Development Flashcards
At what week in development have the alveoli developed enough to support life?
Week 26-28
What will be the diagnosis of an infant who is born before his/her alveoli have developed enough to support life?
Respiratory Distress Syndrome
Alveoli continue to develop until what age?
8 years
What does the diaphragm develop from?
Septum Transversum –> (Forms central tendon)
Pleural Peritoneal Folds –> (Attaches to esophagus and septum transversum)
Mesoesophagus –> (Mesentery covering esophagus-splanchnic mesoderm)
Body Wall
What embryological layer do the Type I Pneumocytes develop from?
Endoderm
What embryological layer do the Pulmonary Capillaries develop from?
Mesoderm
What embryological layer does the Cartilage of Bronchi develop from?
Mesoderm
What embryological layer does the Epithelial Lining of Bronchi develop from?
Endoderm
What embryological layer does the Pleura develop from?
- parietal layer?
- visceral layer?
Mesoderm
- Parietal from somatic mesoderm
- Visceral from splanchnic mesoderm
When during development do the respiratory bronchi form?
Weeks 17-26
This is also the time of intense growth of pulmonary blood vessels
What is the pseudoglandular phase?
Weeks 8-16
Development of pulmonary arteries
(All of the body’s glands develop from the GI tract)
What are 3 important things for lung development?
Adequate space in thoracic cavity
Fetal breathing mvmts
Adequate volume of amniotic fluid
What is the role of Type II Pneumocytes?
To secrete surfactant
- acts like a detergent
- decreases surface tension
- allows alveoli to open up
What produces amniotic fluid and why is it important?
Fetal kidneys produce amniotic fluid.
- “breathed” in by fetus
- helps expand lungs
- helps strengthen resp muscles
What is the condition characterized by insufficient amniotic fluid?
What are the complications/consequences?
Oligohydramnios
Causes lungs to be underdeveloped (hypoplastic).
How does the fluid in the alveoli get cleared after birth?
It gets reabsorbed into the lymphatics.
List and briefly describe some common congenital abnormalities.
Tracheoesophageal Fistula - trachea still attached to esophagus
Hypoplastic Lungs - failure of lungs to expand
Congenital Lung Cysts - dilation of bronchi; may lead to pneumothorax
What is the main problem associated with diaphragm development?
Describe it.
Failure of all germ layers to fuse.
- causes diaphragmatic hernia
- contents of abdomen enter thorax
- hypoplastic lungs (don’t expand)
If the pleuroperitoneal membranes fail to fuse with the septum transversum and the esophageal mesentery, what results?
Foramen of Bochdalek, most commonly seen on the left side.
