment branching at 24 weeks, how many orders of branching are there?
17 orders of branches, terminal bronchioles
At what week of development do the bronchopulmonary segments complete branching, thus completing formation of the conducting system of the lungs?
week 24
17 orders of branches, terminal bronchioles
What are the weeks of Pseudoglandular Stage of Lung Development?
5-17 weeks
What is formed during the Pseudoglandular Stage of Lung Development?
- terminal bronchioles formed - connective tissue - CANNOT survive if born - NO gas exchange possible
What weeks during lung development compose the Canalicular Stage?
16-25 weeks
What events occur during the Canalicular Stage of Lung Development?
- Vascularization
- Respiratory Bronchiole
formation
> formation of primordial
alveolar ducts - Terminal sacs formed
(primitive alveoli) - +/- survival of fetus if born
Which bronchioles does the terminal bronchioles develop into?
Respiratory Bronchioles (primordial alveolar ducts), which happens during the Canalicular Stage (16-25 weeks) of Lung Development.
What stage of lung development occurs from roughly 24 weeks until birth?
Terminal Sac Stage (or Saccular Stage)
What events take place during the terminal sac (saccular) stage of lung development?
- Gas Exchange
- Squamous Epithelium = Type I Pneumocytes
- Type II Pneumocytes (produce surfactant)
- infant will survive if born