Lung Development Flashcards
Lungs and GÌ tract derived from a pouch of the foregut called?
Respiratory diverticulum
Specilised endothelial derived from
Endoderm - outgrowth from GÌ Tract
Epithelial tissue buds from this
Budding process of epithelial tissue from endoderm is called?
Branching morphogenesis
Pseudoglangular phase
Tube epithelium
|
Bronchus (2 x L, 3 x R)
|
Bronchioles
|
Alveoli
Where key elements of lungs have formed: 8 weeks
Alveoli form?
16 weeks until approximately 8 years.
Canalicular phase
16 weeks
Terminal bronchioles form
Respiratory bronchioles form at
19 weeks
Terminal sac is formed at?
28 weeks
Alveolar sac forms?
From 16 weeks to 7/8 years
Maturation of alveoli not complete until?
7 years
Childhood asthma may resolve at this time
Lung buds are formed from ?
Endothelium
Cartilage and muscles derive from?
Surrounding mesoderm
Lungs grow to fill the pleural cavity
True or false?
True
Maturation of the lungs phases?
- Pseudoglandular period
- Canalicular period
- Terminal sac period
- Alveolar period
Name the period:
Branching has continued to form terminal bronchioles
No respiratory bronchioles or alveoli are present
Pseudoglandular period
5-16 wk
Name the period:
Each termina, bronchioles divides into two or more respiratory bronchioles, which in turn divide into three or six alveolar ducts
Canalicular period
16-26 wk
Name the period:
Terminal sacs (primitive alveoli) form, and capillaries establish close contact
Terminal sac period
26 wk to birth
Name the period:
Mature alveoli have well- developed epithelial endothelial (capillary) contact
Alveolar period
8 mo to childhood
What is Oesophageal atresia and Tracheoesophogeal fistulas?
- Fistula is the joining of the oesophagus to the trachea.
- 90% of cases the upper portion is a blind pouch (atresia)
- Cardio vascular defects often associated
What is defined as too much amniotic fluid in sac?
Polyhydramnios
Where the lung is formed is related to positional signalling from?
External RA
What are Wnts ?
Cell signalling molecules.
Involved in patterning, polarity, cell division and differentiation. Links to cancer
Importance of Wnts cells?
Wnt is important in determining how the lung tissue develops differently from the gut ie ciliated or squamous cell types.
Types of alveoli
Type I alveoli
Type II alveoli
