Respiratory Development S1M3

  1. Epithelium of the trachea, larynx, branchi, and lungs is made of what embryonic tissue
  2. The cartilaginous, muscular, and connective tissue components of the trachea and lungs are derived from what embryological tissue
    Splanchnic mesoderm surrounding the foregut
  3. When does the lung bud begin forming and from where
    Week 4, As an outgrowth from the ventral wall of the foregut
  4. The lung bud is also known as
    • Respiratory bud
    • Laryngealtracheal diverticulum
    • Respiratory divertuculum
  5. The foregut where the trachea buds eventually ends up forming
  6. What divides the trachea from the esophagus
    Tracheoesophageal septum
  7. What is a fistula
    An abnormal developmental connection
  8. Atresia
    Absence of an opening
  9. Tracheoesophageal fistulas are often associated with
    Esophageal atresia
  10. What is the most prevelant type of tracheoesophageal fistula
    Atresia of the esophagus on the cranial end, and a fitsula formed with the trachea and esophagus that the caudal end (90% of the time)
  11. What are the clinical features of a baby born with tracheoesophageal fistulas
    • Episodes of gagging and cyanosis after feeding
    • Reflux of gastric contents into lungs
    • Accumulation of mucous or saliva in mouth
    • Pneumonia or Pneumonitis
    • Polyhydramnios
  12. Polyhydramnios
    Excess fluid in amniotic sac
  13. VACTERL association
    • A group of genital abnormalities that are often expressed together
    • Vertebral
    • Anal Atrasia
    • Cardiac effects
    • Tracheo-Esophageal fistulas
    • Esophageal Atresia
    • Renal abnormalities
    • Limb defects
  14. 1/3 of the TEF's have what as well
    Cardiac defects
  15. The respiratory primordium maintains its communication with the pharnx through the
    Laryngeal orifice
  16. The development of the larynx epithelium originates from
    Endoderm and cartilages (thyroid, cricoid, arytenoid) from the 4th and 6th pharyngeal arches
  17. When do the main bronchi and secondary bronchi begin to develop, and from where
    During the 5th week forming from the lung buds forming 3 secondary bronchi on the right and 2 on the left
  18. What happens in lung development during the 6th week
    Tertiary branching of the bronchi forming 10 on the right and 8 on the left
  19. Each tertiary bronchus with surrounding mesenchyme is the primordium of
    A bronchopulmonary segment
  20. By 24 weeks of development, how many orders of branches of bronchus are present
    17, the last 6 develop after birth
  21. What are the signals that trigger bronchi branching, and where do they come from
    Fibroblast growth factor (FGF), from the splanchnic mesoderm surrounding them
  22. As lung buds grow, what do they invade
    Pericardioperitoneal canals
  23. What mesoderm covers the outside of the lung and forms visceral pleura
  24. What mesoderm covers the body wall and ends up forming the parietal pleura
    Somatic mesoderm
  25. Congenital diaphramatic hernia
    Intestines herniate in to the thorax compressing lung, more common on the left then the right
  26. What are the four developmental periods of the development of the lungs
    • Pseudoglandular (5-16 wks)
    • Canalicular (16-26 wks)
    • Terminal sac (26wks-birth)
    • Alveolar (8 months to childhood)
  27. What happens in the pseudoglandular period (5-16 weeks)
    • Developing lung resembles branching pattern of a compound exocrine gland
    • Respiratory tree has developed terminal bronchioles
    • No Alveolar present
  28. What happens in the canalicular period of development of the lungs (Wks 16-26)
    • Terminal bronchioles give rise to 2 more respiratory bronchioles giving rise to 3-6 alveolar ducts
    • Lined by simple cuboidal epithelium surrounded by mesoderm with a prominent capillary network
  29. In the Terminal sac period of develop, what happens (week 26-birth)
    • More primitive alveoli develop
    • Cuboidal epithelium change into thin flat cells with numerous capillaries and lymph
    • Epithelium differentiates into Type I and II pneumocytes
  30. What is a terminal sac
    Primitive alveoli
  31. When does the production of surfactant begin
    Week 20
  32. What happens in the alveolar period (birth -8 years)
    • Mature alveoli with developed capillary contact
    • Increase in the # of respiratory bronchioles
  33. Most alveoli don't develop until
    After birth, 90%
  34. Why is fetal breathing important
    • It is essential for normal lung development through exercise of breathing movements
    • Also crucial for pneumocyte development
  35. What are the three routes that the baby clears the lungs of amniotic fluid post birth
    • Through the nose and mouth
    • Pulmonary capillaries
    • Lymphatics and pulmonary arteries
  36. What is a common cause of premature fetal death relating to the respiratory system
    Respiratory distress syndrome
  37. Pulmonary hypoplasia is found often in association with
    Bilateral renal agenesis
  38. What causes congenital cysts of the lung
    Abnormal dilation of the bronchi
  39. Which bronchi is larger
    The right, more prone to objects getting lodge in it
Card Set
Respiratory Development S1M3
Developmental Biology