Resp. Anatomy

Question 1

describe cause of congenital diaphragmatic hernia

Answer 1

• caused by a defective formation or fusion of pleuroperitoneal folds with the other parts of the diaphragm

Question 2

describe the pseudo-glandular stage

Answer 2

• week 6-16
• major elements of the lung are formed but no respiratory bronchioles

Question 3

describe the canalicular period

Answer 3

• week 16-26
• terminal bronchiole divides into 2 or more respiratory bronchioles, which divide into 3-6 alveolar ducts
• type II alveolar cells appear which produce surfactant
  
  • surfactant secretion starts during 20th week, increases gradually with a sharp increase during last 2 weeks

Question 4

describe the terminal sac

Answer 4

• week 26-birth
• terminal sacs formed lined by squamous epithelium, capillaries establish close contact

Question 5

describe the alveolar period

Answer 5

• week 32-8 to 10 years old
• primitive alveoli with well developed epithelial - endothelial capillary contacts (blood-air barrier after birth)
  
  • mature alveoli are formed after birth as the lungs expand (alveoli formation continues up to 8-10 years)x

Question 6

describe the function of the tracheoesophagal septum

Answer 6

• divides the foregut into:
  
  • ventral: laryngotracheal tube
  • dorsal: oropharynx and esophagus
• defect = TEF
  
  • TEF associated with polyhydraminos: excessive quantitiy of amniotic fluid

Question 7

contrast oligohydraminos and polyhydraminos

Answer 7

• oligohydraminos: insufficient amount of aminiotic fluid that may lead to retarded development of lungs (hypoplasia)
• polyhydraminos: excessive quantity of aminiotic fluid that is associated with TEF