Developmental aspect of lung diseases Flashcards
Describe the embryonic stage of lung development
3-8 weeks, starts from ventral part of foregut as laryngotracheal groove, lungs buds that develop to two main bronchi, up to primary bronchial tubules that are filled with fluid, they are fluid producing, segments of pulmonary lobes arise, left and right lung separates, main pulmonary arteries form
Describe the pseudo glandular stage
week 5-17, branching continues to terminal bronchioles, primitive lungs are formed, some cartilage, myofibrils, all conducting airways has accompanying blood vessels formed, granular looking, very metabolically active, major blood vessels are formed, formation of portion of respiratory parenchyma, no gas exchange as there are only conductive airways
Describe canalicular stage
week 16-26, bronchiole divide into respiratory bronchioles, blood vessels very close, air-blood barrier forms and thins, epithelial differentiation into type I pneumocyte, more tubular, more sponge like, squamous, lung vasculature continues developing
Describe saccular stage
24-38 weeks, primitive alveoli starts to form, surfactants production, decrease in interstitial space, thinning of air spaces, type II and I pneumocytes are recognised
Describe alveolar stage
36 weeks -2,3 years, maturation and develop of alveoli, increase in size, by the age of 8 the adult number
What are the congenital malformations that happens during embryonic stage?
tracheal or laryngeal stenosis, tracheoesophageal fistula, pulmonary agenesis
What are the congenital malformations that happen in pseuoglandular phase?
pulmonary sequestation, cystadonomatoid malformation, extraobular sequest, bronchogenic cyst
What is pulmonary sequestration?
Malformation of lower respiratory tract
What is cystadenomatoid malformations?
fluid or air -spaces rather lung tissue
Extralobular sequest
Accessory lung with its won pleura
What is bronchogenic cyst ?
large and single mediastinal masses
What are the developmental problems with lungs?
diaphragmatic hernia, pulmonary hypoplasia, pulmoanry hypertension, eventration (bulging diaphram)
What are the neonatal diseases associated with respiratory system?
Transiet tachypnoea of new born doe to wet lungs, respiratory distress syndrome, chronic neonatal lung disease - fibrous replacement and inflammation
State some antenatal factors
Nicotine exposure, micronutrients or vitamins C,D, folic acid
State some postnatal factors
infection, env pollution, tobacco
